tag:theconversation.com,2011:/id/topics/muscle-mass-29553/articlesMuscle mass – The Conversation2024-03-14T04:34:35Ztag:theconversation.com,2011:article/2241592024-03-14T04:34:35Z2024-03-14T04:34:35ZOnly walking for exercise? Here’s how to get the most out of it<figure><img src="https://images.theconversation.com/files/581817/original/file-20240314-18-so6oe8.jpg?ixlib=rb-1.1.0&rect=97%2C315%2C4914%2C2938&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-man-exercising-green-1812006481">west_photo/Shutterstock</a></span></figcaption></figure><p>We’re living longer than in previous generations, with <a href="https://www.aihw.gov.au/reports/older-people/older-australians/contents/demographic-profile">one in eight</a> elderly Australians now aged over 85. But the current <a href="https://pubmed.ncbi.nlm.nih.gov/26561272/">gap</a> between life expectancy (“lifespan”) and health-adjusted life expectancy (“healthspan”) is about ten years. This means many of us live with significant health problems in our later years.</p>
<p>To increase our healthspan, we need planned, structured and regular physical activity (or exercise). The <a href="https://www.who.int/news-room/fact-sheets/detail/physical-activity">World Health Organization recommends</a> 150–300 minutes of moderate-intensity exercise – such as brisk walking, cycling and swimming – per week and muscle strengthening twice a week.</p>
<p>Yet few of us meet these recommendations. <a href="https://doi.org/10.1186/s12966-019-0797-2">Only 10%</a> meet the strength-training recommendations. <a href="https://pubmed.ncbi.nlm.nih.gov/32488898/">Lack of time</a> is one of the most common reasons. </p>
<p>Walking is cost-effective, doesn’t require any special equipment or training, and can be done with small pockets of time. <a href="https://link.springer.com/epdf/10.1007/s00421-024-05453-y?sharing_token=1vDsDJTN5WzPxi5YmSEkOfe4RwlQNchNByi7wbcMAY5hnPeFvF3FY4v2z1P9M2M0oiR78kXv1Yzj0ODMgckqhKOGHUABEd9UOPOfV5kPAj1jf1IYMIYkdIBv-DUEcKCOiDdNyj6MFypeDhSyeYQrWu_bvlAYtPUmOSaldFpmycA%3D">Our preliminary research</a>, published this week, shows there are ways to incorporate strength-training components into walking to improve your muscle strength and balance. </p>
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Read more:
<a href="https://theconversation.com/am-i-too-old-to-build-muscle-what-science-says-about-sarcopenia-and-building-strength-later-in-life-203562">Am I too old to build muscle? What science says about sarcopenia and building strength later in life</a>
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<h2>Why walking isn’t usually enough</h2>
<p>Regular walking <a href="http://theconversation.com/health-check-in-terms-of-exercise-is-walking-enough-78604">does not appear</a> to work as muscle-strengthening exercise. </p>
<p>In contrast, exercises consisting of “eccentric” or muscle-lengthening contractions <a href="http://theconversation.com/its-ok-to-aim%20lower-with-your-new-years-exercise-resolutions-a-few-minutes-a-day-can-improve-your-muscle-strength-193713">improve</a> muscle strength, <a href="https://pubmed.ncbi.nlm.nih.gov/31130877/">prevent muscle wasting</a> and improve other functions such as balance and flexibility. </p>
<p>Typical eccentric contractions are seen, for example, when we sit on a chair slowly. The front thigh muscles lengthen with force generation.</p>
<figure class="align-center ">
<img alt="Woman sits on chair" src="https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/581801/original/file-20240313-24-zjbiei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">When you sit down slowly on a chair, the front thigh muscles lengthen.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-who-trains-using-chair-1631210659">buritora/Shutterstock</a></span>
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<h2>Our research</h2>
<p>Our <a href="https://pubmed.ncbi.nlm.nih.gov/31055678/">previous research</a> found body-weight-based eccentric exercise training, such as sitting down on a chair slowly, improved lower limb muscle strength and balance in healthy older adults. </p>
<p>We also <a href="https://pubmed.ncbi.nlm.nih.gov/28291022/">showed</a> walking down stairs, with the front thigh muscles undergoing eccentric contractions, increased leg muscle strength and balance in older women more than walking up stairs. When climbing stairs, the front thigh muscles undergo “concentric” contractions, with the muscles shortening. </p>
<p>It can be difficult to find stairs or slopes suitable for eccentric exercises. But if they could be incorporated into daily walking, lower limb muscle strength and balance function could be improved. </p>
<p>This is where the idea of “eccentric walking” comes into play. This means inserting lunges in conventional walking, in addition to downstairs and downhill walking. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/wAI7z3XdY9o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Eccentric walking means incorporating deep lunges into your movement.</span></figcaption>
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<p>In our <a href="https://link.springer.com/epdf/10.1007/s00421-024-05453-y?sharing_token=1vDsDJTN5WzPxi5YmSEkOfe4RwlQNchNByi7wbcMAY5hnPeFvF3FY4v2z1P9M2M0oiR78kXv1Yzj0ODMgckqhKOGHUABEd9UOPOfV5kPAj1jf1IYMIYkdIBv-DUEcKCOiDdNyj6MFypeDhSyeYQrWu_bvlAYtPUmOSaldFpmycA%3D">new research</a>, published in the European Journal of Applied Physiology, we investigated the effects of eccentric walking on lower limb muscle strength and balance in 11 regular walkers aged 54 to 88 years. </p>
<p>The intervention period was 12 weeks. It consisted of four weeks of normal walking followed by eight weeks of eccentric walking. </p>
<p>The number of eccentric steps in the eccentric walking period gradually increased over eight weeks from 100 to 1,000 steps (including lunges, downhill and downstairs steps). Participants took a total of 3,900 eccentric steps over the eight-week eccentric walking period while the total number of steps was the same as the previous four weeks. </p>
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Read more:
<a href="https://theconversation.com/its-ok-to-aim-lower-with-your-new-years-exercise-resolutions-a-few-minutes-a-day-can-improve-your-muscle-strength-193713">It's OK to aim lower with your new year's exercise resolutions – a few minutes a day can improve your muscle strength</a>
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<p>We measured the thickness of the participants’ front thigh muscles, muscle strength in their knee, their balance and endurance, including how many times they could go from a sitting position to standing in 30 seconds without using their arms. We took these measurements before the study started, at four weeks, after the conventional walking period, and at four and eight weeks into the eccentric walking period.</p>
<p>We also tested their cognitive function using a digit symbol-substitution test at the same time points of other tests. And we asked participants to complete a questionnaire relating to their activities of daily living, such as dressing and moving around at home. </p>
<p>Finally, we tested participants’ blood sugar, cholesterol levels and complement component 1q (C1q) concentrations, a potential <a href="https://faseb.onlinelibrary.wiley.com/doi/abs/10.1096/fj.14-262154">marker of sarcopenia</a> (muscle wasting with ageing).</p>
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<img alt="Person walks with small dog" src="https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/581816/original/file-20240314-16-le4nu3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Regular walking won’t contract your muscles in the same way as eccentric walking.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dog-walker-strides-his-pet-on-1399290365">alexei_tm/Shutterstock</a></span>
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<h2>What did we find?</h2>
<p>We found no significant changes in any of the outcomes in the first four weeks when participants walked conventionally. </p>
<p>From week four to 12, we found significant improvements in muscle strength (19%), chair-stand ability (24%), balance (45%) and a cognitive function test (21%).</p>
<p>Serum C1q concentration decreased by 10% after the eccentric walking intervention, indicating participants’ muscles were effectively stimulated. </p>
<p>The sample size of the study was small, so we need larger and more comprehensive studies to verify our findings and investigate whether eccentric walking is effective for sedentary people, older people, how the different types of eccentric exercise compare and the potential cognitive and mental health benefits. </p>
<p>But, in the meantime, “eccentric walking” appears to be a beneficial exercise that will extend your healthspan. It may look a bit eccentric if we insert lunges while walking on the street, but the more people do it and benefit from it, the less eccentric it will become. </p>
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Read more:
<a href="https://theconversation.com/health-check-in-terms-of-exercise-is-walking-enough-78604">Health Check: in terms of exercise, is walking enough?</a>
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<img src="https://counter.theconversation.com/content/224159/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ken Nosaka does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There are ways to incorporate strength-training components into walking to improve your muscle strength and balance.Ken Nosaka, Professor of Exercise and Sports Science, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2048112023-09-12T20:09:46Z2023-09-12T20:09:46ZWhat can you do to speed up your metabolism?<figure><img src="https://images.theconversation.com/files/546284/original/file-20230905-23-oi6es0.jpg?ixlib=rb-1.1.0&rect=0%2C10%2C6720%2C4446&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Our metabolism is the force inside our bodies that mysteriously decides whether to convert the food we eat into a burst of energy, or extra kilos on the scales. </p>
<p>A “slow” or “sluggish” metabolism is often the first thing we blame when we struggle to lose weight. </p>
<p>As a result, a <a href="https://www.grandviewresearch.com/industry-analysis/weight-loss-supplements-market-report">US$33 billion</a> industry offers thousands of products promising to speed up our metabolic rate for weight-loss success. </p>
<p>But rather than reaching for a supplement, there are things you can do to speed your metabolism up. </p>
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Read more:
<a href="https://theconversation.com/ever-wonder-how-your-body-turns-food-into-fuel-we-tracked-atoms-to-find-out-211047">Ever wonder how your body turns food into fuel? We tracked atoms to find out</a>
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<h2>What is metabolism and how does it work?</h2>
<p>Metabolism is the term describing all the chemical reactions in our bodies that keep us alive. It provides the energy needed for essential functions like breathing and digestion.</p>
<p>When we refer to metabolism in the context of our weight, we’re actually describing our basal metabolic rate – the number of calories the body burns at rest, determined by how much muscle and fat we have.</p>
<p>Many factors can affect your metabolism, including gender, age, weight and lifestyle. It naturally slows down <a href="https://www.hindawi.com/journals/jobe/2019/8031705/">as we age</a> and becomes dysfunctional <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4989512/">after dieting</a>. </p>
<h2>Why does our metabolism slow with age?</h2>
<p>As our bodies age, they stop working as efficiently as before. Around the age of 40, our muscle mass starts <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6431367/">naturally declining</a>, and the ratio of body fat to muscle increases.</p>
<p>Because muscle mass helps determine the body’s metabolic rate, this decrease in muscle means our bodies start to burn fewer calories at rest, decreasing our metabolic rate.</p>
<figure class="align-center ">
<img alt="Fit man looks at smartwatch" src="https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546287/original/file-20230905-19-6vzs81.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Muscle mass helps determine the body’s metabolic rate.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/smart-watch-on-sporty-african-man-2069217704">Shutterstock</a></span>
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<h2>Why does our metabolism become dysfunctional after dieting?</h2>
<p>When you lose large amounts of weight, you’re likely to have lowered your metabolic rate, and it <a href="https://pubmed.ncbi.nlm.nih.gov/22535969/">doesn’t recover</a> to the level it was pre-dieting – even if you regain weight. </p>
<p>This is because, typically, when we diet to lose weight, we lose both fat and muscle, and the decrease in our calorie-burning muscle mass slows our metabolism. </p>
<p>We can account for the expected decrease in metabolic rate from the decrease in body mass, but even after we regain lost weight our metabolism doesn’t recover. </p>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/27136388/">Research</a> shows that for every diet you attempt, the rate at which you burn food slows by a further 15% that can’t be accounted for. </p>
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Read more:
<a href="https://theconversation.com/is-it-true-the-faster-you-lose-weight-the-quicker-it-comes-back-heres-what-we-know-about-slow-and-fast-weight-loss-198301">Is it true the faster you lose weight the quicker it comes back? Here's what we know about slow and fast weight loss</a>
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<h2>3 ways to speed up our metabolism (and 1 thing to avoid)</h2>
<p><strong>1) Pay attention to what you eat</strong></p>
<p>Consider the types of food you eat because your diet will influence the amount of energy your body expends to digest, absorb and metabolise food. This process is called <a href="https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-1-5">diet-induced thermogenesis</a>, or the thermic effect of food, and it equates to about 10% of our daily energy expenditure.</p>
<p><a href="https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-1-5">Research</a> shows the thermic effect of food is highest for protein-rich foods because our bodies need to use more energy to break down and digest proteins. Eating protein-rich foods will increase your metabolic rate by about 15% (compared to the average of 10% from all foods). In contrast, carbs will increase it 10% and fats by less than 5%.</p>
<figure class="align-center ">
<img alt="Person stands on scales in their living room" src="https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546288/original/file-20230905-15-oi6es0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">If you’re trying to lose weight, aim for balanced meals rather than avoiding whole food groups.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/a-person-standing-on-a-weighing-scale-7801341/">Pexels/Pavel Danilyuk</a></span>
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<p>But this doesn’t mean you should switch to a protein-only diet to boost your metabolism. Rather, meals should include vegetables and a source of protein, balanced with wholegrain carbs and good fats to support optimum <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7071223/">health, disease prevention and weight loss</a>. </p>
<p><strong>2) Get moving</strong></p>
<p>Regular physical activity will boost muscle mass and <a href="https://link.springer.com/article/10.1007/s00125-020-05177-6">speed up your metabolism</a>. Increasing your muscle mass raises your basal metabolic rate, meaning you’ll burn more calories at rest. </p>
<p>You can achieve this by incorporating 30 minutes of physical activity into your daily routine, supplemented with two days of gym or strength work each week.</p>
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Read more:
<a href="https://theconversation.com/does-exercise-help-you-lose-weight-198292">Does exercise help you lose weight?</a>
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<p>It’s also important to mix things up, as following the same routine every day can quickly lead to boredom and exercise avoidance.</p>
<p>Neglecting exercise will just as quickly result in a decline in muscle mass, and your lost muscle will slow your metabolism and hamper your efforts to lose weight.</p>
<p><strong>3) Get enough sleep</strong></p>
<p>A growing body of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2929498/">research</a> confirms sleep deprivation can significantly impact your metabolism. </p>
<p>A lack of sleep disturbs the body’s energy balance. This causes our appetite hormones to <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/oby.23616">increase feelings of hunger</a> and trigger food cravings, while altering our <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2084401/">sugar metabolism</a> and decreasing our <a href="https://www.sciencedirect.com/science/article/pii/S0002916523129534">energy expenditure</a>. </p>
<p>If you want to boost your metabolism, set yourself a goal of getting <a href="https://www.sleephealthjournal.org/article/S2352-7218(15)00015-7/fulltext">seven hours</a> of uninterrupted sleep each night. </p>
<p>A simple way to achieve this is to avoid screens for at least one hour before bed. Screens are a big sleep disruptor because they suppress melatonin production in the brain, telling us it’s daytime instead of nighttime.</p>
<figure class="align-center ">
<img alt="Woman stretches after waking up" src="https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546290/original/file-20230905-23-c77bn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Poor sleep can impact your metabolism.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/kqDEH7M2tGk">Unsplash/Kinga Howard</a></span>
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</figure>
<p><strong>4) Don’t waste your money on diet pills and supplements</strong></p>
<p>Thousands of products promise to activate your metabolism and speed up your weight loss. While some may have ingredients that will boost your metabolism immediately after you take them, such as caffeine and capsaicin (the component which gives chillies their heat), <a href="https://www.nature.com/articles/ijo201682">research</a> confirms the effect is temporary – they don’t support long-term weight loss.</p>
<p>Most products promising to help you speed up your metabolism to help you lose weight don’t offer any scientific evidence to back their efficacy. <a href="https://pubmed.ncbi.nlm.nih.gov/33976376/">Two</a> extensive <a href="https://pubmed.ncbi.nlm.nih.gov/31984610/">reviews</a> published recently examined around 120 studies of weight-loss supplements and found they just don’t work, despite the bold marketing claims.</p>
<p>So leave the pills, potions and powders on the shelf and focus on the things that work. Your metabolism – and your hip pocket – will thank you.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/its-time-to-bust-the-calories-in-calories-out-weight-loss-myth-199092">It's time to bust the 'calories in, calories out' weight-loss myth</a>
</strong>
</em>
</p>
<hr>
<p><em>At the Boden Group, Charles Perkins Centre, we are studying the science of obesity and running clinical trials for weight loss. You can register <a href="https://redcap.sydney.edu.au/surveys/?s=RKTXPPPHKY">here</a> to express your interest.</em></p><img src="https://counter.theconversation.com/content/204811/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Nick Fuller works for the University of Sydney and has received external funding for projects relating to the treatment of overweight and obesity. He is the author and founder of the Interval Weight Loss program.</span></em></p>Our metabolism naturally slows down as we age and becomes dysfunctional after dieting. Here’s what you can do to give yours a boost.Nick Fuller, Charles Perkins Centre Research Program Leader, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2035622023-05-17T01:27:55Z2023-05-17T01:27:55ZAm I too old to build muscle? What science says about sarcopenia and building strength later in life<figure><img src="https://images.theconversation.com/files/525760/original/file-20230512-41125-9ts1je.jpg?ixlib=rb-1.1.0&rect=0%2C44%2C7360%2C4858&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Sarcopenia is the progressive and accelerated loss of muscle mass and strength as we age. </p>
<p>The term was coined in the 1980s, and the condition has been recognised as a disease for less <a href="https://onlinelibrary.wiley.com/doi/full/10.5694/mja2.50432">than a decade</a>, but the concept is as old as time: use it or lose it.</p>
<p>But what if you’re in your 60s, 70s, 80s or 90s? Is it “too late” to build muscle and fight sarcopenia? Here’s what the research says.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Exercise training during weight loss can also prevent bone loss.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-muscle-wasting-condition-sarcopenia-is-now-a-recognised-disease-but-we-can-all-protect-ourselves-119458">The muscle-wasting condition 'sarcopenia' is now a recognised disease. But we can all protect ourselves</a>
</strong>
</em>
</p>
<hr>
<h2>Sarcopenia isn’t just unfortunate. It’s dangerous</h2>
<p>All of us will start to gradually lose muscle from our mid-30s, but this loss accelerates in later years. For up to 30% of adults aged over 60, the declines are substantial enough to meet the <a href="https://onlinelibrary.wiley.com/doi/10.1002/jcsm.12783">definition for sarcopenia</a>.</p>
<p>Sarcopenia increases your risk of falls, fractures, hospitalisation, loss of independence and many other chronic diseases. </p>
<p>However, people who are active in early life and maintain this as they age can delay or prevent the <a href="https://onlinelibrary.wiley.com/doi/10.1002/jcsm.13218">onset of sarcopenia</a>.</p>
<p>The good news is it’s never too late to make a start, even if you are already experiencing the debilitating effects of sarcopenia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=392&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=392&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=392&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=492&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It’s never too late to make a start.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>What the science says</h2>
<p>Resistance training is the most effective way to build and strengthen muscle at all ages. That means things like:</p>
<ul>
<li><p>lifting free weights like dumbbells</p></li>
<li><p>using machine weights, like you find in a gym</p></li>
<li><p>using resistance bands</p></li>
<li><p>bodyweight exercises such as push-ups, squats, wall-sits or tricep dips.</p></li>
</ul>
<p>It’s OK to start with even very light weights, or do modified, easier versions of bodyweight exercises (for example, you might do a shallow squat rather than a deep one, or a push-up against a wall or windowsill instead of on the floor). Something is always better than nothing. </p>
<p>Aim to make the exercise harder over time. Lift progressively heavier weights or do increasingly harder versions of bodyweight or resistance band exercises. This is called progressive resistance training.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Aim to make the exercise harder over time.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p><a href="https://link.springer.com/article/10.1007/s40279-020-01331-7?fbclid=IwAR06PPIz8cf2xZExNvrnlueQp0-7SWQwT1x0bUdnZrgTOqcyiAdTrpufTjU">Clinical trials</a> have consistently shown all adults – even very frail people over the age of 75 – can make significant gains in muscle mass and strength by doing progressive resistance training at least twice a week. The improvements can be seen in as little as eight weeks. </p>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/2342214/">One seminal study</a> included ten frail, institutionalised 86–96 year olds who did a high-intensity progressive resistance training program. </p>
<p>After just eight weeks, the average mid-thigh muscle area had increased by almost 10% (which is equivalent to the amount of muscle typically lost over a decade) and leg strength increased by about 180%. </p>
<p>In other words, these older people were almost three times stronger at the end of the short training program than before.</p>
<p>It really can be done. British-Swiss man <a href="https://www.youtube.com/watch?v=rGgoCm1hofM">Charles Eugster</a> (1919–2017), for example, took up progressive resistance training in his late 80s after noticing a decline in his muscle mass. He went on to become a <a href="https://www.bodybuilding.com/fun/lessons-from-a-95-year-old-bodybuilder.html">bodybuilder</a>, and in 2012 gave a TEDx <a href="https://www.youtube.com/watch?v=rGgoCm1hofM">talk</a> titled “Why bodybuilding at age 93 is a great idea”.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6689%2C4466&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6689%2C4466&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Resistance training is the most effective way to build and strengthen muscle at all ages.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>What if my doctor has told me to lose weight?</h2>
<p>Many older adults have obesity, which increases the risk of cardiovascular disease and type 2 diabetes. </p>
<p>They’re often told to lose weight, but any dieting (or other strategy aimed at weight loss) also usually causes muscle loss.</p>
<p>Losing muscle mass in older age could increase the risk for many common chronic conditions. For example, muscle is crucial to keeping blood sugar levels under control, so excessive muscle loss could blunt the benefits of weight loss for people with type 2 diabetes.</p>
<p>If you’re losing weight, it’s important to try to minimise muscle mass loss at the same time. How? Progressive resistance training. </p>
<p>By combining progressive resistance training with weight loss, one study found the resulting muscle loss is <a href="https://pubmed.ncbi.nlm.nih.gov/29596307/">negligible</a>. (It’s also important that if you are dieting, you are still eating <a href="https://www.clinicalnutritionjournal.com/article/S0261-5614(14)00111-3/fulltext">enough protein</a>, so your body has the ingredients it needs to build new muscle).</p>
<p>Exercise training during weight loss can also prevent <a href="https://www.sciencedirect.com/science/article/pii/S2095254621000491">bone loss</a>, which reduces fracture risk in older people.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&rect=0%2C19%2C4368%2C2877&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&rect=0%2C19%2C4368%2C2877&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An accredited exercise professional can help design a program that suits you.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Aim for at least twice a week – more if you can</h2>
<p>Whether or not you’re trying to lose weight, and regardless of whether you think you have sarcopenia, all older adults can benefit from strengthening their muscles.</p>
<p>Even if getting to a gym or clinic is hard, there are plenty of resistance exercises you can do at home or outdoors that will help build strength.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1130&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">All older adults can benefit from strengthening their muscles.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Talk to a health professional before starting a moderate to high intensity progressive resistance training program. An accredited exercise professional can help design a program that suits you.</p>
<p>Generally, we should aim to do progressive resistance training at least <a href="https://link.springer.com/article/10.1007/s12603-021-1665-8">twice a week</a>.</p>
<p>Try to target 8–10 muscle groups, and start out at about 30–40% of your maximum effort before progressing over time to 70–80% of your maximum. </p>
<p>As the name suggests, it is key to progressively increase the effort or challenge of your program so you can feel the improvements and achieve your goals. </p>
<p>It’s never too late to start training for your fight against sarcopenia and loss of independence in older age. The health benefits will be worth it. As Socrates <a href="https://www.sacred-texts.com/cla/plato/theaetet.htm">said</a> in the 4th Century BC:</p>
<blockquote>
<p>is not the bodily habit spoiled by rest and idleness, but preserved for a long time by motion and exercise?</p>
</blockquote>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/use-it-or-rapidly-lose-it-how-to-keep-up-strength-training-in-lockdown-165810">Use it or rapidly lose it: how to keep up strength training in lockdown</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/203562/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Scott has been a consultant for Pfizer Consumer Healthcare and Abbott Nutrition. He has received competitive research funding from the National Health and Medical Research Council (NHMRC), Medical Research Future Fund (MRFF) and Amgen Australia. He is a Council member of the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR), and Chair of the ANZSSFR Sarcopenia Diagnosis and Management Taskforce.</span></em></p><p class="fine-print"><em><span>Robin Daly has received funding from the National Health and Medical Research Council (NHMRC), Medical Research Future Fund (MRFF), Eggs Australia, Meat and Livestock Australia, the Peanut Institute, Fonterra Co-operative Group Ltd as part of a Primary Growth Partnership grant via the Ministry of Primary Industries in New Zealand and Amgen Australia. He has previously received speaker honoraria from Abbott Nutrition, Fresenius Kabi, Nutricia Australia and Amgen. He is a member of the medical and scientific advisory committee of Healthy Bones Australia and a council member of the International Federation for Musculoskeletal Research Societies (IFMRS).
