tag:theconversation.com,2011:/fr/topics/protein-shakes-29053/articlesProtein shakes – The Conversation2022-02-03T09:50:18Ztag:theconversation.com,2011:article/1733912022-02-03T09:50:18Z2022-02-03T09:50:18ZPre-workout supplements: why five of the six most common ingredients probably aren’t helping you<figure><img src="https://images.theconversation.com/files/443427/original/file-20220131-125257-611aq8.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5751%2C3837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A lack of research means we still know very little about whether pre-workout supplements work.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/workout-woman-pink-top-drinking-energy-1812888592">Stockmedia Sweden/ Shutterstock</a></span></figcaption></figure><p>When it comes to getting in shape, many people are willing to try any tricks they need to reach their goals faster. For many years, protein shakes were seen as essential after a workout. But more recently, in addition to protein shakes, many are also turning to pre-workout supplements. These are marketed as being able to enhance your workout by increasing energy, boosting metabolism and improving muscle growth. They’re usually taken as a tablet or consumed as a drink around 30-45 minutes before a workout.</p>
<p>But despite the high demand for pre-workout supplements, the lack of research, variations in the products, and uncertainty about what they contain makes it difficult for consumers to understand how effective they really are – and whether they do what they claim.</p>
<p>Here we take a look at some of the most common pre-workout ingredients to see whether there’s any evidence they work.</p>
<h2>Caffeine</h2>
<p>Caffeine is typically added to most pre-workout supplements as a stimulant to reduce fatigue and increase alertness. There’s good evidence showing that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4213371/">consuming caffeine</a> around 30-60 minutes before exercise can improve endurance performance (such as running or cycling) typically by as much as 20% during exercise lasting one to two hours. It may also make your workout feel slightly less difficult. </p>
<p>The main downside of caffeine is that high doses (between 5-13 milligrams of caffeine per kilogram of body weight – so around 375mg-975mg for a 75kg person) have reported side-effects, such as an upset stomach, confusion and poor sleep. For perspective, a single espresso shot only contains about 75mg of caffeine. But <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4213371/">smaller doses</a> (around 3mg per kg of body weight) have still been shown to be effective with fewer or no side-effects. Most pre-workout supplements contain between 85mg-300mg of caffeine.</p>
<p>It might seem easier to simply drink coffee before exercise, but depending on where your coffee comes from, the caffeine content can <a href="https://pubmed.ncbi.nlm.nih.gov/14607010/">vary considerably</a>. This may mean that you have either too much, or not enough, whereas a set dose from a supplement can be easily controlled.</p>
<h2>Beta-alanine</h2>
<p>Beta-alanine is an amino acid that your body naturally produces. It works together with other chemicals in the body to produce a substance called carnosine. Carnosine is stored in your muscles, and is an important factor in maintaining the pH level of the muscle – which can be important in delaying fatigue during high intensity exercise.</p>
<p>For this reason, beta-alanine is added to many pre-workout supplements to reduce fatigue. However, while there is some evidence that taking beta-alanine supplements can work, at least 3.6 grams would need to be <a href="https://bjsm.bmj.com/content/51/8/658.long">taken daily</a> for up to six weeks to have any effect – and most pre-workout supplements only contain around 350mg-3,200mg. There’s no evidence that taking small amounts before a workout has any effect, apart from the tingling side effect that can occur in some people, which may make them think it’s working.</p>
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<img alt="A woman holding a pre-workout shake in a plastic bottle looks at the smart watch on her wrist." src="https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443430/original/file-20220131-15-dhoq7a.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">There’s currently no evidence taking beta-alanine before a workout works.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/keep-calm-train-more-woman-relaxing-1510484741">Adamov_d/ Shutterstock</a></span>
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<h2>Branched-chain amino acids</h2>