</span></em></p>It’s never too late to start.David Scott, Associate Professor (Research) and NHMRC Emerging Leadership Fellow, Deakin UniversityRobin M. Daly, Professor of Exercise and Ageing, Institute for Physical Activity and Nutrition, Deakin University, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1846692022-06-13T13:14:33Z2022-06-13T13:14:33ZBuilding muscle: slowing down the tempo of your workout won’t help you get stronger faster – but it may still have benefits<figure><img src="https://images.theconversation.com/files/468443/original/file-20220613-24020-el71u6.jpg?ixlib=rb-1.1.0&rect=44%2C0%2C5000%2C3300&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Advocates of the weightlifting technique claim moving slower makes muscles work harder.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-african-american-man-sitting-lifting-1447450724">Twinsterphoto/ Shutterstock</a></span></figcaption></figure><p>Everyone wants to get fit, but many of us lack the time or patience required to get results – especially if our goal is to build a more muscular physique. While there’s plenty of advice online telling people about the best ways to do this, not all of the information is trustworthy or backed by evidence. One suggestion often made by fitness enthusiasts is a training method called “time under tension”. This is the idea that slowing down the pace of your exercises – such as your squat or bicep curls – is the secret to helping you get stronger faster. </p>
<p>Put simply, time under tension refers to the length of time a muscle is working during a certain exercise. For example, if you were doing a push up, you might aim to take two seconds on the way down, then two seconds as you push back up from the ground – meaning you’re keeping the muscle under more tension (theoretically making it work harder) than if you were to rush through your push ups. So if you did ten push ups, it would take you around 40 seconds to complete a set. </p>
<p>Advocates of time under tension claim that by maintaining longer periods of muscle tension – usually 40 to 60 seconds per set – you’re more likely to experience muscle growth. It sounds great in theory, but in practice it’s not that straightforward.</p>
<h2>The muscle building equation</h2>
<p>In order to build muscle, <a href="https://pubmed.ncbi.nlm.nih.gov/27433992/">training volume</a> is the most important factor. This refers to the overall amount of weight lifted throughout the workout. So for example, if you do four sets of a barbell squat, and perform eight repetitions each set lifting 100kg, your overall training volume for that exercise would be 3,200kg. However, the number of muscle fibres we recruit during an exercise (which depends on the amount of force needed to perform an exercise or lift a weight) is also important. </p>
<p>Blood flow also plays an important role in muscle growth. As our muscles contract during a resistance training exercise, the blood vessels that feed the working muscles become compressed. This reduces circulation to the muscle, temporarily <a href="https://pubmed.ncbi.nlm.nih.gov/7957136/">preventing enough oxygen</a> from reaching the muscle (known as hypoxia). Although we’re not clear on the reasons why, we do know that hypoxia leads to <a href="https://journals.humankinetics.com/view/journals/ijspp/5/4/article-p497.xml">increased muscle growth</a>, and that exercises with prolonged time under tension reduce blood supply to muscles for longer periods of time. This is why many people believe that longer time under tension will lead to greater muscle growth. </p>
<p>However, the research tells a different story.</p>
<p>Studies have repeatedly found that slowing down the tempo of a lift or movement has no more benefit for building muscle than lifting at a regular or even fast pace. This is true whether the workout is for the <a href="https://pubmed.ncbi.nlm.nih.gov/18978616/">whole body</a>, based on <a href="https://pubmed.ncbi.nlm.nih.gov/30325791/">compound lifts</a> (exercises that engage multiple muscle groups at once, such as a back squat), or using <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7061915/">resistance machines</a>.</p>
<figure class="align-center ">
<img alt="Young woman performs a barbell squat using the smith machine at the gym." src="https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468444/original/file-20220613-31449-m5oyhb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Your regular tempo will work just as well for building muscle.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fitness-asian-woman-doing-exercise-lifting-1164752842">Peera_stockfoto/ Shutterstock</a></span>
</figcaption>
</figure>
<p>In fact, some research has even suggested that while no difference in muscle growth is achieved at slower speeds, muscle fibre activation, overall training volume and even strength gains <a href="https://pubmed.ncbi.nlm.nih.gov/16177617/">are all lower</a> in people who train at a slower – rather than their natural – tempo.</p>
<h2>Waste of time?</h2>
<p>But that doesn’t mean we should reject the role of time under tension entirely. While research suggests that overall muscle growth may not be any better than exercising at a normal tempo, spending more time under tension (around 60-90 seconds per set) may lead to greater muscle growth in specific muscle fibres. </p>
<p>Our muscles are comprised of different types of muscle fibres. One type are slow-twitch muscle fibres (known as type I fibres), which are important for endurance as they don’t fatigue as quickly as other muscle fibres. This makes them essential for activities such as long runs or bike rides, high rep sets, or isometric holds (such as the plank). </p>
<p>Short durations of exercise with very heavy weights are unlikely to make our slow-twitch muscle fibres tired. But research shows that <a href="https://pubmed.ncbi.nlm.nih.gov/17100349/">time under tension</a> may help us <a href="https://pubmed.ncbi.nlm.nih.gov/19799341/">better develop</a> these important muscle fibres. </p>
<p>Of course, many of us aren’t highly experienced weightlifters or bodybuilders but time under tension may still be beneficial to us – and can also be a great place for people to start, especially if they haven’t lifted heavy weights before. In fact, in clinical exercise settings we use time under tension as a way of reinforcing good technique. This helps reduce the risk of injury and helps people learn how to optimally recruit their muscles. </p>
<p>All in all, there’s no real “hack” to building muscle, despite what proponents of time under tension may claim. If you want to build muscle, it requires consistency, proper nutrition, and trying to challenge yourself each workout by doing a bit more or lifting a bit heavier.</p><img src="https://counter.theconversation.com/content/184669/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jack McNamara does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>‘Time under tension’ may be a popular weightlifting technique, but research shows it’s no better than exercising at your normal pace.Jack McNamara, Lecturer, University of East LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1756102022-01-27T19:01:09Z2022-01-27T19:01:09ZGut microbes help hibernating ground squirrels emerge strong and healthy in spring<figure><img src="https://images.theconversation.com/files/442826/original/file-20220126-27-13smcdk.jpg?ixlib=rb-1.1.0&rect=63%2C369%2C3142%2C1959&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When not hibernating, ground squirrels need to feast to store energy.</span> <span class="attribution"><a class="source" href="https://doi.org/10.1126/science.abh2950">Robert Streiffer</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Ground squirrels spend the end of summer gorging on food, preparing for hibernation. They need to store a lot of energy as fat, which becomes their primary fuel source underground in their hibernation burrows all winter long.</p>
<p>While hibernating, ground squirrels enter <a href="https://doi.org/10.1111/brv.12137">a state called torpor</a>. Their metabolism drops to as low as just 1% of summer levels and their body temperature can <a href="https://doi.org/10.1152/physrev.00008.2003">plummet to close to freezing</a>. Torpor greatly reduces how much energy the animal needs to stay alive until springtime.</p>
<p>That long fast comes with a downside: no new input of protein, which is crucial to maintain the body’s tissues and organs. This is a particular problem for muscles. In people, long periods of inactivity, like prolonged bed rest, <a href="https://doi.org/10.1186/s13728-015-0036-7">lead to muscle wasting</a>. But muscle wasting is minimal in hibernating animals. Despite as much as six to nine months of inactivity and no protein intake, they preserve muscle mass and performance remarkably well – a very handy adaptation that helps ensure a successful breeding season come spring.</p>
<p>How do hibernators pull this off? It’s been <a href="https://doi.org/10.1086/650471">a real head-scratcher</a> <a href="https://doi.org/10.1152/ajpregu.1991.261.5.R1214">for hibernation biologists for decades</a>. <a href="https://scholar.google.com/citations?user=TUVZbtcAAAAJ&hl=en&oi=ao">Our research</a> <a href="https://scholar.google.com/citations?user=zuJyGe8AAAAJ&hl=en&oi=ao">team tackled</a> this question by investigating how hibernating animals might be getting a major assist <a href="https://doi.org/10.1126/science.abh2950">from the microbes that live in their guts</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="small mammal curled into a ball, nestled in wood chips" src="https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442827/original/file-20220126-23-o570i5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The 13-lined ground squirrel shows minimal signs of muscle wasting, even after hibernating for up to six months.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1126/science.abh2950">Robert Streiffer</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>A nitrogen-recycling system</h2>
<p>We knew from previous research that a hibernator’s <a href="https://doi.org/10.1016/j.cbpa.2020.110875">gastrointestinal system undergoes dramatic changes</a> in its structure and function from summer feeding to winter fasting. And it’s not only the animals who are fasting all winter long – their gut microbes are, too. Along with our microbiology collaborators, we figured out that <a href="https://doi.org/10.1146/annurev-nutr-071816-064740">winter fasting changes the gut microbiome</a> quite a bit.</p>
<p>And then we wondered … could gut microbes play a functional role in the process of hibernation itself? Could certain bacteria help keep muscle and other tissues working when the mostly immobile animals aren’t eating?</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="brown cow munching grass" src="https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=671&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=671&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=671&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=843&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=843&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443024/original/file-20220127-6424-ql553k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=843&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Microbes in their guts help ruminants, including cows, hold on to the nitrogen they need to build proteins.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/brown-cow-royalty-free-image/1219160750">Lemanieh/ iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Biologists had previously identified a clever trick in ruminant animals, such as cattle, that helps them survive times when protein intake in the diet is low or protein needs are especially high, such as during pregnancy. A process <a href="https://doi.org/10.1079/NRR200498">called urea nitrogen salvage</a> allows the animal to recoup nitrogen – a critical ingredient for building protein – that would otherwise be excreted in urine as the waste product urea. Instead, the urea’s nitrogen is retained in the body and used to make amino acids, the building blocks of proteins.</p>
<p>This salvage operation depends on the chemical breakdown of urea molecules to release their nitrogen. But here’s the kicker: Chemical breakdown of urea requires urease, an enzyme that animals do not produce. So how does a cow, for instance, get that nitrogen out of urea?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="ball and stick model of a chemical structure" src="https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443025/original/file-20220127-16-1kqqp1u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A model of the urea molecule, with two nitrogen atoms (in blue) along with a carbon (gray), an oxygen (red) and four hydrogen (white) atoms.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/urea-molecule-royalty-free-illustration/147217473">LAGUNA DESIGN/Science Photo Library via Getty Images</a></span>
</figcaption>
</figure>
<p>It turns out certain microbes that are normal residents of animals’ guts can do just that. They make the urease enzyme and use it to chemically split urea molecules, freeing up the nitrogen, which becomes part of ammonia molecules. Microbes then absorb ammonia and use it to make new protein for themselves.</p>
<p>Peculiarities of the ruminant digestive system allow those animals to benefit greatly from this process. But for other animals – like hibernators and us – it was less clear whether and how the urea nitrogen could make its way into the animals’ bodies to support protein synthesis.</p>
<p>This was our challenge as scientists: Could we demonstrate urea nitrogen recycling in hibernators and show that it is particularly helpful to them the longer they fast?</p>
<h2>Our experimental game plan</h2>
<p>Using the 13-lined ground squirrel, <a href="https://doi.org/10.1126/science.abh2950">we designed experiments to investigate</a> key steps in urea nitrogen salvage.</p>
<p>First, we injected into the squirrel’s bloodstream urea molecules in which the two nitrogen atoms were replaced by a heavier form of nitrogen that naturally occurs only in tiny amounts in the body.</p>
<p>We were able to follow these heavier nitrogen atoms as the injected urea moved from the blood into the gut, then as microbial urease broke down the urea into its component parts, and finally into the squirrels’ tissue metabolites and proteins. Wherever we saw higher levels of the heavier form of nitrogen, we knew that urea was the source of the nitrogen, and therefore gut microbes had to be responsible for getting the urea nitrogen back into the animals’ bodies.</p>
<p>To confirm that the microbes were doing the nitrogen recycling, we compared squirrels that had normal gut microbiomes to squirrels that didn’t. We treated some animals with antibiotics to reduce gut microbes at three times of the year: summer; early winter, when they were one month into fasting and hibernation; and late winter, whwithen they were four months into fasting and hibernation.</p>
<p>In squirrels with normal microbiomes, we saw evidence of urea nitrogen salvage at each step of the process that we tested. But squirrels with depleted microbiomes displayed minimal urea nitrogen salvage. Our observations confirmed that this process was indeed dependent on the gut microbes’ ability to break down urea and liberate its nitrogen in the hibernators’ guts. Hibernators’ liver and muscle tissue incorporated the most urea nitrogen during late winter – that is, the longer they’d been hibernating and without food.</p>
<p>We also found that the ground squirrels contribute to this remarkable symbiosis. During hibernation, their gut cells increase production of proteins called urea transporters. These molecules are lodged in intestinal cell membranes and shepherd urea from the blood into the gut where the microbes that contain urease are found. This assist means that what little urea the animal makes during hibernation has an easier route to the gut.</p>
<p>Finally, we found that it wasn’t just squirrels who benefited from this process. The microbes too were using the urea nitrogen to build their own proteins, showing that urea nitrogen salvage provides both parties with this important molecular building block during the long winter fast.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Fal-vhNgxvs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Every few weeks, hibernating squirrels arouse temporarily, as seen in this time-lapse video. They don’t eat or drink or leave the burrow, but the short increase in body temperature lets enzymes like urease do their jobs.</span></figcaption>
</figure>
<h2>Could this kind of symbiosis help humans?</h2>
<p>This example of hibernator-microbe symbiosis has potential clinical applications. For example, undernourishment, which affects millions of people globally, leads to a progressive decline in muscle mass and compromises health. Sarcopenia, which is muscle wasting that is a natural part of aging, impairs mobility and makes people more susceptible to injury. A detailed understanding of how the hibernator nitrogen salvage system is most effective when the risk of tissue loss and muscle wasting is greatest could lead to new therapeutics to help people in similar situations.</p>
<p>[<em>Over 140,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140ksignup">Sign up today</a>.]</p>
<p>Another potential application is in human spaceflight, during which crew members experience <a href="https://doi.org/10.33549/physiolres.934550">high rates of muscle atrophy</a> because of a microgravity-induced suppression of muscle protein synthesis. Even the extensive exercise regime that astronauts undertake to offset this is insufficient. A microbiome-based countermeasure that facilitates muscle protein synthesis similar to the process we have observed in hibernators may be worth investigating.</p>
<p>These applications, though theoretically possible, are a long way from delivery. But studies in the 1990s demonstrated that humans are capable of <a href="https://doi.org/10.1097/01.mco.0000196142.72985.d3">recycling small amounts of urea nitrogen with the help of their gut microbes</a>. So the necessary machinery is in place – it just needs to be optimized.</p><img src="https://counter.theconversation.com/content/175610/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hannah V. Carey received funding from the U.S. National Science Foundation for this work.</span></em></p><p class="fine-print"><em><span>Matthew Regan receives funding from the Natural Sciences and Engineering Research Council of Canada and the Canadian Space Agency.</span></em></p>Months not eating or moving don’t result in muscle wasting and loss of function for animals that hibernate. New research found gut microbes help their hosts hold onto and use nitrogen to build proteins.Hannah V. Carey, Professor Emeritus of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-MadisonMatthew Regan, Assistant Professor of Biological Sciences, Université de MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1658102021-08-11T02:56:24Z2021-08-11T02:56:24ZUse it or rapidly lose it: how to keep up strength training in lockdown<figure><img src="https://images.theconversation.com/files/415179/original/file-20210809-15-hmsoqo.jpg?ixlib=rb-1.1.0&rect=41%2C10%2C6837%2C4578&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>If you’re among the millions in lockdown, ask yourself: when was the last time you did some strength training? </p>
<p>Many of us are regularly going for walks or runs during lockdown but, with gyms closed in a lot of places it’s more difficult to lift weights, and we may neglect bodyweight exercises like push-ups.</p>
<p>Unfortunately, when it comes to muscle mass, it’s a case of use it or rapidly lose it.</p>
<h2>Short- and long-term consequences</h2>
<p>Research shows <a href="https://pubmed.ncbi.nlm.nih.gov/15356032/">periods</a> of muscle disuse can lead to staggeringly <a href="https://pubmed.ncbi.nlm.nih.gov/19654872">rapid</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/31688656">significant</a> loss of muscle mass, even in young people.</p>
<p>Beyond the obvious decline in strength and function, loss of lean muscle mass can affect metabolism, increase type 2 diabetes and obesity risk and weaken your bones. In older people, it’s associated with cardiovascular disease, osteoarthritis, cognitive impairment, depression, falls and fractures.</p>
<p>That’s why it’s so crucial to keep up your strength training and maintain muscle mass, even in lockdown. The good news is there is plenty of strength training exercises you can do at home, even without special equipment. </p>
<p>Try as best you can to match your usual strength training routine during this time or, if you don’t have one, begin building it into your day.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman does exercise at home with kids." src="https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415391/original/file-20210810-17-1tk5hs6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Reductions in muscle mass have serious short- and long-term consequences, so keep up the strength training during lockdown.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
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Read more:
<a href="https://theconversation.com/the-muscle-wasting-condition-sarcopenia-is-now-a-recognised-disease-but-we-can-all-protect-ourselves-119458">The muscle-wasting condition 'sarcopenia' is now a recognised disease. But we can all protect ourselves</a>
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</em>
</p>
<hr>
<h2>Young people are not immune to muscle mass loss</h2>
<p>Many think of muscle mass loss as a problem that mostly affects older people, but even people in their early 20s can experience rapid muscle loss under certain conditions.</p>
<p>One <a href="https://diabetes.diabetesjournals.org/content/65/10/2862">study</a> of men in their early 20s found just one week of strict bed rest resulted in an average loss of around 1.4kg in whole-body lean mass. </p>
<p>Another <a href="https://pubmed.ncbi.nlm.nih.gov/19654872/">study</a>, involving young people who had one leg immobilised by knee brace, observed muscle size decreased in the immobilised legs by approximately 5% over two weeks. Strength decreased by 10-20%.</p>
<p>Clearly, lockdowns do not enforce the same degree of muscle disuse as bed rest or immobilisation.</p>
<p>Nonetheless, in <a href="https://www.tandfonline.com/doi/full/10.1080/17461391.2020.1761076">studies</a> where people decreased their usual physical activity levels, it took just two weeks or so for worrying changes in lean mass, insulin sensitivity and function to show up.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man does a push-up with a kid on his back." src="https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415404/original/file-20210810-17-ry0f6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Anything you can do to find ways to maintain activity and reduce sedentary time during lockdowns is likely to limit or prevent significant muscle loss.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Decline can happen in fits and starts</h2>
<p>People in my field of research talk a lot about “sarcopenia”: the age-related loss of muscle mass and function that begins in your 30s and can accelerate as you age. </p>
<p>Traditionally, we’ve thought of sarcopenia as occurring in a largely linear fashion.</p>