<p>Branched-chain amino acids (also known as BCAAs) are another common ingredient. We usually obtain them from foods like dairy, meat and legumes, and they are added to pre-workout supplements to promote muscle growth and reduce fatigue. </p>
<p>Most pre-workouts contain around 400mg-1500mg of BCAAs. But at these levels, there’s little evidence they’re effective in promoting muscle growth or reducing fatigue. In fact, BCAAs typically need to be taken at much higher doses (around 5,000mg) <a href="https://www.frontiersin.org/articles/10.3389/fphys.2017.00390/full">after exercise</a> to promote muscle growth and repair.</p>
<h2>Creatine</h2>
<p>Creatine monohydrate is a chemical found naturally in our body, as well as in foods such as red meat and seafood. Many pre-workout products contain creatine because it’s thought to increase muscle size and strength. </p>
<p>While lots of research shows that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469049/">creatine is beneficial</a> for improving many aspects of performance – such as how many sprints you can do, muscle strength and how quickly you can recover after a workout – at least 3g-5g needs to be taken daily to be effective. </p>
<p>Evidence also shows that initially taking 20g of creatine for five days, followed by a maintenance dose of 3g-5g per day will <a href="https://www.sciencedirect.com/science/article/pii/S0955286397001162">improve athletic performance</a>. However, taking small doses before exercise is not shown to have any benefit. Pre-exercise supplements contain around 1.5g-5g per serving – so if you take a large amount initially, they may have some effective thereafter.</p>
<h2>Green tea</h2>
<p>Green tea extract is usually added to pre-workouts in order to reduce body fat. Pre-workout supplements that contain green tea typically contain around 100mg-250mg. </p>
<p>There’s limited evidence that green tea has any effect at such low doses. Results are also mixed even when looking at <a href="https://jissn.biomedcentral.com/articles/10.1186/s12970-014-0062-7">high doses</a> (around 300mg-600mg) taken over a <a href="https://academic.oup.com/jn/article/145/5/864/4644393">long period</a> of time.</p>
<h2>B vitamins</h2>
<p>B vitamins are typically found in foods such as fish, chicken and dairy. Many pre-workout supplements contain B vitamins because they help us produce energy, which can of course help us perform better during a workout.</p>
<p>But unless a person is deficient in these vitamins, it’s unlikely that taking a product which contains them will have any benefit – although exercise may <a href="https://pubmed.ncbi.nlm.nih.gov/17240780/">increase the need</a> for some B vitamins, especially B2 and B6. </p>
<p>Most of the ingredients found in pre-workout supplements are shown to be safe at the low doses they’re typically included in. However, taking them late in the day may be a bad idea, as the caffeine in them could disrupt sleep. </p>
<p>But of major concern are some of the novel ingredients included in some supplements as they often haven’t been studied or tested as well as other ingredients. In some cases, they may even cause serious problems, such as <a href="https://pubmed.ncbi.nlm.nih.gov/19058338/">liver damage</a>. So checking with a registered sports nutritionist or dietician before taking a supplement is a good idea.</p>
<p>Despite pre-workout supplements being one of the fastest growing sports supplements, aside from caffeine there are not many ingredients that are consistently effective for improving athletic performance when taken in small doses before a workout.</p><img src="https://counter.theconversation.com/content/173391/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Graeme Close receives funding from from a variety of sports nutrition companies including Healthspan Elite, Get Buzzing, Gatorade (GSSI), NutritionX, Naturecan, Aliment Nutrition and GSK, and has received research grants from BBSRC and the MRC. He is affiliated with NutritionX as their scientific advisor. None of these organisations had any input into this Conversation piece.</span></em></p><p class="fine-print"><em><span>Andy Sparks has received research funding from a variety of nutrition companies including AstaReal, Capsugel, Nephcentric, NutriProt, and VitaFoods Europe. None of these organisations had any input into this Conversation piece.</span></em></p>There’s little evidence that the ingredients in most of these supplements work at the small doses they’re normally taken.Graeme Close, Professor of Human Physiology, Liverpool John Moores UniversityAndy Sparks, Reader in Exercise Physiology, Edge Hill UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/825322017-08-17T15:15:22Z2017-08-17T15:15:22ZIs it safe to take exercise supplements?