<p>However, a newer idea suggests this decline may <a href="https://journals.sagepub.com/doi/full/10.1177/2042018819888824">not be so linear</a> after all. Perhaps it happens in fits and starts, where acute episodes of sedentary behaviour (often due to illness or hospitalisation) result in repeated short but severe declines in muscle mass. Researchers call this a “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276215/">catabolic crisis model</a>”.</p>
<p>According to this idea, muscle mass recovers at the end of each acute episode, but never quite returns to its initial quantity. Over time, an accumulation of episodes results in substantial muscle loss and severely compromised physical function.</p>
<p>Of course, some people may be exercising more than usual during lockdown. That’s great! But <a href="https://www.acpjournals.org/doi/10.7326/M17-0212">sedentary behaviour</a> can easily creep in. One <a href="https://www.tandfonline.com/doi/full/10.1080/02640414.2020.1841396">study</a> of people under lockdown found increases in walking and moderate physical activity were only around 10 minutes per day, whereas sedentary behaviour increased by around 75 minutes per day. </p>
<p>And of <a href="https://bmjopensem.bmj.com/content/7/1/e000960.abstract">64 studies</a> exploring changes in activity related to COVID-19 lockdowns, most observed decreases in physical activity and increases in sedentary behaviour.</p>
<p>Anything you can do to find ways to maintain activity and reduce sedentary time during lockdowns is likely to limit or prevent significant muscle loss.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman does some planking at home on a mat." src="https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=254&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=254&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=254&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=320&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=320&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415406/original/file-20210810-23-dss47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=320&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Anything you can do to find ways to maintain activity and reduce sedentary time during lockdowns is likely to limit or prevent significant muscle loss.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>How to build and maintain muscle at home</h2>
<p>Resistance training is unequivocally the best way to build and strengthen muscle. This is any type of exercise that causes your muscles to contract against an external resistance. </p>
<p>The classic example of resistance training is using a weights machine but there are plenty of resistance exercises you can do at home with little or no equipment, including: </p>
<ul>
<li><p>“equipment-free” strengthening exercises such as push-ups, planks, triceps dips, lunges, squats, calf raises and sit-ups</p></li>
<li><p>exercises using dumbbells or resistance bands if you’ve got them. If you don’t, try lifting bricks, full milk bottles, or any heavy household item</p></li>
<li><p>functional “power” exercises like climbing a flight of stairs as quickly (and safely) as you can or seeing how many times you can get up and sit down in a chair in 30 seconds. Try deadlifts with a heavy item, or pushing a loaded wheelbarrow outside.</p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman does tricep dips at home." src="https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415563/original/file-20210811-22-1o6wiq1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Strengthening exercises such as push-ups, planks, tricep dips, lunges, squats, calf raises and sit-ups can be done at home.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Aim for at least 30 minutes per day of moderate to vigorous activity. Brisk walking, jogging, cycling or swimming is great. However, at least two days a week you should be doing resistance exercises to build and maintain muscle mass.</p>
<p>If time is an issue, try splitting your exercise into short 5-10 minute “snacks” across the day. This “exercise snacking” is a great way to break up long periods of sedentary time during lockdown. </p>
<p>Try to integrate resistance exercises into your daily chores. If you need something from a lower drawer, for example, don’t bend down to get it — do a squat. Do some single-legged squats and calf raises while washing up.</p>
<p>Need a video for guidance? <a href="https://www.youtube.com/watch?v=L8ynxqwHnAc">This</a> one and <a href="https://www.youtube.com/watch?v=06msLl_wMtM">this</a> one are pretty good for younger and fitter people. If you’re older, or just getting into fitness, try <a href="https://www.youtube.com/watch?v=Ev6yE55kYGw">this</a> one or <a href="https://www.nhs.uk/better-health/get-active/home-workout-videos/">this</a> one. </p>
<h2>Start ‘banking’ muscle early in life</h2>
<p>Through regular exercise, children, adolescents and young adults can accumulate and maintain higher amounts of muscle mass. In doing so, they can likely avoid significant loss of independence in older age. </p>
<p>Just like superannuation, we need to start making “muscle deposits” early and often throughout life.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-stay-fit-and-active-at-home-during-the-coronavirus-self-isolation-134044">How to stay fit and active at home during the coronavirus self-isolation</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/165810/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Scott has been a consultant for Pfizer Consumer Healthcare and Abbott Nutrition. He has received competitive research funding from the National Health and Medical Research Council (NHMRC), Medical Research Future Fund (MRFF) and Amgen Australia. He is a Council member of the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR), and Chair of the ANZSSFR Sarcopenia Diagnosis and Management Taskforce.
</span></em></p>Many think of muscle mass loss as a problem that mostly affects older people, but even people in their early 20s can experience rapid muscle loss under certain conditions.David Scott, Associate Professor (Research) and NHMRC Emerging Leadership Fellow, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1593492021-04-22T07:34:51Z2021-04-22T07:34:51ZAlexei Navalny has been on a hunger strike for over 3 weeks. How long can humans survive without food?<p>From time to time, generally when there’s a public case of a hunger strike, people ask me how long a person can survive without food.</p>
<p>The hunger strike <a href="https://www.bloomberg.com/news/articles/2021-04-20/kremlin-foe-navalny-extends-hunger-strike-seeks-own-doctors">generating attention</a> at the moment is that of Russian opposition leader Alexei Navalny. Navalny, who was arrested in January after returning to Russia, began refusing food <a href="https://www.washingtonpost.com/world/europe/russia-navalny-hunger-strike-prison/2021/03/31/750214fc-9234-11eb-aadc-af78701a30ca_story.html">on March 31</a> in protest at not being able to access medical care in prison. This means he’s been fasting now for more than three weeks.</p>
<p>Based on the science of long-term fasting, Navalny could theoretically continue his hunger strike for another number of weeks. But reports suggest he’s experiencing problems with his <a href="https://www.reuters.com/world/europe/jailed-kremlin-critic-navalny-growing-risk-kidney-failure-medics-union-2021-04-17/">kidneys</a>, which may be caused by underlying health issues. He’s now <a href="https://www.theguardian.com/world/2021/apr/19/alexei-navalny-moved-to-hospital-as-fears-grow-for-life-of-putin-critic">in a prison hospital</a>, with concerns circulating he is very ill.</p>
<p>To put the specifics of Navalny’s situation aside, a normal adult human can actually survive a surprisingly long time without food, provided they have an adequate intake of water, which contains some minerals. </p>
<h2>Starvation is a long process</h2>
<p>I advise my undergraduate students to avoid hunger strikes to generate public pressure, because generally it takes too long for health risks to become severe enough to garner the expected attention. </p>
<p>Evolution has prepared us well to starve. It’s conceivable early hunter-gatherers and early farmers endured extended periods without adequate food. We’re also aware of pictures of prisoners of war with a skeletal appearance who were undernourished for months, if not years. </p>
<p>The science is pretty well understood, thanks to a pioneer in this field, <a href="https://thehealthsciencesacademy.org/wp-content/uploads/2015/07/Fuel-Metabolism-in-Starvation_ReviewArticleTIMM2008-9Lazar-1.pdf">George F. Cahill</a>, and his colleagues. In the 1960s Cahill worked with volunteers in fasting experiments of up to 40 days, and established many of the ways our bodies seem to adapt to long periods without food. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/by-jailing-alexei-navalny-the-kremlin-may-turn-him-into-an-even-more-potent-opposition-symbol-154258">By jailing Alexei Navalny, the Kremlin may turn him into an even more potent opposition symbol</a>
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</em>
</p>
<hr>
<p>The main challenge to long-term fasting is our brain. It consumes <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6107421/">20% of our total energy</a>, regardless of mental activity. It also loves glucose, our preferred energy provider when we’re eating normally.</p>
<p>The body’s stores of glucose are fairly limited and run out in less than <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566767/">one day</a> when we stop eating. But your body knows what to do. While you’re sleeping or fasting, your body starts to convert muscle mass into glucose, thereby keeping glucose levels up. </p>
<p>Producing glucose <a href="https://thehealthsciencesacademy.org/wp-content/uploads/2015/07/Fuel-Metabolism-in-Starvation_ReviewArticleTIMM2008-9Lazar-1.pdf">from muscle protein</a> is a good way to keep up glucose in the short term, but you don’t want to lose muscle mass in case you need to be active again.</p>
<figure class="align-center ">
<img alt="An empty plate with a fork." src="https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/396476/original/file-20210422-23-1hnfn93.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">When we don’t eat, our body’s stores of glucose — an important energy provider — run out. So our body draws on other reserves for energy.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Enter fat. Fat is our best energy store. In contrast to glycogen (our stores of glucose in the body), fat doesn’t need water to be stored with it, meaning it gives you far more energy for an equivalent amount. Per gram, fat has more than <a href="https://www1.health.gov.au/internet/publications/publishing.nsf/Content/canteen-mgr-tr1%7Enutrition-energy#">twice the energy content</a> of carbohydrates and protein.</p>
<p>Even a person at a normal weight has about <a href="https://en.wikipedia.org/wiki/Body_fat_percentage">15kg of fat</a> and 6kg of protein in the form of muscle. Almost all the fat is dispensable, but only part of the muscles can be wasted to avoid damage to vital organs. </p>
<p>So fat stores are mobilised during fasting to sustain the body. But they provide limited capacity to generate glucose. To keep your brain happy, your body has two tricks up its sleeve. First, fat is converted into <a href="https://en.wikipedia.org/wiki/Ketone_bodies">ketone bodies</a> — an alternative energy supply to glucose — through a process called ketogenesis.</p>
<p>You can push your body to make ketone bodies by eating a lot of fat and minimal glucose (think ketogenic diets), or by starving. The <a href="https://thehealthsciencesacademy.org/wp-content/uploads/2015/07/Fuel-Metabolism-in-Starvation_ReviewArticleTIMM2008-9Lazar-1.pdf">levels of ketone bodies</a> in blood rise after a couple of hours of fasting, and skyrocket over the next couple of days of fasting. Importantly, your organs prefer them over glucose to generate energy. </p>
<p>The second trick is that your brain starts using ketone bodies as an energy source as well. This is an important trick to minimise the loss of muscle mass, by reducing the demand for glucose. The brain works very well on ketone bodies and there’s no reduction of intellectual capacity.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/chemical-messengers-how-hormones-make-us-feel-hungry-and-full-35545">Chemical messengers: how hormones make us feel hungry and full</a>
</strong>
</em>
</p>
<hr>
<p>In summary, the body has some nifty ways of using muscle mass and fat to produce the energy we need, when it’s not coming directly from glucose. And we can usually survive until these alternate supplies are depleted. </p>
<h2>So, how long?</h2>
<p>A normal person might last for almost three months without eating if resting; <a href="https://thehealthsciencesacademy.org/wp-content/uploads/2015/07/Fuel-Metabolism-in-Starvation_ReviewArticleTIMM2008-9Lazar-1.pdf">two months</a> is considered a safe bet. </p>
<p>An obese person could take much longer to starve, perhaps 6-12 months, because of the considerably larger fat mass their body can draw on for energy supplies. However, loss of muscle mass could impair mobility, heart and kidney function.</p>
<p>For a person on a hunger strike, the feeling of hunger first increases but then subsides. In response to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/obr.13191">starvation and malnutrition</a>, a person is likely to experience chronic fatigue, and a range of negative effects on their mood.</p>
<p>However, not drinking any <a href="https://pubmed.ncbi.nlm.nih.gov/32575998/">water</a> is much more dangerous than abstaining from food. It will cause serious health problems and death a lot more quickly.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-the-chemical-agent-that-was-reportedly-used-to-poison-russian-politician-alexei-navalny-145013">What is the chemical agent that was reportedly used to poison Russian politician Alexei Navalny?</a>
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<img src="https://counter.theconversation.com/content/159349/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stefan Broer has received funding from the Australian Research Council (ARC), the National Health and Medical Research Council (NHMRC) for his work on nutrition and proteins. </span></em></p>The average person is likely to be able to survive on a hunger strike for two months, provided they are drinking water. Here’s how the human body can manage for so long without food.Stefan Broer, Head of molecular nutrition group, College of Medicine, Biology and Environment, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1586642021-04-15T15:04:37Z2021-04-15T15:04:37ZSpaceX: will the average person need to exercise during a commercial spaceflight?<figure><img src="https://images.theconversation.com/files/395232/original/file-20210415-18-zuix2s.jpg?ixlib=rb-1.1.0&rect=0%2C38%2C6390%2C4550&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A capsular spacecraft, similar to this, will bring Crew Dragon into space.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/new-commercial-space-capsule-orbiting-planet-1543075538">3Dsculptor/ Shutterstock</a></span></figcaption></figure><p>This year, Elon Musk’s SpaceX plans to launch the <a href="https://inspiration4.com/">first private space mission into orbit</a> with no professional astronauts. Billionaire entrepreneur <a href="https://www.space.com/spacex-unveils-inspiration4-all-private-spaceflight">Jared Isaacman</a>, who chartered the trip and will command the mission, will spend two to four days orbiting Earth in the <a href="https://www.spacex.com/vehicles/dragon/">SpaceX Crew Dragon capsule</a>, alongside <a href="https://www.space.com/inspiration4-spacex-mission-jared-isaacman">three other people</a>. </p>
<p>While Crew Dragon’s short mission is unlikely to have much of an effect on the health of the passengers, these capsules will soon be going on much longer trips, which could have a <a href="https://www.nasa.gov/hrp/bodyinspace">large effect on a person’s health</a>. Space missions decrease astronauts’ bone density by 1%-1.5% per month and weaken movement and postural muscles. Even the heart gets smaller, as it doesn’t have to pump against gravity in space. When these changes take place can vary a lot depending on what exercises are done and how often. But if no exercise is done, these changes will start from 14 days. This is why professional astronauts use exercise equipment in space to keep their muscles strong.</p>
<p>But capsular spacecraft, such as Crew Dragon and Nasa’s Orion – which will take people to the Moon and Mars – will not have the space for large exercise equipment, so passengers will be limited in what they can do. It’s uncertain what effect this may have on the average person’s physical health during space flight, which is what Northumbria’s <a href="http://aerospacemed.rehab/systematic-review-group">Aerospace Medicine Systematic Review Group</a> is helping answer.</p>
<h2>Space to move</h2>
<p>The International Space Station (ISS) has around <a href="https://theconversation.com/curious-kids-how-big-is-the-international-space-station-121442">932m³ of space</a> – around the volume of a Boeing 747. About two-thirds of this space is used for storage and equipment such as <a href="https://www.theverge.com/2017/8/29/16217348/nasa-iss-how-do-astronauts-exercise-in-space">exercise devices</a>, including a treadmill, a bike and a machine built for resistance exercise. </p>
<p>The ISS life support system – which maintains a healthy environment for humans by controlling oxygen, heat and moisture levels in the cabin – is also designed to allow astronauts to exercise for two and a half hours a day, six days a week, without too much heat or carbon dioxide building up.</p>
<p>Orion and Crew Dragon both have around nine cubic meters of living space with around five of these probably usable for exercise. It would be like going on a four-day trip with three friends in a very small campervan without being able to leave the cabin and move around much.</p>
<p>Space station exercise equipment is far too big and heavy for a capsular spacecraft. It’s expected there will only be room for one exercise device in a capsular spacecraft, and this device would need to be about the size of a shoebox and no heavier than 10.6kg. A flywheel exercise device could be used to fit onboard the Orion spacecraft. This is a disc-based device that provides constant resistance during a wide variety of exercises – like a rowing machine.</p>
<p>To exercise as much as ISS astronauts, passengers on capsular spacecraft would probably have to split exercise into several sessions per person daily. This could take up as much as 18 hours per day for the whole crew to exercise if only one device is available. Small bouts of exercise would also ensure filtration systems can scrub additional carbon dioxide, moisture and heat from exercise.</p>
<figure class="align-center ">
<img alt="Astronaut Karen Nyberg exercises using the Advance Resistive Exercise Device to prevent bone mass loss while in space." src="https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395230/original/file-20210415-23-qi8r6f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Astronauts exercise to prevent loss of bone density and muscle while in space.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/nasamarshall/11470308796/">NASA's Marshall Space Flight Center Follow/ Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
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</figure>
<p>But exercise might not always be feasible depending on the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0094576520301119">volume and mass</a> that capsular spacecraft can carry.</p>
<h2>Not exercising</h2>
<p>But what if passengers didn’t exercise at all? To understand what the effects might be, we need to look at bed-rest studies. Constant bed rest is a good way of simulating the effects of spaceflight without having to leave Earth. Strict bed rest also causes similar deconditioning (the decline of physical function) as spaceflight. </p>
<p><a href="https://www.frontiersin.org/articles/10.3389/fphys.2019.01046/full">Research shows</a> that moderate muscle wasting takes about seven days to occur in space if no exercise is performed. So for Crew Dragon passengers, doing no exercise during their two-to-four-day mission will probably only result in a small amount of muscle wasting, as your body needs some level of stress almost every day to maintain good function. And any muscle wasting that occurs will be easy to regain when they return to Earth, simply by being back in normal gravity, holding themselves up and doing their normal daily activities.</p>
<p>But on future longer missions, such as a five-day transit to the Moon – and especially a Mars transit that could take 200 or more days – exercise will be vital. After seven days in space, muscle power, volume and endurance decline. Around 14 days in space, muscles’ ability to work and recover declines. Large changes, such as difficulty standing, begin by 28-35 days without exercise.</p>
<p>Even though a Moon trip is still under seven days, the reduced gravity on the Moon (one-sixth that of Earth’s gravity) is <a href="https://pubmed.ncbi.nlm.nih.gov/28860998/">unlikely to be enough</a> to help the human body stay fit for the return trip. So a round-trip Moon journey will require crew to exercise in order to safely return to Earth. If a lunar stay is more than a few days, astronauts will definitely need exercise to keep their muscles strong and healthy. But these types of missions are likely to remain for professional astronauts only for now.</p>
<p>It’s not yet clear what future exercise devices and protocol will be available for people who spend longer periods in capsular spacecraft. Our research group is investigating which exercises may be most effective at protecting against physical changes while in space. Larger <a href="https://www.lockheedmartin.com/content/dam/lockheed-martin/eo/photo/webt/Orion-Spacecraft-as-a-Key-Element-to-Deep-Space.pdf">habitat modules</a> may also be attached to capsular spacecraft on longer deep-space missions to make exercise easier.</p>
<p>Passengers on commercial spaceflights may also experience <a href="https://humanresearchroadmap.nasa.gov/Evidence/medicalConditions/Space_Motion_Sickness_(Space_Adaptation).pdf">space adaptation syndrome</a>, which causes motion sickness. It affects 60%-80% of space travellers during the first two to three days of their mission. Stuffy sinuses and headaches from fluids shifting upwards, and back pain as their spines lengthen from lack of gravity, may also happen. But these problems will be minor on a short mission like Crew Dragon’s and clear up either during the mission or after returning to Earth.</p>
<p>Hopefully, over time, missions like Crew Dragon’s will become longer, more common and cheaper. But as space travel becomes more viable and missions become longer, it will be important to ensure passengers can exercise properly to avoid any negative effects on their health.</p><img src="https://counter.theconversation.com/content/158664/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Winnard receives funding from the European Space Agency, LUNEX University and the Aerospace Medical Association. </span></em></p><p class="fine-print"><em><span>Jonathan Michael Laws receives funding from the European Space Agency, Luxembourg Institute of Research in Orthopedics, Sports Medicine and Science (LIROMS) and the Aerospace Medical Association.
</span></em></p><p class="fine-print"><em><span>Nick Caplan receives funding from the European Space Agency and the UK Space Agency/STFC.</span></em></p><p class="fine-print"><em><span>Claire Bruce-Martin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Exercise is important for astronauts to prevent weak muscles.Andrew Winnard, Lead for the Aerospace Medicine Systematic Review Group and Lecturer, Northumbria University, NewcastleClaire Bruce-Martin, Senior Lecturer, Sport, Exercise and Rehabilitation, Northumbria University, NewcastleJonathan Michael Laws, PhD researcher, Space Medicine, Northumbria University, NewcastleNick Caplan, Professor of Aerospace Medicine and Rehabilitation, Northumbria University, NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1313742021-02-03T13:10:34Z2021-02-03T13:10:34ZLoss of muscle mass among elderly can lead to falls, and staying put during the pandemic doesn’t help<figure><img src="https://images.theconversation.com/files/381229/original/file-20210128-23-1855e7c.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C8169%2C5499&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Falls are the No. 1 cause of accidental death among people 65 and older. A loss of muscle mass contributes. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/helpless-retired-woman-with-blonde-hair-sitting-on-royalty-free-image/1161018416?adppopup=true">Real People Group via Getty Images</a></span></figcaption></figure><p>Older adults are <a href="https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/older-adults.html">at much higher risk</a> of death from COVID-19 than their younger counterparts, but many also face another, less recognized health risk associated with the pandemic: <a href="https://doi.org/10.1016/j.jamda.2011.01.003">loss of muscle mass</a>. This loss is one of the primary reasons for falls – the <a href="https://www.cdc.gov/mmwr/volumes/67/wr/mm6718a1.htm">No. 1 cause</a> of accidental death in those 65 and older.</p>
<p>Also known as sarcopenia – from the Greek “sarco,” meaning flesh, and “penia” referring to deficiency or poverty – loss of muscle mass and strength is common among elders, but starts <a href="https://www.aginginmotion.org/about-the-issue/">as early as our 30’s</a>. Poor diet is a risk factor for sarcopenia; so is physical inactivity. Now, with gyms closed and community centers on lockdown, many older people are arguably more sedentary than ever.</p>
<p><a href="https://nutrition.tufts.edu/profile/faculty/roger-fielding">I lead a team of scientists</a> who study the role of physical activity and diet on sarcopenia at the <a href="https://hnrca.tufts.edu">Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University</a>. Every day I am struck by how this condition affects patients. Not only can <a href="https://doi.org/10.1016/j.jamda.2011.01.003">sarcopenia lead to falls</a>; it can also lead to social isolation resulting from the falls, which can have a cascade of negative health consequences on older people. This is yet another example of the devastation caused by the pandemic. </p>
<figure class="align-center ">
<img alt="A woman lifting weights." src="https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/381803/original/file-20210201-15-1ruvkv9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Studies suggest women are prone to more muscle mass loss than men.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/mature-woman-weight-training-in-gym-royalty-free-image/1163686644?adppopup=true">Jamie Grill via Getty Images</a></span>
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<h2>Of muscles and men, and women</h2>
<p>Sarcopenia is not unique to the time of coronavirus, however. As people age, they will lose muscle mass and strength as part of the natural aging process. When people lose muscle mass, it is replaced by fat and fibrous tissue, resulting in muscles looking like marbled steak. The rate of decline varies, with inactive seniors losing more than others. Researchers estimate that, generally, those between ages 60 and 70 <a href="https://www.health.harvard.edu/staying-healthy/preserve-your-muscle-mass#:%7E:text=Age%2Drelated%20muscle%20loss%2C%20called,muscle%20mass%20during%20their%20lifetimes.">have lost 12% of their muscle mass</a>, with those over 80 having lost 30%. </p>
<p>This loss is not just about sagging skin and flabby arms. Loss of muscle mass leads to varying degrees of inability to perform daily activities, like walking. That can begin a cascade of effects, including slower movement and loss of balance, which also restrict a person’s ability to live fully. In addition, <a href="https://doi.org/10.2147/DMSO.S186600">sarcopenia is associated with </a> inflammation, insulin resistance, a drop in testosterone and estrogen levels, and chronic diseases, such as Type 2 diabetes, heart disease and pulmonary disease. </p>
<h2>The role of exercise and diet</h2>
<p>There are no FDA-approved medications to treat sarcopenia, but <a href="https://doi.org/10.4235/agmr.19.0028">candidate therapies are in the pipeline</a>. In the meantime, a wealth of evidence highlights the positive benefits of physical activity and proper nutrition to prevent and treat sarcopenia. All types of exercise offer benefits, but resistance or strength training works best. </p>
<figure class="align-center ">
<img alt="A man lifting weights." src="https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/381804/original/file-20210201-19-170ig91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Weight training, along with low-impact aerobic activities and a good diet, can help stave off sarcopenia.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/senior-man-weight-training-in-gym-royalty-free-image/200380506-001?adppopup=true">Barry Austin via Getty Images</a></span>
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<p>One study of older adults showed walking and low-intensity strength training <a href="https://doi.org/10.1371/journal.pone.0182155">reduced the risk of major mobility disability</a> when compared with a health education control group over the course of two years. Previously sedentary people – those reporting fewer than 20 minutes of physical activity per week – saw the greatest benefits. By adding at least 48 minutes of physical activity to their weekly routine, they experienced the biggest reduction in disability risk.</p>
<p>Other observational studies suggest diet can also <a href="https://doi.org/10.1093/gerona/gly201">influence age-associated declines</a> in muscle mass and strength. Protein intake may play a role. In one study, older adults taking in the least amount of protein had inflammation scores <a href="https://doi.org/10.1093/cdn/nzz019">twice as high</a> as participants who consumed the most protein. </p>
<p>Another study found higher protein intake (92.2 grams a day) was associated with a 30% lower risk of increasing weakness compared with people taking in only 64.4 grams daily. But further research is needed to clearly establish the role of protein intake and other nutrients in sarcopenia.</p>
<p>As damaging as the effects of sarcopenia can be, there still is no universally agreed upon clinical test for it. However, <a href="https://doi.org/10.1007/s12603-009-0204-9">imaging techniques exist</a> to measure muscle mass, along with tools to assess strength and physical functioning. Measures of muscle strength are closely associated with usual walking speed and the time it takes to rise from a chair. </p>
<p>Another issue is that despite all the studies, many clinicians remain unaware of this syndrome. Maybe one of the best ways to combat this condition is to educate them about sarcopenia – and just as critically, provide them with practical guidelines about appropriate physical activity and proper nutrition for their patients. Seniors, and their loved ones, deserve to know the risks.</p><img src="https://counter.theconversation.com/content/131374/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roger Fielding consults for Merck, Pfizer, Eli Lilly, Axcella Health, Segterra, Amazentis, Nestle, Biophytis, Astellas, Juvicell, and Cytokinetic. He owns shares in Axcella Health, Segterra, and Juvicell. He receives funding from USDA, NIH, DOD, Dairy Research Institute, Unilever, Nestle, Regeneron, Astellas, Lonza, Axcella, Biophytis. </span></em></p>Loss of muscle mass is a growing concern for the tens of millions of older Americans. It leads to falls and increased isolation, already a huge problem during coronavirus.Roger Fielding, Lab Director and Senior Scientist, Tufts UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1492312020-12-28T13:35:57Z2020-12-28T13:35:57ZWhether slow or fast, here’s how your metabolism influences how many calories you burn each day<figure><img src="https://images.theconversation.com/files/376587/original/file-20201223-15-3whpcv.jpg?ixlib=rb-1.1.0&rect=194%2C72%2C5197%2C3338&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Why does it seem like some people can eat anything and not gain a pound while others are the opposite?</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/mother-looking-at-son-royalty-free-image/535080170">Heide Benser/The Image Bank via Getty Images</a></span></figcaption></figure><p>It’s a common dieter’s lament: “Ugh, my metabolism is so slow, I’m never going to lose any weight.” </p>
<p>When people talk about a fast or slow metabolism, what they’re really getting at is how many calories their body burns as they go about their day. The idea is that someone with a slow metabolism just won’t use up the same amount of energy to do the same task as does someone with a fast metabolism.</p>
<p>But does the speed of metabolism really vary all that much from person to person? I’m a nutrition scholar who focuses on the biological, environmental and socioeconomic factors that influence body composition. This question is trickier than it might first seem – and whatever the current speed of your metabolism, there are things that will nudge it into lower or higher gears.</p>
<h2>Your body’s energy needs</h2>
<p>Metabolism is a biological term that refers to all the chemical reactions needed to maintain life in an organism. Your metabolism accomplishes three main jobs: <a href="https://www.ncbi.nlm.nih.gov/books/NBK26882/">converting food into energy</a>; breaking down food into its building blocks for protein, lipid, nucleic acid and some carbohydrate; and eliminating nitrogen wastes. </p>
<p>If you’re agonizing over the speed of your metabolism, you’re probably focused on how much energy you’re getting from the foods you eat and how much your body is using. The <a href="https://www.ncbi.nlm.nih.gov/books/NBK218769/">energy value of a food</a> is measured in calories.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="older couple eat energy bars on a bike ride" src="https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/376476/original/file-20201222-23-q2kzbq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Metabolism can be a way to think about the energy you take in and the energy you expend.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/african-american-couple-with-bikes-eating-snack-royalty-free-image/521419354">kali9/E+ via Getty Images</a></span>
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<p>Your caloric needs can be divided into two categories. </p>
<p>Basal metabolic rate is the minimum amount of <a href="https://doi.org/10.1079/phn2005801">calories required for basic functions at rest</a>. Resting energy expenditure is the amount of calories you body use while resting or sleeping – <a href="https://doi.org/10.4103/ijem.IJEM_484_16">about 60%-65% of your total energy expenditure</a>. It doesn’t take into account the calories you’d need to power everything else you do – moving around, or activity energy expenditure (25%-30%), thinking, even digesting food (5%-10%). So your total energy expenditure combines the two: your resting energy expenditure plus your energy expenditures for other activities.</p>
<h2>Coming up with a number</h2>
<p>The <a href="https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/appendix-2/">estimated daily caloric intake needs</a> for an adult woman of 126 pounds (57 kilograms) range from 1,600 to 2,400 calories per day. For a man of 154 pounds (70 kilograms), daily calorie needs can range from about 2,000 to 3,000 calories per day. That’s about 11-14 calories per pound of body weight (25-30 calories per kilogram).</p>
<p>In contrast, <a href="https://www.ncbi.nlm.nih.gov/books/NBK560758/">infants burn about 50 calories per pound of weight per day</a> (120 calories per kilogram). This requirement continuously decreases as the child ages. So infants have the highest metabolism of all. This extra calorie requirement is necessary <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2642618/">for growth</a>.</p>
<p>So if two women of the same weight can have caloric needs that vary by as much as 30%, does that mean the woman whose body uses up more calories has a faster metabolism than the woman whose body uses fewer calories? Not necessarily. One woman might spend more of her day physically active and thus need more energy to power her walking commute and after-work kickboxing class, for instance. </p>
<p>Beyond those rough guideline ranges, there are many ways to estimate resting and total energy expenditure if you want to figure out your body’s specific calorie needs. One common and easy method is to use predictive formulas <a href="https://doi.org/10.1093/ajcn/51.2.241">such as the Mifflin-St. Jeor</a> or <a href="https://pubmed.ncbi.nlm.nih.gov/11817239/">Harris-Benedict</a> equations which are <a href="https://doi.org/10.1016/j.nutres.2007.01.016">based on your age, height, weight and gender</a> to figure out how much energy your body needs just to be alive. To calculate total energy expenditure, you also need to add the activity factor. </p>
<p><a href="https://www.indirectcalorimetry.net/2017/10/04/understanding-indirect-calorimetry/">Indirect calorimetry</a> is another way to estimate metabolic rate. Energy expenditure is calculated by measuring the amount of oxygen used, and carbon dioxide released by the body. Your body relies on oxygen to perform all its jobs of metabolism. For every liter of oxygen you use, you <a href="https://icuprimaryprep.files.wordpress.com/2012/05/nutrition-and-metabolism.pdf">use about 4.82 calories of energy</a> from glycogen or fat. Respiratory indirect calorimetry is typically done at a doctor’s office, though small, portable, more affordable devices are increasingly being brought to market. </p>
<h2>Factors that influence metabolic rate</h2>
<p>Metabolic rate and calorie requirements vary from person to person <a href="https://www.ncbi.nlm.nih.gov/books/NBK221834/">depending on factors</a> such as genetics, gender, age, body composition and amount of exercise you do. </p>
<p>Health status and certain medical conditions may also influence metabolism. For example, one regulator of metabolism is the thyroid gland, located at the front of the neck just below the Adam’s apple. <a href="https://doi.org/10.1152/physrev.00030.2013">The more thyroxin a person’s thyroid gland produces</a>, the higher that person’s basal metabolic rate will be.</p>
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<p>Having a fever can also affect a person’s basal metabolic rate. For <a href="https://www.ncbi.nlm.nih.gov/books/NBK331/">each increase of 0.9 degrees Fahrenheit (0.5 C)</a> in a person’s internal body temperature, their basal metabolic rate increases by approximately 7%.</p>
<p>Other medical conditions that influence basal metabolic rate can include muscle wasting (atrophy), <a href="https://derangedphysiology.com/main/required-reading/endocrinology-metabolism-and-nutrition/Chapter%20318/physiological-adaptation-prolonged-starvation">prolonged starvation</a>, low oxygen levels in the body (hypoxia), muscular disorders, depression and <a href="https://doi.org/10.2337/diabetes.48.8.1607">diabetes</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman with grey hair working out with small weights" src="https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/376477/original/file-20201222-50514-1lwoh30.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It takes more energy to maintain muscle than fat in your body.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/mature-mexican-woman-working-out-royalty-free-image/1168227653">adamkaz/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>Another important factor is body composition. For example, an overweight woman with a body composition of 40% body fat and 75 pounds of muscle mass will burn fewer calories while resting than a woman with 30% body fat and 110 pounds of muscle mass; <a href="https://doi.org/10.1038/oby.2011.256">muscle tissue is more metabolically active than fat tissue</a> in the body. </p>
<p>This is also why <a href="https://doi.org/10.1016/j.arr.2009.08.002">basal metabolic rate decreases with age</a>. As people get older, they typically lose muscle mass and gain fat tissue – which equates to a <a href="https://doi.org/10.3143/geriatrics.30.572">decrease in basal metabolic rate of approximately 1% to 2% per decade</a>.</p>
<p>If you really want to give your metabolism a jolt, the easiest way is to bump up your muscle mass and activity level. By increasing muscle mass, you’ll also increase the base number of calories needed <a href="https://doi.org/10.1172/JCI114857">to maintain those muscles</a>. Instead of complaining about a slow metabolism, you can try to turn it up to be at least a bit quicker.</p>
<p><em>This article was updated to include metric measurements for weights.</em></p><img src="https://counter.theconversation.com/content/149231/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terezie Tolar-Peterson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There are some factors you can’t change about your metabolism. But there are things you can do to influence how much energy your body uses over the course of the day.Terezie Tolar-Peterson, Associate Professor of Food Science, Nutrition & Health Promotion, Mississippi State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1458612020-10-15T11:37:41Z2020-10-15T11:37:41ZHow strong your grip is says a lot about your health<figure><img src="https://images.theconversation.com/files/363661/original/file-20201015-21-1nsei9w.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7360%2C4912&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Grip strength declines with many health conditions.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hand-holding-nautical-rope-close-symbol-362181254">Lars Hallstrom/ Shutterstock</a></span></figcaption></figure><p>The human hand is remarkable. Not only does it allow us to throw, grab, climb and pick things up, it can also be a measure of health. Using hand-grip strength – which assesses the amount of force a person can generate with their grip – researchers can not only understand a <a href="https://www.researchgate.net/profile/Anneli_Peolsson/publication/223280085_Reference_values_for_adult_grip_strength_measured_with_a_Jamar_dynamometer_A_descriptive_meta-analysis/links/5aa8cd40aca2726f41b17cc4/Reference-values-for-adult-grip-strength-measured-with-a-Jamar-dynamometer-A-descriptive-meta-analysis.pdf">person’s strength</a>, they can also know the rate a person is ageing and even <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6778477/">diagnose certain health conditions</a>, such as heart disease and cancer. </p>
<p>Grip strength is typically tested using a dynamometer, which a person grasps the same way they’d hold a glass, with the elbow tucked into the side and positioned at right angles. The instrument is then squeezed for about five seconds. The test is performed on both hands, usually three squeezes on each hand, and then the average is taken. Men aged 20-30 typically have the <a href="https://www.jospt.org/doi/abs/10.2519/jospt.2018.7851?journalCode=jospt">greatest strength</a>, while women over 75 have the lowest. In people aged 20-29 years old, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3101655/">average grip strength</a> is 46kg for men and 29kg for women. This decreases to 39kg and 23.5kg by the time a person reaches 60-69 years of age.</p>
<p>Research shows that having a grip strength that was lower than average compared to people of the same gender and age range was associated with <a href="https://www.bhf.org.uk/what-we-do/news-from-the-bhf/news-archive/2018/march/weak-handshake-could-be-sign-of-a-failing-heart">risk of heart failure</a>, where lower strength indicated <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0193124">detrimental changes</a> in the heart’s structure and function. Similarly, research has shown weaker grip strength is a <a href="https://heart.bmj.com/content/105/11/834">strong predictor</a> of <a href="https://www.bmj.com/content/361/bmj.k1651">cardiac death</a>, death from any cause, and hospital admission for heart failure. </p>
<p>Grip strength may also be useful for predicting survival from cancer. Though survival is based on other factors, such as cancer type and time of diagnosis, one study found patients were more likely to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7113515/">survive non-small-cell lung cancer</a> the greater their grip strength was.</p>
<p>Being diagnosed with colorectal, prostate or lung cancer in men, and breast and lung cancer in women are all associated with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5939721/">five-kilogram reduction in grip strength</a> in people aged 60-69. This decrease in grip strength was also associated with a higher likelihood of death from colorectal cancer in men and breast cancer in women.</p>
<p>Obesity is also associated with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3041473/">weaker grip</a> in later life. The presence of fat in and around muscle <a href="https://jeb.biologists.org/content/jexbio/221/13/jeb163840.full.pdf">reduces muscle efficiency</a>. Recent work looking at <a href="https://www.tandfonline.com/doi/full/10.1080/07853890.2020.1815078">diabetes and grip strength</a> has also shown that people who develop type 2 diabetes have a weaker grip strength. This is probably caused by the presence of fat in the muscles making them less efficient at doing their job – subsequently increasing inactivity and worsening muscular decline. </p>
<figure class="align-center ">
<img alt="Older woman gripping a dynamometer to test her grip strength." src="https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363662/original/file-20201015-21-gm7ayg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ageing also reduces our grip strength.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hand-dynamometer-grip-strength-test-1645373038">Microgen/ Shutterstock</a></span>
</figcaption>
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<p>Grip strength declines with age. Research shows that as the body <a href="https://physoc.onlinelibrary.wiley.com/doi/full/10.1113/JP275520">loses muscle mass</a> as we age, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6700453/">grip strength decreases</a>. Ageing causes a decline in muscle mass (and function), at a <a href="https://www.sciencedirect.com/science/article/pii/S156816371830134X">rate</a> of 1% a year from middle age. This can result in a loss of up to 50% of muscle mass by 80-90 years of age.</p>
<p>But ageing progresses at different rates in different people. This means that grip strength could decrease from age-related changes in the nervous system where signals do not <a href="https://www.ncbi.nlm.nih.gov/books/NBK3873/">travel as fast</a>, or from muscle loss in the arms. Another study has shown that reduced grip strength in older adults is associated with <a href="https://pubmed.ncbi.nlm.nih.gov/31322562/">lower cognitive function</a>. </p>
<h2>Muscle loss</h2>
<p>Loss of muscle tissue occurs all over the body when we develop certain health conditions and when we age. However, it can be difficult to measure strength in many places, which is why the hands are so useful. Their ability to produce both fine and force movements makes them a good proxy for overall health.</p>
<p>With disease (including heart disease, diabetes and cancer), our muscles’ ability to contract to generate force and their ability to function and move is reduced. This results from one or a combination of factors, such as reduced function of the heart to enable movement or prolonged movement, less efficiency in muscles, fatigue or muscle wasting. Having lower muscle function also results in loss of muscle tissue – and this tissue loss subsequently also leads to decreased muscle strength and the inability to do as much. Certain health conditions might also cause fatigue, which also makes us less likely to move and exercise, causing a cycle of further muscle loss and decline in strength.</p>
<p>Cancer, in particular, can limit how well our digestive system works, making it difficult to consume food and <a href="https://www.gastrojournal.org/article/S0016-5085(07)00575-6/fulltext">reducing appetite</a>. The foods we eat – in particular protein – are especially important for maintaining muscle mass and strength. Without proper food to fuel us and give us energy, the body must draw on its internal reserves to generate energy. One of the main ways it does this is to burn tissue that isn’t being used – and muscle is a favourite fuel for this situation. Loss of body mass reduces the body’s natural stores, and potentially its ability to sustain prolonged chronic illness.</p>
<p>One of the key things people can do to maintain health and improve – or at the very least maintain muscle strength – is to exercise. The body has a “use it or lose it” approach to tissues, with muscles being broken down if not used. For instance, it’s well known that getting patients <a href="https://pubmed.ncbi.nlm.nih.gov/16813627/">walking</a> after surgery prevents loss of muscle and bone and reduces their <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6219981/">length of stay</a> in hospital. </p>
<p>Either way, a strong handshake may offer more information about you than you may realise.</p><img src="https://counter.theconversation.com/content/145861/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>Heart disease, cancer and diabetes all cause weaker hand grip strength.Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1478822020-10-14T12:41:54Z2020-10-14T12:41:54ZMuscle loss can cause a range of health problems as we age – but it can be prevented<figure><img src="https://images.theconversation.com/files/363375/original/file-20201014-15-1jqvjki.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Muscle loss might be an inevitable part of ageing, but exercise can slow this process down.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-four-smiling-senior-women-toning-367740032">belushi/ Shutterstock</a></span></figcaption></figure><p>Here’s a sobering fact: you can lose up to <a href="https://www.jns-journal.com/article/0022-510X(88)90132-3/pdf">40% of your muscle mass</a> between your 20s and your 80s. That might sound outlandish, but it’s a natural part of ageing. Known as sarcopenia, this is the gradual loss of muscle mass that occurs as we age. Although we can start losing muscle from our 20s, this loss really speeds up once we hit our 60s. At the same time that sarcopenia causes loss of muscle mass, we simultaneously gain fat mass, and see a big drop in strength too. All of this can have a big impact on how well an older person moves.</p>
<p>Muscle mass plays a huge role in our health. So much so that sarcopenia and sarcopenic obesity (the combination of low muscle mass and excess fat), and dynapenia (the loss of muscle strength) are associated with a surprisingly wide <a href="https://link.springer.com/article/10.1007/s11357-020-00272-3">range of health conditions</a>, from heart disease and diabetes to frailty and dementia.</p>
<p>In fact, in people who already have heart disease, those with the <a href="https://www.sciencedirect.com/science/article/pii/S0735109712025223?">highest levels of muscle mass</a> seem to have the best chance of living longer. On the other hand, people with the lowest amounts of muscle seem to be at the <a href="https://www.nature.com/articles/s41366-020-0613-8">greatest risk of dying prematurely</a> from all causes. This tells us that muscle might play a protective role in heart health. Why this happens, we don’t yet know – but it may have something to do with chemical messengers (myokines) <a href="https://www.nature.com/articles/nrendo.2012.49">produced by healthy muscles</a>, which can help reduce inflammation throughout the body.</p>
<p>Another major benefit of having healthy muscles is that they help protect us from diabetes. When we eat and digest carbohydrates – such as potatoes, bread or rice – sugar enters our bloodstream, of which a lot is sent to our muscles. Our muscles use this sugar for energy, or store it as glycogen in order to maintain stable blood sugar levels. This process is an important part of blood sugar control and helps explain why people with less muscle are <a href="https://www.mja.com.au/journal/2016/205/7/sarcopenia-potential-cause-and-consequence-type-2-diabetes-australias-ageing">more likely to develop diabetes</a>.</p>
<p>In older people, low levels of muscle are also linked with a <a href="https://www.geriatric.theclinics.com/article/S0749-0690(15)00029-4/fulltext">greater frailty</a>, weakness, and being less able to carry out normal daily activities. This means people can have trouble with regular tasks such as getting out of bed, standing up from chairs, climbing the stairs or carrying groceries. All of this can make living independently a lot more difficult. Difficulty moving can also mean people end up moving even less which speeds up muscle loss. </p>
<p>People with sarcopenia who lead sedentary lives are also at <a href="https://linkinghub.elsevier.com/retrieve/pii/S1094-6950(09)00270-4">greater risk of osteoporosis</a>. This is because active muscles send signals to bones that help them stay strong. The drop in strength from sarcopenia means people may be more prone to falls and bone fractures. Again, this fear of falling may make some people more sedentary, which may <a href="http://www.tandfonline.com/doi/full/10.1080/01612840.2016.1263695">reduce quality of life</a> and put them at a greater risk of depression.</p>
<p>Although sarcopenia is a natural part of ageing, muscle loss is largely accelerated by inactivity. As we get older, we tend to move less. But exercise is one of the key signals that our body needs to <a href="https://journals.lww.com/acsm-msse/Fulltext/2007/11000/Mechanical_Muscle_Function,_Morphology,_and_Fiber.14.aspx">keep our muscles strong</a> and healthy. Without that signal our muscles start getting smaller and weaker over time. <a href="https://www.frontiersin.org/articles/10.3389/fphys.2015.00245/full">Eating protein</a> also acts as a signal to grow and maintain muscle. However as we age, we tend to have smaller appetites and <a href="https://pubmed.ncbi.nlm.nih.gov/32059533/">eat less protein</a>, increasing the risk of muscle loss.</p>
<figure class="align-center ">
<img alt="A lunch of salmon, a boiled egg, and edamame." src="https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363377/original/file-20201014-19-1f8s3yn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Protein in your diet can help maintain muscle.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-eating-natural-protein-food-container-1269490528">New Africa/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Lower levels of the hormones testosterone and oestrogen, higher levels of body fat, insulin resistance (where the body doesn’t handle glucose as it should, which can lead to diabetes) and higher levels of inflammation are other reasons why older people lose muscle more easily than younger people. In fact, all of these factors combined lead to something called “<a href="https://journals.lww.com/co-criticalcare/Abstract/2018/04000/Defining_anabolic_resistance__implications_for.11.aspx">anabolic resistance</a>”. This means the body doesn’t respond as well to the signals that normally cause muscles to grow.</p>
<p>If that isn’t enough, current COVID-19 restrictions may be <a href="https://link.springer.com/article/10.1007/s11357-020-00272-3">making muscle loss even more likely</a>. Data from smartphones has shown that people have been <a href="https://www.jmir.org/2020/9/e19992/">more sedentary than usual</a> during lockdown. We also know that people’s <a href="https://www.sciencedirect.com/science/article/pii/S1389945720302136?via%3Dihub">sleep quality has declined</a> and people are probably feeling more stress and anxiety. These factors can also speed up muscle loss by affecting hormones that <a href="https://academic.oup.com/jcem/article/84/10/3515/2660530">increase muscle breakdown</a> and encourage weight gain by <a href="https://www.acpjournals.org/doi/10.7326/0003-4819-141-11-200412070-00008?">affecting appetite hormones</a>, causing people to eat more processed foods that have more calories.</p>
<p>This is called a “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276215/">catabolic crisis</a>” – a brief period of time when conditions come together to make muscle loss much more likely. Another example of a catabolic crisis would be if someone was hospitalised or forced to spend days, or even weeks in bed. COVID-19 could very well create a catabolic crisis for <a href="https://www.journalofinfection.com/article/S0163-4453(20)30116-X/fulltext">many older adults</a> after a lockdown. </p>
<p>Muscle loss can be prevented – or at least slowed – with a few lifestyle changes, namely <a href="https://link.springer.com/article/10.1007%2Fs12603-019-1261-3">exercise</a> and <a href="https://www.frontiersin.org/articles/10.3389/fphys.2015.00245/full">diet</a>. Resistance exercise, such as lifting weights or using elastic resistance bands, helps keep muscles strong and healthy and <a href="https://www.jfrailtyaging.com/all-issues.html?article=780">regular walking can help too</a>. </p>
<p><a href="https://www.frontiersin.org/articles/10.3389/fphys.2015.00245/full">High protein diets</a>, containing foods such as lean meats, fish, eggs and low-fat dairy products can also help to build and maintain more muscle than exercise alone. Getting at least 25-40 grams of protein each meal is especially important. On top of that, widely available supplements including <a href="https://www.karger.com/Article/Abstract/235874">vitamin D</a>, <a href="https://academic.oup.com/ajcn/article/95/2/428/4576792">fish oil</a> and <a href="https://link.springer.com/article/10.1007%2Fs00421-012-2514-6">creatine</a> (a naturally occurring substance found in the muscles which helps them produce energy) may help people hold on to more muscle and improve their quality of life as they age. During this pandemic, when muscle loss is more likely, prioritising regular exercise and a healthy diet can make a big difference to long-term health.</p><img src="https://counter.theconversation.com/content/147882/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span><a href="mailto:c.e.stewart@ljmu.ac.uk">c.e.stewart@ljmu.ac.uk</a> receives funding from BBSRC and Dunhill Medical Trust.</span></em></p><p class="fine-print"><em><span>Richard Kirwan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Without proper care, lockdown measures during the COVID-19 pandemic could worsen muscle loss and long-term health in ageing populations.Richard Kirwan, PhD Researcher Clinical Nutrition and Physiology, Liverpool John Moores UniversityClaire Stewart, Professor of Stem Cell Biology, Liverpool John Moores UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1438752020-09-02T11:18:11Z2020-09-02T11:18:11ZRest days are important for fitness – here’s why, according to science<figure><img src="https://images.theconversation.com/files/356040/original/file-20200902-22-1f44dwm.jpg?ixlib=rb-1.1.0&rect=41%2C0%2C6836%2C4433&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rest days are just as important as your workouts.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/couple-exercising-together-man-woman-sports-1464709727">Jacob Lund/ Shutterstock</a></span></figcaption></figure><p>In 2017, world famous distance runner, Ron Hill, ended his record of <a href="https://www.ronhill.com/blogs/news/ron-ends-record-breaking-run-streak-after-52-years-and-39-days">52 years and 39 days</a> of consecutive running by taking a day’s rest after feeling unwell during one of his runs.</p>
<p>Hill writes in his autobiography that he ran at least one mile a day, and tasked himself with training 13 times per week. His training was conducted without a coach, and was done on a trial and error basis. </p>
<p>Though successful – he even competed twice in the Olympics – there were occasions that he describes the symptoms of over-training. These included sore and heavy legs, increased susceptibility to colds and infections, and weight loss. Though Hill found a training regimen that helped him prepare for competition, he wondered if some of his substandard performances were a consequence of not taking any rest days. </p>
<p>When starting a new fitness regime, we’re often told it’s important to take “rest days” between workouts. The reason many recommend rest days is to allow the body’s muscles to recover from any damage they’ve sustained during workouts, and to allow them to grow. And numerous scientific studies show that rest days do indeed play an important role in helping us maintain good health and fitness. </p>
<p>We usually define rest as a period of time without any training. For most people, this is usually about 24 hours between workouts. However, recovery is different, and could indicate a time span of several minutes to hours (such as taking a short break during training between rounds). Recovery could also indicate the time required to induce some form of <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.872.5387&rep=rep1&type=pdf">physiological adaptation</a>, such as the observed rapid increase in plasma volume, which could improve aerobic fitness. But how necessary are both rest and recovery as part of a training program? </p>
<h2>Take a break</h2>
<p>Most studies indicate that rest and recovery between workouts are both necessary for helping the body adapt and recuperate from one’s last workouts. Exercise requires us to use our body’s energy stores (primarily carbohydrates) and fluids (in producing sweat), so rest and recovery give the body time to replenish these energy stores.</p>
<p>Several studies have shown that the body needs at least 24 hours to fully replace our muscle’s <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3905295/">store of carbohydrates</a>. Maintaining an adequate store of muscle glycogen (glycogen is the body’s store of carbohydrate), is important for training and maintaining stable blood sugar levels.</p>
<p>However, less time is required to recover our fluids. Numerous studies have found it takes only around one to two hours to replace our fluids lost as sweat during exercise. But our bodies still require <a href="https://www.sciencedirect.com/science/article/abs/pii/S0765159704000516">several hours</a> of rest following exercise to maintain hydration due to the continued production of urine.</p>
<p>Training may also damage our body’s tissues. Under some circumstances this damage can be beneficial, but is not an essential part of building muscle. But in order for muscle to recover and improve (known as physiological adaptation) they require <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1995688/">several weeks</a> of cycles of exercise and recovery. </p>
<p>Research shows our bodies require a <a href="https://journals.physiology.org/doi/full/10.1152/ajpendo.00415.2005">longer rest period</a> in order to build muscle tissue (protein synthesis). But given the turnover of protein for muscle, tendon and ligaments is between <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0224745#pone.0224745.ref004">0.4-1.2% a day</a>, this shows there’s a constant exchange of protein in our body related to dietary intake, urinary nitrogen excretion and the added effect of exercise.</p>
<figure class="align-center ">
<img alt="Woman sitting on the floor of gym with water bottle and kettlebell." src="https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/356044/original/file-20200902-20-1gf5wf5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Muscles require a longer rest period.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fitness-workout-gym-exercise-lifestyle-healthy-1420566605">Day Of Victory Studio/ Shutterstock</a></span>
</figcaption>
</figure>
<p>The hours just after the initial workout may actually be most important for making this happen. Researchers reported that a three-hour feeding pattern of whey protein was more effective at <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3650697/">increasing protein synthesis</a> than feeding every 1.5 or six hours over a 12-hour period.</p>
<p>Many other adaptations that occur as a consequence of training (such as increasing the activity of enzymes and glucose transporters, which are key in oxygen consumption and fuel use), require a period in <a href="https://journals.physiology.org/doi/abs/10.1152/ajpregu.1997.272.5.R1620">excess of 12 hours</a> before changes are detected. These changes are important, as when we increase our exercise intensity, we need to use glucose instead of fat to fuel our exercise. </p>
<p>Longer-term adaptations, such as increasing the number of blood vessels in our exercised muscles, or increasing the size of the heart, are a much longer process, requiring months of training and rest to observe any measurable change. Both adaptations are key to increasing our <a href="https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/EP088187">aerobic capacity</a>.</p>
<p>The quality of rest has also been a source of much interest, and sleep deprivation has been used as a tool to examine the effects of disturbed rest on exercise performance and physical and psychological function. A wide-ranging review concluded that disturbed sleep may have a <a href="https://www.researchgate.net/profile/Hugh_Fullagar/publication/266855811_Sleep_and_Athletic_Performance_The_Effects_of_Sleep_Loss_on_Exercise_Performance_and_Physiological_and_Cognitive_Responses_to_Exercise/links/56200c3308ae93a5c9243a18/Sleep-and-Athletic-Performance-The-Effects-of-Sleep-Loss-on-Exercise-Performance-and-Physiological-and-Cognitive-Responses-to-Exercise.pd">detrimental effect</a> on performance, such as a reduced time to exhaustion – but they were clear that sleep deprivation had many negative effects on cognitive function.</p>
<p>Overwhelming evidence also shows rest days are also extremely important for preventing <a href="https://www.tandfonline.com/doi/full/10.1080/02640414.2018.1424498?scroll=top&needAccess=true">overtraining syndrome</a>. Overtraining syndrome can cause fatigue, sleep loss, weight gain, depression – and may even result in decreased performance and may stall progress.</p>
<p>In general, it seems that one day’s rest per week is sound advice and is supported by the <a href="https://link.springer.com/article/10.2165/00007256-199826010-00001">scientific evidence</a>, especially when it comes to repairing tissues, building and adapting skeletal muscle, and restoring fuel reserves. It may also reduce mental stress. Although Hill set world records at distances between 10 and 16 miles, he is an exceptional example – and even admitted that trying to run every single day may have hindered his performance at the two Olympic games. Based on the evidence, taking a rest day seems to be as important for progress and fitness as exercise itself.</p><img src="https://counter.theconversation.com/content/143875/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Derek Ball receives funding from the Orthopaedic Trauma Association, The Royal College of Surgeons Edinburgh and the Chief Scientists Office. </span></em></p>Studies show rest days are important for helping our body recover and adapt in many ways.Derek Ball, Head of Sport Science, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1451252020-08-28T13:29:38Z2020-08-28T13:29:38ZVitamin C could help older adults retain muscle mass – new research<figure><img src="https://images.theconversation.com/files/355325/original/file-20200828-22-98ep13.jpg?ixlib=rb-1.1.0&rect=6%2C6%2C4354%2C2896&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Muscle mass is important for maintaining health and being active during older age. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-couple-workout-gym-people-lift-642402643">Liderina/ Shutterstock</a></span></figcaption></figure><p>As we get older, our skeletal muscle mass, strength and power to move gradually decline, which may lead to a condition called <a href="https://doi.org/10.1093/ageing/afy169">sarcopenia</a>. Sarcopenia affects more than <a href="https://doi.org/10.1093/ageing/afq034">50 million people</a> over the age of 50 years worldwide, and <a href="https://doi.org/10.1017/S0029665119001150">contributes to</a> type 2 diabetes, frailty, physical disability, loss of independence and poor quality of life. So it’s an important condition to prevent during ageing to minimise both personal and societal costs.</p>
<p>Currently there are limited solutions for treating sarcopenia, so early intervention, before symptoms become too severe, is preferable. Most research has focused on the effect of <a href="https://dx.doi.org/10.1093%2Fadvances%2Fnmy065">increasing protein intake</a> to prevent or treat sarcopenia. </p>
<p>But very few studies have actually investigated the importance of dietary vitamin C with loss of skeletal muscle mass and function in middle and older age. <a href="https://doi.org/10.1093/jn/nxaa221">Our new paper</a> shows that the more dietary vitamin C middle-aged and older adults consume, the greater their skeletal muscle mass.</p>
<p>Vitamin C is already known to play an important role in bone health, but may also help us maintain strong muscles. This vitamin is only found in vegetables, potatoes and fruits. </p>
<p>People who don’t consume enough of these in their diet are at risk of vitamin C deficiency, which may cause weakness, tiredness and fragile bones. In extreme cases, it may lead to scurvy. But before this occurs, insufficient dietary vitamin C intake may have other effects on health, including our muscles.</p>
<p>Around <a href="https://doi.org/10.1111/j.1749-6632.1987.tb23776.x">two-thirds</a> of our body’s total vitamin C is found in skeletal muscle. It’s used for making <a href="https://doi.org/10.1093/ajcn/54.6.1147s">carnitine</a>, a crucial substance that provides energy for muscles to function, and <a href="https://doi.org/10.1111/j.1753-4887.1992.tb01271.x">collagen</a>, which is an essential structural component of muscle. </p>
<p>In addition, vitamin C is a strong antioxidant that can help to <a href="https://dx.doi.org/10.1155%2F2012%2F316943">counteract free radical</a> molecules, which increase when we age. Unopposed, these free radicals can contribute to the destruction of muscle cells.</p>
<h2>Skeletal muscle mass</h2>
<p>Our study looked at data collected from over 13,000 men and women in the <a href="https://www.epic-norfolk.org.uk">European Prospective Investigation into Cancer and Nutrition Norfolk cohort</a>, aged 42-82 years. We used <a href="https://tanita.eu/bioelectrical-impedance-analysis/">bioelectrical impedance analysis</a> – which sends small electrical signals through the body to calculate water and fat percentage – to estimate the proportion of skeletal muscle in the body. </p>
<p>Participants also completed a diary of everything they ate and drank over seven days so we could accurately calculate their intake of dietary vitamin C. We grouped people according to their intake of vitamin C, ranging from low to high. </p>
<p>Vitamin C was also measured directly in their blood, providing results less susceptible to potential error in reporting diet. This allowed us to classify people according to whether they had <a href="https://doi.org/10.2903/j.efsa.2013.3418">sufficient vitamin C intake</a>.</p>
<p>Our statistical analysis took into consideration other important factors, including participant’s physical activity, protein and energy intake, which might also have effects on skeletal muscle mass.</p>
<p>We found that the people in our study who consumed the highest amount of vitamin C in their diet had the greatest muscle mass. The biggest difference was seen in women: those women in the highest category of vitamin C consumption had muscle mass 3% greater than those in the lowest category. </p>
<p>These differences are likely to be clinically relevant, especially given that most people are estimated to lose <a href="https://doi.org/10.3389/fphys.2012.00260">0.5% to 1%</a> of muscle mass every year after age 50.</p>
<figure class="align-center ">
<img alt="Fruits and vegetables containing vitamin C." src="https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/355326/original/file-20200828-23-17lk1jc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fruits and vegetables, such as strawberries, citrus fruits, and broccoli, are all good sources of vitamin C.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fresh-fruits-vegetables-containing-vitamin-c-731190562">ratmaner/ Shutterstock</a></span>
</figcaption>
</figure>
<p>A similar picture was seen for both under- and over-65s, indicating vitamin C is likely to be important in both middle and older age. The findings were also supported by the fact that those with sufficient levels of blood vitamin C had greater muscle mass than those in the insufficient category.</p>
<p>This study complements the findings from <a href="https://doi.org/10.1007/s00223-019-00641-x">our previous work</a> in young and older women. There we found that women who ate more vitamin C not only had more muscle mass but also had much better leg function, meaning they were stronger. Our new findings in older age groups and men add more certainty that vitamin C is important for maintaining muscle as we age in both young and older people. </p>
<p>Data shows that <a href="https://www.gov.uk/government/collections/national-diet-and-nutrition-survey">more than 80%</a> of over-75s in the UK don’t eat enough fruits and vegetables daily. Our study also found nearly 60% of men and 50% of women who participated were eating insufficient vitamin C, according to recommendations. The shortfall in intakes of fruit and vegetables could therefore have implications for muscle health at a population level. </p>
<p>Our new findings build on the concept that optimal nutrition may help reduce the decline in muscle. This provides further emphasis and encouragement for people of all ages to follow the healthy eating guidelines and eat a wide variety of vegetables and fruits each day, not only for general health but to protect their muscles.</p>
<p>As vitamin C is readily available in vegetables and fruits, eating more should be relatively straightforward and have benefits for skeletal muscle health in people of all ages. But where improving diet is not possible, supplements may provide a suitable alternative.</p><img src="https://counter.theconversation.com/content/145125/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The vitamin could also protect against sarcopenia, which affects more than 50 million people globally.Ailsa Welch, Professor of Nutritional Epidemiology, University of East AngliaRichard PG Hayhoe, Senior Research Associate in Public Health Nutrition, University of East AngliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1443162020-08-24T13:55:09Z2020-08-24T13:55:09ZReverse dieting: slowly increasing calories won’t prevent weight regain – but may have other benefits<figure><img src="https://images.theconversation.com/files/354379/original/file-20200824-18-9k33xn.jpg?ixlib=rb-1.1.0&rect=50%2C0%2C5645%2C3523&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Proponents of the diet claim slowly increasing calorie intake can boost your metabolism.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/eating-leisure-concept-group-people-having-795968329">Syda Productions/ Shutterstock</a></span></figcaption></figure><p>While there are many debates about which type of <a href="https://theconversation.com/low-carb-paleo-or-fasting-which-diet-is-best-89685">diet is best</a> for weight loss and health, it’s often not the weight loss which is the biggest challenge, but rather avoiding weight regain afterwards. This can lead to cycles of dieting and weight gain, or “yo-yo” dieting, which can cause people to have a <a href="https://europepmc.org/article/med/8581076">less healthy relationship</a> with food, <a href="https://www.sciencedirect.com/science/article/pii/S0091743517304966?casa_token=sF9VkYaOJE4AAAAA:ON01qcM7asAWqSo_UDHPjrZdgjlCwGMNspU6_nyb-3HwS3rxWjDa2k-0HN8ng7bzVxWuekUsyEE">worse mental health</a> and a <a href="https://www.sciencedirect.com/science/article/pii/S0261561411001105?casa_token=s3I0JUq90tsAAAAA:MUQTVVkStUL7VezwwmiiejJHMcasyvQzwrTF82U8w-SH5U6jym-o4dXXQjMJngLuNHnW70Ubts0">higher body weight</a>. </p>
<p>But recently, “reverse dieting” has gained popularity online as a post-diet eating plan that claims it can help you avoid weight regain by eating more. In simple terms, it’s a controlled and gradual way of increasing from a low calorie weight-loss eating plan back to your more “normal” pre-diet way of eating. </p>
<p>The idea with reverse dieting is that gradually increasing calorie intake following a deficit will allow your body and your metabolism to “adjust” so that you can avoid weight regain while eating more. However, there is currently no scientific evidence showing that reverse dieting works as advocates claim.</p>
<h2>Metabolic rate</h2>
<p>Reverse dieting is based around the theory that our body has baseline “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039924/">set points</a>” for metabolism and calorie intake hardwired into our biology, and if we go above these points we gain weight. The idea is that reverse dieting can shift these “set points” upwards if a person slowly increases the amount of calories eaten as food. This would theoretically “boost” their metabolism, allowing them to consume more food and calories without gaining weight. </p>
<p>However, the idea that as humans we have a “set point”, which we can manipulate with dietary changes, is not supported <a href="https://www.sciencedirect.com/science/article/abs/pii/S001650851730152X">by research</a>. The main reason for this is because a <a href="https://www.sciencedirect.com/science/article/abs/pii/S001650851730152X">number of factors</a> influence our weight and metabolism, including how it changes. Among them are how we’re brought up, what food we have access to, what type of exercise we do, and our genetics. </p>
<p>But the most important influence over how our body uses calories – and therefore our weight – is our resting (or basal) metabolic rate. This is the amount of calories our body needs in order to keep itself alive. This accounts for about 60%-70% of the calories we use daily. </p>
<p>Our basal metabolic rate is mostly determined by our age, weight, sex and muscle mass – your diet has little effect on it. Eating at or below your basal metabolic rate will result in weight loss, and eating above it will result in weight gain. Our basal metabolic rate also increases as we <a href="https://pubmed.ncbi.nlm.nih.gov/16277825/">gain weight</a> or <a href="https://www.jci.org/articles/view/114857">muscle mass</a>, and decreases as we lose weight or muscle mass (the evidence shows that the <a href="https://www.jci.org/articles/view/114857">more muscle</a> your body has, the more calories it needs to function). </p>
<figure class="align-center ">
<img alt="Two men lifting barbell with weights." src="https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/354381/original/file-20200824-20-xnj7y9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Greater muscle mass increases your basal metabolic rate.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-multiracial-sports-people-working-out-700042639">Dean Drobot/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Exercise also increases how many calories we use, but usually <a href="https://bjsm.bmj.com/content/49/15/967">not enough</a> to massively affect our weight. And though a high protein diet can <a href="https://www.nature.com/articles/0800810">alter metabolic rate</a> somewhat, our body weight and <a href="https://pubmed.ncbi.nlm.nih.gov/22935042/">muscle mass</a> have the greatest effect on it. </p>
<p>So reverse dieting only appears to work by controlling calorie intake. There’s currently <a href="https://academic.oup.com/ajcn/article/72/5/1088/4729774">no evidence</a> that you can alter your metabolism or metabolic rate by introducing more calories slowly and gradually. Put simply, if you eat more calories than your body requires, you will gain weight. What we do know is that <a href="http://nwcr.ws/Research/default.htm">certain habits</a>, like regularly eating breakfast and exercise, help people avoid weight regain after dieting. </p>
<h2>Food relationship</h2>
<p>While there’s currently little research investigating the effects of reverse dieting on metabolism, it could still help people in other ways. When some people are losing weight, they may feel in control of how they eat. But for some people, stopping their diet could lead to perceived loss of control. Reverse dieting might give some people the confidence to return to a more sustainable way of eating, or help them move out of a cycle of restrictive dieting.</p>
<p>Advocates of reverse dieting suggest it can also help manage problems of appetite and cravings. This is because additional foods can be added in as the amount of calories and food eaten is increased. While <a href="https://bpsmedicine.biomedcentral.com/articles/10.1186/s13030-017-0099-3">fewer cravings</a> can help with weight maintenance, this evidence does not come from studies where foods were slowly reintroduced. </p>
<p>For some people, counting calories or restrictive dieting can tend to lead to an unhealthy relationship with their bodies and <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/eat.22877?casa_token=RDuLE9eJyzMAAAAA%3ACnUCBJAGxWkhW02FpaKGi5pI1S4-QhlAHyrYDnK4siAOsg_IcEjfwEnnm_bRgBOu66GAsH1I_xI2kaq6">the food</a> they eat. <a href="https://www.nationaleatingdisorders.org/learn/by-eating-disorder/other/orthorexia">Orthorexia nervosa</a> is becoming increasingly common, and is characterised by an obsession with eating healthy – which can lead to an unhealthy restriction of and relationship with foods. While wanting to eat a healthy diet can seem on the surface to be a good thing, when it becomes orthorexia and enjoyment of food is replaced by an anxiety of feeling the need to account for every calorie, this could lead to poor mental health.</p>
<p>Reverse dieting is one approach, but some would argue other methods, such as <a href="https://theconversation.com/intuitive-eating-a-diet-that-actually-makes-sense-112800">intuitive eating</a> – which emphasises listening to your body’s hunger cues and only eating when you’re hungry – might be psychologically healthier. Intuitive eating may help people both regain and trust their appetites, and stop the cycle of restriction and calorie counting.</p><img src="https://counter.theconversation.com/content/144316/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Duane Mellor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There’s currently little evidence that ‘reverse dieting’ works.Duane Mellor, Senior Teaching Fellow, Aston Medical School, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1062682019-09-25T12:49:38Z2019-09-25T12:49:38ZHow biscuits enriched with protein could keep the UK’s ageing population strong<figure><img src="https://images.theconversation.com/files/245529/original/file-20181114-194513-526fk1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Could biscuits be the answer when it comes to helping old people retain their strength?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/712555009?size=huge_jpg&src=lb-59856941&sort=newestFirst&offset=3">Shutterstock</a></span></figcaption></figure><p>The world’s ageing populations are increasing every year. In 2016, <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/articles/overviewoftheukpopulation/july2017">18%</a> of the UK’s population was aged 65 years or older – by 2046, this group will account for nearly a quarter of the people living in the British Isles. </p>
<p>Add to this the fact that normal ageing is associated with a gradual decline in muscle mass, known as <a href="https://www.iofbonehealth.org/what-sarcopenia">sarcopenia</a> which can impair muscle function and strength, it is crucial, now and in the future, to prolong people’s health span and their ability to be active and live independently. For that we need to understand the role of dietary intake of protein to promote healthy and active ageing.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S1876382018306309?via%3Dihub">New evidence</a> suggests that current dietary recommendations for protein intake may be insufficient to achieve this goal and that individuals might benefit by increasing their intake and frequency of consumption of high-quality protein.</p>
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<p>From the third decade of life we begin to lose muscle mass and, scarily, losses of between <a href="https://www.mdpi.com/2072-6643/10/3/360">30 to 50%</a> have been reported between the ages of 40 and 80. Loss of muscle function and strength reduces the ability to perform everyday tasks and also increases the risk of falling.</p>
<p>So what can we do about it? Current UK dietary recommendations for protein intake in adults is set at 0.75g/kg of body weight per day regardless of age. But international recommendations specifically for older people vary between 1.2 and 1.5g/kg/day – although these do not take account for physical activity level. From mid-life onwards, adults may <a href="https://www.sciencedirect.com/science/article/pii/S1876382018306309?via%3Dihub">benefit from a greater intake of protein</a> to slow the ageing of muscles. Looking at the current UK intake of protein, there seem to be key areas for improvement:</p>
<p><strong>1. Protein amount:</strong> The amount of protein intake tends to decline with age, partially due to what is called <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/jcsm.12192">anorexia of ageing</a>, which happens when older people don’t eat regularly enough. The latest <a href="https://www.gov.uk/government/collections/national-diet-and-nutrition-survey">National Diet and Nutrition Survey</a> (NDNS) <a href="https://www.gov.uk/government/statistics/ndns-results-from-years-7-and-8-combined">data</a> indicates that one in three of over-40s do not meet the lower UK target of protein intake, and more than 80% fail to meet the international recommendations for healthy ageing.</p>
<p><strong>2. Distribution of protein intake:</strong> Consumption of two to three meals or snacks each containing <a href="https://www.sciencedirect.com/science/article/pii/S1876382018306309?via%3Dihub">25 to 30g protein</a> throughout the day is required for muscles to function at their best. However, estimates of protein intake in adults in mid-life indicate protein-rich meals tend to be eaten towards the <a href="https://www.nature.com/articles/ejcn2011210">end of the day</a>, at lunch or dinnertime.</p>
<p><strong>3. Type of protein:</strong> In the UK the main source of protein in the diet is from animal sources such as meat, dairy and fish. Increasing intake of <a href="https://www.bbc.co.uk/news/science-environment-45814659">plant-based proteins</a> such as pulses, cereal products and nuts might be a more sustainable dietary pattern. </p>
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<h2>Taking the biscuit</h2>
<p>Our <a href="https://www.mdpi.com/2072-6643/10/3/360">research</a> is part of the <a href="https://research.ncl.ac.uk/proteinforlife/">Protein For Life</a> project, a recent partnership between academia and industry which aims to address the issue of declining muscle function due to malnutrition.</p>
<p>As part of this project, higher-protein biscuits were formulated containing different amounts of protein – either 12% or 20% of total energy coming from protein. To put this in perspective, a typical digestive biscuit has around 6% of total energy coming from protein. Products were also enriched with different sources of protein: animal protein (whey powder) or plant protein (peanut butter, soya and wheat crispies). Higher-protein biscuits offer a handy on-the-go snack which can top up protein anywhere, at any time, and help spread intake throughout the day.</p>
<p>According to <a href="https://www.food.gov.uk/business-guidance/packaging-and-labelling#the-legislation">current legislation</a> for front-of-pack labelling, these products could also be labelled as a “source of protein” or “high in protein” for the 12% and 20% protein biscuits respectively, alerting consumers to their “protein power”.</p>
<p>A group of older adults (40 and upwards) took part in a blind test to find out which biscuit (and therefore level of protein enrichment) was preferred, and whether they tasted good. Biscuit tasting at the trial site in Aberdeen (one of four across the UK) revealed that the source-of-protein biscuits (12%) were favoured over the high-protein biscuits (20%). This suggests that consumers might favour a more subtle approach to reformulating much-loved products with extra protein.</p>
<p>Although members of the test group were divided over the type of protein used, more indicated that they generally prefer plant over animal sources of protein. This potentially identifies a niche for food products enriched with plant proteins specifically, which would help to reduce the environmental impact of the protein-enriched biscuit. From our research into the use of plant proteins to support healthy ageing, we have created a <a href="https://admin.ktn-uk.co.uk/app/uploads/2019/04/KTN-Protein4Life-Booklet-Digital.pdf">framework for action</a> that explains clearly the issues facing the elderly – and what can be done by the government, the food industry and consumers themselves. </p>
<p>Our study raises important points about how the foods we eat affect our long-term health and our environment. Enriching biscuits with protein is a simple and easy way to ensure older people keep their protein levels at a constant level. It could help contribute to prolonged health and independence, and crucially, mean a better quality of life in old age.</p><img src="https://counter.theconversation.com/content/106268/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alex Johnstone receives funding from the Medical Research Council, The University of Aberdeen, The Scottish Government, Biological Sciences Research Council, Economic and Social Research Council, Engineering and Physical Sciences Research Council, National Health Service Endowments award, Tennovus Charity, Chief Scientist Office and European Community.</span></em></p><p class="fine-print"><em><span>Madeleine Myers does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Delivering the extra protein older people need via biscuits could be a simple and effective way to help guard against muscle loss in ageing.Alex Johnstone, Personal Chair in Nutrition, The Rowett Institute, University of AberdeenMadeleine Myers, Research Assistant, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1102352019-01-25T12:14:02Z2019-01-25T12:14:02ZGym break won’t mean you ‘lose it’ when it comes to muscles<figure><img src="https://images.theconversation.com/files/254744/original/file-20190121-100267-su9i1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/754741705?src=QSr6ImydM75vbur3IgZz3g-1-0&size=medium_jpg">Roman Samborskyi/Shutterstock</a></span></figcaption></figure><p>Our muscles grow as a result of regular exercise and can waste away when not frequently or strenuously used, leading to the popular maxim: “Use it or lose it.” But a <a href="https://www.frontiersin.org/articles/10.3389/fphys.2018.01887/abstract">new review</a> of what we know about muscles during periods of regular exercise or disuse casts doubt over long-held beliefs about how our muscles grow and adapt.</p>
<p>Skeletal muscle cells (fibres) are the largest cells in the human body and contain thousands of individual nuclei to support their large volume. These nuclei are the control centres of each cell and, as well as housing DNA, coordinate a range of cell activities, including their growth.</p>
<p>Historically, scientists thought that each nucleus regulates a limited cell volume and that the ratio between the nucleus and cell volume was constant, termed a “nuclear domain”. In skeletal muscle, this means that during periods of growth, such as regular weight training, nuclei must be added to the fibre from the stem cell pool located outside the fibre. </p>
<p>In general, this concept appears to hold true. <a href="https://www.physiology.org/doi/full/10.1152/japplphysiol.01215.2007">For example</a>, people who experience the greatest muscle growth after weight training also have the biggest increase in the number of nuclei in their fibres. This increased nuclear content allows muscle fibres to continue to function and grow optimally.</p>
<h2>Muscle memory</h2>
<p>If you spend long enough hanging around gyms, you will no doubt hear anecdotes about someone who has recently started lifting weights again after a few years away and is packing on muscle much faster than the other new gym goers. These tales from the locker room are in fact supported by <a href="https://www.ncbi.nlm.nih.gov/pubmed/1827108">scientific evidence</a> and recent research suggests that retention of nuclei within muscle fibres may provide the reason why.</p>
<p>According to the nuclear domain theory, nuclei are lost when muscle size decreases, such as during long periods of inactivity, in order to maintain a constant ratio between the nuclear number and cell volume. Over the past decade, though, a series of experiments have found that nuclei are retained when muscle size decreases. These experiments (including this one in <a href="https://www.ncbi.nlm.nih.gov/pubmed/18317591">mice</a>) have shown that when muscles are immobilised or the nerve supply is blocked, the muscle fibres shrink, but no loss of nuclei occurs.</p>
<p>More recently, <a href="https://www.ncbi.nlm.nih.gov/pubmed/30099751">research</a> in rats found that nuclei gained by muscle after training were maintained during long periods of not training. These nuclei then helped the muscle to regrow more effectively when training was resumed. It seems that muscle has a “memory” that helps explain why people who get back into the gym after some time away from training find it easier to gain muscle compared with newbies. </p>
<p>Although the saying “use it or lose it” is true for muscle size, per se, “use it or lose it until you use it again” is a more accurate – if less catchy – way to put it. </p>
<h2>Implications for doping in sport</h2>
<p>The World Anti-Doping Association bans steroid use because they cause large increases in muscle size which in some sports may be advantageous. Steroids or their byproducts can be detected in urine and blood samples for a short period of time, but the benefits of steroid use on muscle growth may last long after traces in urine and blood have vanished.</p>
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<img alt="" src="https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=392&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=392&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=392&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255357/original/file-20190124-135160-qspsfk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=492&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Doping cheats may never be caught.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/622092452?src=N1vjypjZZmAeI-vOVgQu9A-1-7&size=medium_jpg">279photo Studio/Shutterstock</a></span>
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<p>We now know from <a href="https://www.ncbi.nlm.nih.gov/pubmed/24167222">studies in mice</a> that when muscles grow in response to steroid use, they also gain nuclei, which are retained when muscles have returned to their normal size after steroid withdrawal (muscle memory). When the muscles of these mice are then loaded to mimic weight training, the extra nuclei help muscles grow faster and much bigger than muscles in normal mice. This means that athletes can benefit from using steroids to grow their muscles without the fear of detection, and might do so already.</p>
<p>On the plus side, these recent findings on the biology of muscle adaptation and memory could provide insights on how to combat muscle wasting associated with ageing, disease and prolonged hospitalisation.</p><img src="https://counter.theconversation.com/content/110235/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Neil Martin currently holds funding from the Rank Prize Funds. </span></em></p>And why doping cheats may never be caught.Neil Martin, Lecturer in Cellular & Molecular Biology, Loughborough UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/830932017-11-08T03:21:36Z2017-11-08T03:21:36ZHealth Check: which sports supplements actually work?<figure><img src="https://images.theconversation.com/files/192571/original/file-20171031-18693-1w66512.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">With so many products on the market, it's hard to know which supplements are scientifically proven to work.</span> <span class="attribution"><a class="source" href="https://c1.staticflickr.com/6/5296/5463228242_231f5264c7_b.jpg">David van der Mark/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Whether your goal is to increase strength, decrease body fat or improve overall performance, adding supplements to your daily regimen can give you that extra edge. But with thousands of products on the market, choosing the ones that are right for you can be overwhelming.</p>
<p>That said, here are some of the more popular supplements on the market today, separated into three categories:</p>
<ol>
<li>Green – their effectiveness is well supported by scientific evidence and they are considered safe to use</li>
<li>Yellow – there is somewhat inconclusive evidence for their effectiveness, but they are still considered safe</li>
<li>Red – there is minimal research to support the claims of effectiveness, but ingredients are generally well tolerated unless taken in too-large doses.</li>
</ol>
<h2>Green</h2>
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<a href="https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192587/original/file-20171031-18735-18ia0ng.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">These supplements are well supported by evidence and safe to use.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
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<img alt="" src="https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=784&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=784&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=784&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=985&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=985&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192574/original/file-20171031-18704-fz21ex.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=985&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Creatine is a natural substance our body uses to produce energy.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/blonyx/24746368121">Blonyx/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p><strong>Creatine monohydrate</strong> has been around for decades as a supplement, and there are literally hundreds of published studies supporting its <a href="https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0173-z">benefits and safety</a>. Creatine is a natural substance our body uses to produce energy. The body turns creatine into phosphocreatine, which is stored in the muscles. </p>
<p>Creatine supplementation works by increasing its availability in the muscle. This helps to maintain energy during high-intensity exercise such as lifting weights, circuit workouts and interval runs. Increasing the availability of phosphocreatine may also help speed up recovery between sets.</p>
<p>Long-term creatine supplementation appears to enhance the quality of resistance training, generally leading to <a href="https://www.ncbi.nlm.nih.gov/pubmed/12701815">5-15% greater gains</a> in strength and performance.</p>
<p>Creatine can also be beneficial for endurance athletes. US research found when athletes took creatine five days before a typical <a href="https://en.wikipedia.org/wiki/Carbohydrate_loading">carb-loading protocol</a> (a strategy for maximising energy storage), glycogen levels in their bodies <a href="https://www.ncbi.nlm.nih.gov/pubmed/11445755">increased by 53%</a>. Glycogen is essential for long-term energy storage in the muscles. </p>
<p>Because of the strong relationship between high glycogen stores and performance during prolonged exercise, creatine could be quite beneficial in endurance activities.</p>
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<a href="https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1104&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1104&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1104&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1387&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1387&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192591/original/file-20171031-18725-1gn7gc7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1387&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fast-digesting proteins, like whey, are optimal after a workout.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/fdaphotos/20153946616">The US Food and Drug Administration/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p><strong>Whey protein</strong> is a fast-digesting protein, and can help improve your muscles’ ability to recover and adapt after strenuous exercise. </p>
<p>Proteins are made up of amino acids and are responsible for many different functions in the body, as well as being an important source of energy. A review in the <a href="http://ajcn.nutrition.org/content/96/6/1454">American Journal of Clinical Nutrition</a> showed that supplementing with protein during resistance training can lead to significantly greater increases in muscle mass and strength when compared to resistance training without a dietary protein.</p>
<p>You can certainly meet your daily protein needs through wholefoods alone, but nothing beats the convenience of a ready-to-drink protein source, like whey protein powder, to jump-start the process of muscle building and repair.</p>
<p>In fact, consumption of whey protein has been found to stimulate muscle protein synthesis to a greater degree than other proteins like <a href="http://acaiwhey.com.br/site/artigos/5.pdf">casein</a> and <a href="http://www.tandfonline.com/doi/full/10.1080/07315724.2013.793580">soy</a>.</p>
<h2>Yellow</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192593/original/file-20171031-18725-3io8ih.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There is inconclusive evidence for the effectiveness of these supplements, but they are considered safe to use.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192594/original/file-20171031-18689-zyd68b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There are claims BCAAs can improve muscle mass and help reduce fatigue.</span>
<span class="attribution"><a class="source" href="https://c1.staticflickr.com/1/717/22353684370_845ae68730.jpg">Superfit asia/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p><strong>BCAAs</strong> are branched-chain amino acids, which include the amino acids leucine, isoleucine and valine. These are among the nine essential amino acids (the building blocks of proteins) not made naturally in the body. Instead, these need to be supplied through the diet. </p>
<p>They’ve become quite popular over recent years due to claims they can <a href="https://www.bodybuilding.com/fun/bcaas-the-many-benefits-of-amino-acids.html">increase muscle protein synthesis</a> and suppress protein breakdown. It has also been suggested they can help reduce fatigue during prolonged exercise by reducing the amount of serotonin produced in the brain.</p>
<p>Despite limited research showing that acute supplementation with BCAAs may <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461297/">improve protein synthesis</a> after a bout of resistance training, there isn’t a whole lot of evidence that this actually leads to <a href="https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0184-9">greater muscle mass</a> in the long run. They have, however, been shown to reduce delayed onset of <a href="https://www.ncbi.nlm.nih.gov/pubmed/20087302">muscle soreness</a> following intense exercise.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=802&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=802&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=802&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1008&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1008&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192603/original/file-20171031-18738-6ek3qp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1008&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fish oil can help muscle recovery after exercise.</span>
<span class="attribution"><a class="source" href="http://www.elitevitaminzone.com.au/buy/triple-strength-fish-oil-by-carusos-150-caps/TRIP150?gclid=EAIaIQobChMIpZWry6Ka1wIVlAgqCh1RsgqyEAYYByABEgJkN_D_BwE">Screen shot</a></span>
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</figure>
<p><strong>Fish oils</strong> are an excellent source of omega-3 fatty acids, key players in the muscle recovery process. Intense resistance training can cause microscopic tears in your muscle fibres, leading to muscle damage and inflammation. While some inflammation is desirable, too much can delay recovery.</p>
<p>Research suggests omega-3 fatty acids may help reduce <a href="https://www.ncbi.nlm.nih.gov/pubmed/19451765">muscle soreness</a> after exercise and speed up the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3737804/">recovery process</a>, getting you ready for your next session with the weights.</p>
<h2>Red</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192912/original/file-20171101-19876-60jegm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There is minimal research to support the effectiveness of these supplements.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1147&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1147&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1147&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192602/original/file-20171031-18711-ocsl81.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The majority of studies examining effects of testosterone boosters have produced underwhelming results.</span>
<span class="attribution"><a class="source" href="http://testosteroneboosteradvice.com/six-star-testosterone-booster/six-star-testosterone-booster-5/">Screen shot</a></span>
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</figure>
<p><strong>Testosterone boosters</strong> are a class of herbal supplements that claim to <a href="https://www.bodybuilding.com/fun/do-testosterone-boosters-really-work.html">naturally increase your testosterone levels</a>. By directly increasing testosterone, or by inhibiting hormones responsible for converting testosterone to oestrogen (the female hormone), these supplements are designed to help you build bigger, stronger muscles.</p>
<p>Some commonly used ingredients, like <a href="https://www.ncbi.nlm.nih.gov/pubmed/24074738">D-aspartic acid</a> (which increases natural testosterone production), <a href="https://jissn.biomedcentral.com/articles/10.1186/1550-2783-7-34">fenugreek</a> (which enhances creatine uptake) and <a href="https://www.asep.org/asep/asep/BrillaV2.PDF">ZMA</a> (a formula of zinc, magnesium and vitamin B6 used to help achieve a more restful sleep) have been shown to increase testosterone levels and lean body mass. But the <a href="http://digitalcommons.wku.edu/ijesab/vol2/iss1/13/">majority of studies</a> <a href="https://jissn.biomedcentral.com/articles/10.1186/1550-2783-1-2-12">examining the effects</a> of testosterone boosters have produced <a href="https://www.ncbi.nlm.nih.gov/pubmed/24074738">underwhelming results</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=926&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=926&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=926&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1163&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1163&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192604/original/file-20171031-18704-1wk9u5m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1163&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Glutamine is one of the most overhyped supplements on the market.</span>
<span class="attribution"><a class="source" href="http://www.gnc.com/l-glutamine/350319.html?cgid=l-glutamine">Screen shot</a></span>
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</figure>
<p><strong>Glutamine</strong> is one of the most overhyped supplements on the market. Claims it can boost <a href="https://www.ncbi.nlm.nih.gov/pubmed/9624643">your immune system</a> or <a href="https://www.ncbi.nlm.nih.gov/pubmed/9650740">reduce muscle soreness</a> are not well supported in the literature. Yet it’s still <a href="https://www.bodybuilding.com/fun/glutamine.htm">recommended to many</a>, especially those in the bodybuilding community. </p>
<p>Glutamine is the most abundant amino acid in your body. It’s critical for numerous processes, including transporting nitrogen in a non-toxic form from the muscle to the liver. But because your body can already make enough glutamine to support these processes, supplementation is not necessary and a waste of your money.</p>
<p>While the research on glutamine supplementation in healthy individuals is less than promising, it may be useful in certain scenarios, such as periods of <a href="https://www.ncbi.nlm.nih.gov/pubmed/12352035">critical illness</a>. For patients <a href="https://www.ncbi.nlm.nih.gov/pubmed/11533310">undergoing surgery</a>, or for those who have experienced <a href="https://www.ncbi.nlm.nih.gov/pubmed/14530749">extensive burn injuries</a>, glutamine supplementation has been shown to reduce infection rates and shorten hospital stay. </p>
<p>Glutamine and ingredients used in testosterone booster products are generally well tolerated when taken as intended or directed.</p>
<p>Remember, though, before you make any changes to your diet and supplement plan, or if you have any underlying health conditions, make sure to consult your physician.</p><img src="https://counter.theconversation.com/content/83093/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Krissy Kendall does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Here are some of the more popular sports supplements on the market today, separated into categories based on how effective and safe research shows they are.Krissy Kendall, Lecturer of Exercise and Sports Science, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/747592017-04-04T19:23:11Z2017-04-04T19:23:11ZWhole body vibration: a genuine therapy or just another ‘weight loss’ fad?<figure><img src="https://images.theconversation.com/files/162619/original/image-20170327-3273-bor3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Is whole body vibration just another fitness fad?</span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p>Vibration machines have popped up in gyms alongside traditional equipment, and manufacturers claim ten minutes of vibration a day can be <a href="http://www.cardiotech.com.au/vibration-machines">equivalent to an hour</a> spent working out. Standing on a rapidly shaking platform will, according to claims, improve muscle tone and circulation, and accelerate weight loss.</p>
<p>It’s an appealing prospect: passively standing on a platform and doing, well nothing, while your body seemingly tones and loses weight on its own. But is there evidence these vibration machines actually work as they say they do?</p>
<h2>How does it work?</h2>
<p>Whole body vibration therapy was initially developed for athletes to improve the effectiveness of their training. Vibration platforms would be included in some regular conditioning and gym exercises such as squats, press-ups and step-ups. </p>
<p>The therapy is undertaken by standing, sitting, lying or doing exercises on specifically designed equipment that oscillates, generally in a horizontal plane, at relatively high frequencies. </p>
<p>The theory is that the vibration signals are transferred into body tissues, tendons and muscles, which increases <a href="https://www.ncbi.nlm.nih.gov/pubmed/12562163">muscle contractions</a> and ultimately improves muscle strength, co-ordination and balance. In the long term, such contractions would increase muscle mass and energy expenditure, leading to <a href="https://www.ncbi.nlm.nih.gov/pubmed/3522140">better control of blood sugar</a> levels. </p>
<p>Current theory also suggests bone cells are sensitive to this vibration and respond by increasing bone density. This has a further impact on <a href="https://www.ncbi.nlm.nih.gov/pubmed/20734028">better sugar control</a>. </p>
<p>But these are still theories. The overall effects of whole body vibration therapy remain elusive, as scientific studies vary largely in the vibration parameters used.</p>
<p>A <a href="https://academic.oup.com/endo/article-abstract/doi/10.1210/en.2016-1250/3070534/Whole-body-vibration-mimics-the-metabolic-effects?redirectedFrom=fulltext">recent study</a> comparing whole body vibration with exercise in male mice specifically bred to be become obese and diabetic showed whole body vibration was equivalent to exercise for improving muscle quality, control of blood sugar and improving bone health. </p>
<p>It was also equivalent in reducing fat tissue – especially in the abdomen, which is known as “bad” fat. But caution should be exercised when applying findings from this or any other animal study directly to humans.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/163791/original/image-20170404-5700-9z1qb1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Recent research found whole body vibration therapy has weight-loss benefits for mice.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Can it enhance weight loss?</h2>
<p>There are a number of significant differences between humans and mice. These include size and gait (two legs compared to four). The vibration protocol for rodents would also have likely been more extreme compared to what humans could safely tolerate. </p>
<p>A review of trials for whole body vibration therapy in humans showed the outcomes were <a href="https://www.ncbi.nlm.nih.gov/labs/articles/24160189/">far less convincing</a>. Whole body vibration therapy alone (without exercise) – usually three times per week, ten to 60 minutes per day over periods of six to 52 weeks – does not support meaningful weight loss (considered to be more than 5% body weight). </p>
<p>While small individual studies report weight loss, their methodologies often combine diets or other exercises. Such benefits are <a href="https://www.karger.com/Article/Abstract/301785">rarely seen</a> with whole body vibration therapy alone. </p>
<p>However, isolated whole body vibration therapy in similar time doses (30 to 60 minutes) does promote physical conditioning, muscle strength, bone health and functional capacity to a similar extent as the currently recommended 30 to 60 minutes of light to moderate exercise per day. </p>
<h2>Other health benefits</h2>
<p>Whole body vibration therapy has now been tested as a potential stand-alone therapy in a number of patient groups where their mobility, capacity or desire to undertake exercise is limited but it is a recommended therapy. </p>
<p>These groups include those who have suffered <a href="https://www.ncbi.nlm.nih.gov/pubmed/25311142">cerebrovascular events</a> like a stroke; those with <a href="https://www.ncbi.nlm.nih.gov/pubmed/25827655">osteoarthritis</a> where mobility is limited; those with <a href="https://www.ncbi.nlm.nih.gov/pubmed/26038611">chronic obstructive pulmonary diseases</a> who find exercising difficult as they struggle to breathe; and those with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5080200/">type 2 diabetes</a> and <a href="http://josr-online.biomedcentral.com/articles/10.1186/s13018-016-0357-2">post-menopausal women</a> who may have limited motivation to undertake exercise. </p>
<p>The studies found benefits of whole body vibration therapy in these groups. But it was limited to improved bone health and capacity to walk or transitioning from a seated to standing position. These outcomes ultimately reduce risk of falls and fractures, and increase capacity to undertake activities of daily living.</p>
<p>So this means body vibration may have a role in preventing weight gain and improving functional capacity and bone health in groups of people where normal exercise or physical activities are significantly impaired. More rigorous research is still needed. </p>
<p>Overall, if you’re physically able, you’ll have far more benefits taking a 30-minute walk with friends, or engaging in 30 minutes of outdoor activities in the backyard or park with your family, rather than standing in one place being vibrated for 30 to 60 minutes.</p><img src="https://counter.theconversation.com/content/74759/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nigel Stepto is affiliated with the Australian Institute for Musculoskeletal Science (AIMSS), The Institute of Sport Exercise and Active Living and Monash Centre for Health Research and Implementation. He is also full member of Exercise and Sport Science of Australia (ESSA) and an ESSA accredited Exercise physiologist, which includes roles on their national research committee. </span></em></p>Whole body vibration therapy is undertaken by standing, sitting, lying or doing exercises on specifically designed equipment that oscillates at relatively high frequencies.Nigel Stepto, Associate Professor in Exercise Physiology and Research Associate of Institute of Sport Exercise and Active Living (ISEAL), Victoria UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/646042016-09-02T05:41:29Z2016-09-02T05:41:29ZCreatine: what is it and should we supplement our diets with it?<figure><img src="https://images.theconversation.com/files/136041/original/image-20160831-791-2o7nuc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Body builders take creatine supplements to build big muscles – but what is it, is it good for you, and does it have other uses?</span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>Named after the Greek word <em>kreas</em>, meaning flesh, creatine is an amino acid derivative found in all cells in the body, but is stored primarily in muscle. It <a href="http://www.ncbi.nlm.nih.gov/pubmed/9746337">plays an important role</a> in tissues where <a href="http://www.ncbi.nlm.nih.gov/pubmed/21448658">energy levels quickly rise and fall</a>, such as muscle.</p>
<p>Creatine acts as a short sharp burst of recharge for our cells. Creatine also moves energy around the cell, from where it is generated to where it is needed.</p>
<p>As the name suggests, creatine is naturally found in flesh and is acquired through a diet rich in fish, meat and other animal products such as dairy. As creatine is important for all cells to function, our body also makes its own.</p>
<p>A diet containing animal products can account for 50% of daily creatine requirements, with the other 50% <a href="http://www.ncbi.nlm.nih.gov/pubmed/11595668">being made by the body</a>.</p>
<p>Those on an animal-free diet will naturally have a higher burden placed on the body to meet its entire creatine requirement. However, under normal circumstances, a healthy person can maintain adequate creatine levels even if they choose to follow a vegetarian or vegan diet.</p>
<h2>Why do people take creatine supplements?</h2>
<p>Natural and supplemental creatine have the same effect in the body – the concentration of creatine in a supplement is just much higher. This is why athletes often use creatine supplements to help them train and increase muscle performance. </p>
<p>The standard dosing regime for an athlete is an initial dose of 0.3g for each kilogram of body weight per day (so if you’re 60kg you would take 60 x 0.3 = 18g of creatine every day) for a week. Then an ongoing dose would be 0.075g per kg per day (or 4.5g per day for the same 60kg person). When your body reaches the threshold of creatine it can absorb, the excess will come out in urine.</p>
<p>Creatine is also important for brain function, as your brain uses a lot of energy. Some choose to take creatine to help boost <a href="http://www.ncbi.nlm.nih.gov/pubmed/21324203">alertness</a>, and <a href="http://www.ncbi.nlm.nih.gov/pubmed/19253023">numerous studies</a> are underway to assess whether creatine supplements might be useful for <a href="http://www.ncbi.nlm.nih.gov/pubmed/22465051">neurodegenerative diseases</a> such as Parkinson’s and mild depression.</p>
<p>There isn’t enough information about the use of creatine supplementation in children, adolescents and pregnant women, so current guidelines recommend that they don’t take it. Those with pre-existing kidney conditions should also seek professional advice before taking supplements including creatine.</p>
<p>While the supplements are safe for the general public, there is no need to supplement a normal balanced diet with creatine products.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/136042/original/image-20160831-830-142nkm2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gym-goers often use creatine, protein and other supplements to maximise their workouts – some with evidence and some without.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/johnjeddore/3446535934/in/photolist-6fyp4m-pWzEoQ-bSQLWx-o8A6B3-nX8sNZ-dBYdj5-DoU3QY-pt7LCS-xP1og6-DGKB6k-xmDvEZ-Bd61z7-nsmQ8v-ph2qVy-xmxaw3-AhqwsR-tkAb8P-AhhT35-AAkGD8-g6zJ6v-nj4KVx-qNiuRk-CTBVRB-AhhT23-v9MDaz-ACDY5c-BejD6p-Ahqwpp-w6DT9p-nG7h8W-w6DTaX-CTER94-DECWhd-DR4kcX-DR1Fnx-e3KR2e-CTv7jf-DR1FyK-DhwrZH-wjqjQx-u21wGr-xgRhaR-vPauRV-wjqjPF-vGjg4v-xghJbt-xdYbum-C2ZAyA-v9MCtp-uUbBkU">John Jeddore/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Therapeutic uses of creatine</h2>
<p>Dietary creatine supplements <a href="http://www.ncbi.nlm.nih.gov/pubmed/9845353">have been trialled</a> as a treatment for a range of conditions where muscle fibres break down. A successful application of creatine in this area is the <a href="http://www.ncbi.nlm.nih.gov/pubmed/16536185">treatment of Duchenne Muscular Dystrophy</a>. </p>
<p>While still in the trial phase, long-term creatine supplementation (over four months) <a href="http://www.ncbi.nlm.nih.gov/pubmed/15159476">appears to improve muscle strength</a> and mass without adverse side-effects.</p>
<p>Creatine is also considered as an additional therapy to help ease the progression of neurodegenerative diseases such as <a href="http://www.ncbi.nlm.nih.gov/pubmed/17030762">Parkinson’s</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/15672208">Huntington’s disease</a>. Although <a href="http://www.ncbi.nlm.nih.gov/pubmed/26748651">the results of these studies</a> have been relatively unconvincing.</p>
<p>And while it is marketed as a supplement for the young and buff, creatine is <a href="http://www.ncbi.nlm.nih.gov/pubmed/17943308">also being trialled</a> to help the elderly maintain their muscle and bone mass to help reduce the burden of falls.</p>
<p>A link between creatine and fetal growth was <a href="http://rspb.royalsocietypublishing.org/content/86/585/88">established back in 1913</a>. During pregnancy, the rapidly increasing nutrient demands of the growing baby pose a considerable energy challenge for the mother. </p>
<p>Our <a href="http://www.ncbi.nlm.nih.gov/pubmed/25885219">recent</a> studies show creatine synthesis, excretion, transport and storage are all changed by pregnancy. In a <a href="http://www.ncbi.nlm.nih.gov/pubmed/27550725">study</a> of 270 women, our team found that pregnant woman who had less creatine in their urine gave birth to significantly smaller babies.</p>
<p>These results raise the possibility that improvements in maternal diet, ensuring inclusion of foods containing creatine (meat and fish), could protect a baby from poor growth.</p>
<p>The next step is to study maternal diet and maternal creatine concentrations throughout pregnancy. The findings may inform development of new dietary guidelines, including a minimum recommended creatine intake during pregnancy.</p>
<h2>Is creatine harmful?</h2>
<p>At times, creatine is confused with its breakdown product creatinine. The body maintains a tight ratio of creatine to creatinine, so the more creatine in your system the more likely you are to excrete <a href="http://www.sgsm.ch/fileadmin/user_upload/Zeitschrift/48-2000-3/5-2000-3_Schedel.pdf">excess creatinine in your urine</a>.</p>
<p>Increased creatinine in the urine is commonly taken as a sign that our kidneys aren’t properly filtering blood. This had led to published <a href="http://www.ncbi.nlm.nih.gov/pubmed/9643752">case studies</a> that link creatine use to kidney dysfunction. </p>
<p>While <a href="http://www.ncbi.nlm.nih.gov/pubmed/17046619">case studies have been published</a> that point to potential harms or side effects, <a href="http://www.ncbi.nlm.nih.gov/pubmed/20060630">scientific studies</a> testing these cases have concluded that creatine is safe.</p>
<p>In some cases creatine causes water retention. This could mean it has the potential to alter kidney function, but <a href="http://www.ncbi.nlm.nih.gov/pubmed/22101980">most studies have found this not to be the case</a>. <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC155510/">Some studies found</a> that the supplement caused weight gain, probably due to this increase in water.</p>
<p>The opinion of <a href="http://www.ncbi.nlm.nih.gov/pubmed/10731017">most experts</a> is that creatine does not <a href="http://www.telegraph.co.uk/sport/rugbyunion/international/newzealand/12177904/Jonah-Lomus-former-team-mate-believes-use-of-creatine-may-have-contributed-to-his-death.html">cause the type of nephrotic syndrome</a> (kidney disease) that sadly claimed the life of rugby star Jonah Lomu, as some thought.</p>
<h2>Should pregnant women take creatine supplements?</h2>
<p>The <a href="http://www.ncbi.nlm.nih.gov/pubmed/21448658">evidence to support the use</a> of creatine to enhance muscle performance is pretty clear. Throughout the <a href="http://www.ncbi.nlm.nih.gov/pubmed/19253023">countless studies</a> of creatine supplementation in the sports arena, and in clinical studies, creatine has a good safety record.</p>
<p>But there is no human safety data of creatine supplementation during pregnancy. While our work found mothers with higher levels of creatine in their urine are less likely to have a small baby, these data are based on women’s regular diets, without creatine supplementation. </p>
<p>So, at this time there is no evidence to suggest creatine supplements are necessary for pregnant women. Simply eating a balanced diet, containing meat and fish, will ensure women receive adequate creatine for themselves and their babies.</p>
<hr>
<p><em>Update: the article originally stated Jonah Lomu played rugby league.</em></p><img src="https://counter.theconversation.com/content/64604/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hayley Dickinson receives funding from National Health and Medical Research Council, Cerebral Palsy Alliance, Stillbirth Foundation and The Andrea Joy Logan Trust for Medical Research.</span></em></p><p class="fine-print"><em><span>Stacey Ellery does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Named after the Greek word “kreas” meaning flesh, creatine is an amino acid derivative found in all cells in the body, but is stored primarily in muscle.Hayley Dickinson, Research Group Head, Embryology and Placental Biology, Hudson InstituteStacey Ellery, Hudson InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/646422016-08-31T12:46:20Z2016-08-31T12:46:20ZGym workout advice: protein guidance looks wrong, our findings suggest<figure><img src="https://images.theconversation.com/files/135964/original/image-20160830-28213-1nhm6d8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-270908915/stock-photo-young-handsome-sporty-man-in-the-studio-with-a-bottle-in-his-hand.html?src=86G41jfvwFKagtXsMGaqXg-1-24">Lebedev Roman Olegovich</a></span></figcaption></figure><p>Visit a gym regularly and you’re bound to hear a conversation along the lines of: “I’ve just started my new whey protein shake. It says one scoop post-workout on the tub, but I take two just to make sure.” </p>
<p>Until now, sports nutritionists would have said you’re wasting your money. All the research has indicated that you need only one scoop (20g-25g) of high-quality protein <a href="http://ajcn.nutrition.org/content/99/1/86.long">whey</a> or <a href="http://ajcn.nutrition.org/content/89/1/161.long">egg white</a> to maximise the growth effects of a weight-training workout. Taking more has appeared to offer little if any additional benefit. This is why the dose recommended on the tub is usually one scoop per workout. </p>
<p>But recent work from our lab reveals otherwise. It raises the need for a major shift in sports nutrition recommendations. For many people, it looks like the gym logic may not be so far wrong after all. </p>
<p>The links between protein and resistance exercise are complicated. It is becoming clearer, though, that an amino acid found in higher levels in higher-quality proteins called leucine is <a href="http://onlinelibrary.wiley.com/doi/10.1111/1750-3841.12802/abstract;jsessionid=FAFBCEA89D92A3637F4B1F916D5D0947.f02t03">intricately linked</a> to muscle-building – <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447149/">or even</a> the key amino acid in the process. Whey’s superiority to soy as a muscle-building protein has been <a href="http://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-9-57">attributed to</a> its leucine content, for example.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=965&fit=crop&dpr=1 600w, https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=965&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=965&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1213&fit=crop&dpr=1 754w, https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1213&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/135967/original/image-20160830-28230-1onlh3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1213&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Whey to go.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-361876367/stock-photo-bodybuilder-holding-a-black-plastic-jar-with-whey-protein-isolated-on-white-background.html?src=ifZ8Rjtcp9Qyh-9PNYNd0g-1-91">Chetty Thomas</a></span>
</figcaption>
</figure>
<p>On the question of the right protein dose, we already knew that age is relevant. The findings to date have all related to young healthy adults. <a href="http://link.springer.com/article/10.1007/s40279-016-0504-2/fulltext.html">No such maximum</a> response to protein has been noted in older adults. Some research <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8755874&fileId=S0007114511007422">suggests</a> the optimal dose for older adults might be 40g or possibly even higher – double the amount needed by younger people, in other words. Certainly in the rested state we <a href="http://biomedgerontology.oxfordjournals.org/content/70/1/57.long">know that</a> older adults need at least double the protein dose that young adults need to maximise muscle-building from eating. </p>
<h2>One size fits all?</h2>
<p>We have been looking at two other factors whose effect on the optimal protein dose after a workout has never been clear: the amount of muscle the individual possesses and the amount of muscle being exercised. In other words, does a 90kg rugby player need the same dose of protein post-workout as a 60kg boxer? And will the rugby player need more protein if he works out his whole body as opposed to only his legs? </p>
<p>Believe it or not, these questions had never been empirically tested. The recommendations of protein post-workout come primarily <a href="http://ajcn.nutrition.org/content/99/1/86.long">from</a> two <a href="http://ajcn.nutrition.org/content/89/1/161.long">studies</a> of resistance-trained young men with similar body mass (80kg to 85kg) working out only part of the body (the legs). </p>
<p>In lieu of any research findings, recommending 20g-25g for all young healthy adults has been merely an <a href="http://www.gssiweb.org/Article/sse-107-protein-consumption-and-resistance-exercise-maximizing-anabolic-potential">attempt to</a> take account of possible variations from person to person – while not even acknowledging that many athletes perform whole body workouts in the real world. Quite rightly, this one size fits all approach has been <a href="http://www.muscleforlife.com/guide-to-post-workout-nutrition/">questioned</a> by many in the business. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/135972/original/image-20160830-28240-1lx3uso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Heave.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-197440790/stock-photo-fitness-woman-in-trainingstrong-abs-showing.html?src=q0SVsAmBpAMeVqXmzlrOAQ-1-32">beccarra</a></span>
</figcaption>
</figure>
<p>For <a href="http://physreports.physiology.org/content/4/15/e12893">our study</a>, we recruited two groups of male weightlifters, one with 65kg or less of muscle mass and one with 70kg or more. We assessed the muscle-building response after a whole body routine of weightlifting. </p>
<p>What we found goes against a commonly accepted paradigm in sports nutrition. We showed that 40g of protein consumed post-workout was more effective than 20g of protein at stimulating the muscle-growth response. </p>
<p>This had nothing to do with the size of our participants, which made no difference to their protein requirement. It appears that the amount of muscle you work in a single session is more important to the optimal dose of protein post-workout than the absolute amount of muscle you possess – though it is important to stress that we did not explicitly test this question. </p>
<p>Though our data will require further validation, the results suggest that the recommended protein intake will in future depend on the nature of the preceding workout – along the lines of the graphic below:</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=523&fit=crop&dpr=1 600w, https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=523&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=523&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=657&fit=crop&dpr=1 754w, https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=657&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/136049/original/image-20160831-29117-rhq5ly.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=657&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">University of Stirling</span></span>
</figcaption>
</figure>
<p>It is also worth pointing out that the <a href="http://www.acsm.org">American College of Sports Medicine</a>, the largest exercise science organisation in the world, specifically <a href="http://journals.lww.com/acsm-msse/Fulltext/2009/07000/Exercise_and_Physical_Activity_for_Older_Adults.20.aspx">recommends</a> that older adults perform full body resistance exercise workouts. </p>
<p>If our findings hold true for older adults, it may mean that they need to take even higher doses of protein to achieve optimal levels. Yet that might not be feasible for practical reasons – for example, you’d need to consume roughly two chicken breasts or about a litre of a thick shake to get 60g of protein. So instead of leading to changes in the nutrition, follow-up research may lead to older adults being recommended to change from performing a whole body routine to a split routine to maximise their muscle potential.</p><img src="https://counter.theconversation.com/content/64642/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Tipton has received funding from GSK Consumer Healthcare and the National Institutes for Health (USA). </span></em></p><p class="fine-print"><em><span>Lee Hamilton and Oliver Witard do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The advice on the sides of protein tubs may have to change.Lee Hamilton, Lecturer in Sport, Health and Exercise Science, University of StirlingKevin Tipton, Professor of Sport, Health and Exercise Sciences, University of StirlingOliver Witard, Senior Lecturer in Health & Exercise Science, University of StirlingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/628462016-07-27T10:31:33Z2016-07-27T10:31:33ZOld man strength: is dad really stronger?<figure><img src="https://images.theconversation.com/files/131382/original/image-20160721-32639-10ixkf1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&search_tracking_id=-gWPVSF9sbmrmQEfl6oFWQ&searchterm=strong%20old%20man&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=112493303">threerocksimages/Shutterstock</a></span></figcaption></figure><p>Sometimes, older men seem to possess incredible strength for their age. People call it “old man strength”. But is it an actual phenomenon? Do older guys really retain their strength? Or even get stronger?</p>
<p>Some people think that old man strength can be explained by stress hormones. In stressful situations, people have been know to develop almost superhuman strength. For example, in 2009, Nick Harris of Kansas managed to lift a car to free a six-year-old child <a href="http://www.kansas.com/news/local/article1018475.html">trapped beneath it</a>. </p>
<p>In these types of situations, the body goes into fight-or-flight mode by releasing hormones such as adrenaline. These hormones prepare the body for action, increasing arousal, alertness and processing speed. They also increase blood flow and neural drive to skeletal muscles. Collectively, this response can culminate in greater muscle strength and power. </p>
<p>Reports of increases in the <a href="http://www.ncbi.nlm.nih.gov/pubmed/10674429">production of adrenaline-related hormones with ageing</a> have been thought to explain the apparent ability of older men to perform <a href="http://www.mensfitness.com/training/build-muscle/whats-deal-old-man-strength,%20http://www.ncbi.nlm.nih.gov/pubmed/26400207">freak feats of strength</a>. However, there is no experimental data demonstrating that increased production of these hormones actually enhances strength in older adults. In fact, following a “stressor”, the ability for an older adult to maintain a controlled forceful muscle contraction is <a href="http://www.ncbi.nlm.nih.gov/pubmed/15220319">decreased compared with a younger person</a>. Similarly, excess levels of the <a href="https://en.wikipedia.org/wiki/Norepinephrine">noradrenaline</a> hormone that accompanies ageing are associated with impaired, rather than improved, processing speed and cognitive function, which <a href="http://www.ncbi.nlm.nih.gov/pubmed/23639207">negatively influences fine motor control</a>. </p>
<p>Also countering the notion of old man strength is age-related muscle loss, a process termed sarcopenia (from the Greek sarx, “flesh” and penia, “poverty”). In other words, as we get older, starting from about the age of 40, we <a href="http://www.ncbi.nlm.nih.gov/pubmed/22934016">slowly lose muscle mass</a> such that the size of our muscles at the age of 80 can be about half of what they were at 40. </p>
<p>Since muscle cross-sectional area and strength are <a href="http://www.ncbi.nlm.nih.gov/pubmed/11454977">closely linked</a>, declining muscle mass associated with ageing is mirrored by a loss of strength. Hormonal changes with ageing are also partially responsible for this. Indeed, while adrenaline may increase with age, hormones positively regulating muscle mass and strength, such as testosterone and growth hormone, decrease. </p>
<h2>So is old man strength a fallacy?</h2>
<p>This does not mean that just because you are old you cannot remain strong or even become stronger. Take Charles Eugster, for example. The 96-year-old Englishman, who took up weight training at the age of 87, is able to do 61 45-degree chin-ups in 45 seconds. </p>
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<p>Just becoming more active in older age and performing low-level exercise programmes or even everyday manual tasks can increase strength and mobility in the ageing population providing a <a href="http://www.ncbi.nlm.nih.gov/pubmed/26626157">healthy and independent older age</a>. Indeed, this is probably what makes your dad appear stronger, for instance, when lifting paving slabs – because he is used to it and strength can be very task specific. </p>
<p>Performing regular weight training into older age also increases strength and muscle bulk. In fact, weight training in older adults has been shown to increase hormone levels to an equivalent level to that of <a href="http://www.ncbi.nlm.nih.gov/pubmed/24443372">untrained younger adults</a>. But the fact remains that these gains will probably never reach those of a younger adult starting and performing the same training at the same time. There will almost always be a discrepancy in strength, power, coordination and muscle mass, all else being equal. </p>
<p><a href="https://www.youtube.com/watch?v=UI6bIptDffE">Media stories of old man strength</a> probably don’t provide the full picture. An older man holding a strength record is likely to have been training since a young age and has continued this into older age, allowing him to maintain strength and muscle mass at a higher level for longer. Otherwise he may be a freak of nature. </p>
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<img alt="" src="https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1006&fit=crop&dpr=1 754w, https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1006&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/131383/original/image-20160721-32602-w1kga1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1006&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Mark Felix: the World’s Strongest Man competitor, aged 50.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Mark_Felix#/media/File:Mark_Felix.jpg">Artur Andrzej/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Needless to say that most tales of old man strength are no doubt exaggerated. This is why you don’t see older people pitting against younger counterparts on an equal footing in athletics events and why we have age categories in athletic competitions: records tend to slide with age. There are of course, exceptions to every rule. A prime example of this is Mark Felix, who aged 50 is still able to compete with his considerably younger counterparts at the World Strongest Man competition.</p><img src="https://counter.theconversation.com/content/62846/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>What science can tell us about ageing and strength.Daniel J Wilkinson, Assistant Professor in Physiology and Biochemistry, University of NottinghamPhilip J Atherton, Professor of Clinical, Metabolic & Molecular Physiology, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.