<figure><img src="https://images.theconversation.com/files/182392/original/file-20170817-13501-1c6wicq.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/512787562?src=Z2-v3aTNNNh5LbScYLSSXQ-1-78&size=medium_jpg">naito29/Shutterstock</a></span></figcaption></figure><p>An <a href="http://edition.cnn.com/2017/08/15/health/australian-body-builder-death-protein-shakes/index.html">Australian woman</a> with a genetic disorder died from consuming too many protein supplements, it was recently reported. The woman in question, Meegan Hefford, a 25-year-old bodybuilder, suffered from a rare, undiagnosed disorder that caused a fatal build-up of ammonia in her body (ammonia is produced when the body breaks down protein). This raises the question: are exercise supplements safe? </p>
<p>In healthy people, most commonly used supplements intended to enhance the body – often referred to in the scientific literature as “nutraceuticals” or “functional foods” – are harmless. Nonetheless, there are rare cases where underlying health conditions or excessive consumption could cause ill health.</p>
<p>By far the most common supplement taken by gym goers are those containing amino acids in the form of protein, protein hydrolysates (such as whey protein), or individual branched chain amino acids (BCAA), containing leucine, isoleucine and valine. People take these supplements to support muscle building on the premise that amino acids are the building blocks of muscle tissue. Aside from the rare genetic disorder suffered by Meegan Hefford, are there any dangers to consuming these protein supplements? </p>
<p>There are a number of other very rare genetic disorders where handling of certain amino acids is compromised. For example, maple syrup urine disease (MSUD) leads to a toxic build-up of the BCAA <a href="https://www.ncbi.nlm.nih.gov/pubmed/15930470">making their over consumption dangerous</a>. Nonetheless, sufferers of MSUD are typically diagnosed at an early age, so this is unlikely to manifest through excessive protein intake in adulthood. </p>
<p>As well as genetic disorders of amino acid handling, people with kidney disease are often told to avoid high protein diets, since excess intake can strain failing kidneys. It is this that led to the premise that high protein diets and, by extension, protein supplements are “bad for the kidneys”. </p>
<p>But this has now largely been <a href="http://jn.nutrition.org/content/142/12/2220S">debunked</a>, since athletes consuming nearly 3g per kilogram of bodyweight per day (about three-and-a-half times the recommended daily allowance of 0.8g/kg/day) and healthy adults consuming up to 1.25g/kg/day of leucine show very <a href="http://jn.nutrition.org/content/142/12/2225S.full.pdf+html?sid=99e374e7-24f7-4b71-bb6d-a423a3b2c4a7">few negative health effects</a>, at least in the medium term. So, apart from in extremely rare cases, taking protein supplements is generally safe.</p>
<h2>L-carnitine and creatine</h2>
<p>While too numerous to mention, there are a wealth of supplements being consumed by gym goers, with the aim of enhancing muscle mass, reducing fat and increasing performance. Let’s have a look at their safety.</p>
<p>Both L-carnitine and creatine are naturally occurring compounds taken to improve muscle mass, performance or weight loss. (Red meat is particularly rich in these substances.) As with most supplements, these supplements have been subject to many investigations as to their safety. To date, there is minimal evidence that they are harmful to humans, despite early claims of potential liver or kidney damage, muscle cramps or electrolyte imbalances. Also, there are no known underlying diseases which could make them dangerous. </p>
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<img alt="" src="https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182403/original/file-20170817-13487-1fnd87h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&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">Red meat is rich in L-carnitine and creatine.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/194313791?src=B8wFhoWuLtH5y_WVqgzkTQ-1-0&size=medium_jpg">hlphoto/Shutterstock</a></span>
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<h2>Conjugated linoleic acids</h2>
<p>Conjugated linoleic acids (CLA) are another popular supplement. CLA is a specific type of fat that is associated with decreases in fat mass and increases in muscle mass. While generally thought to be safe, there is <a href="https://www.ncbi.nlm.nih.gov/pubmed/20140250">data</a> from animal models and in humans suggesting their consumption can lead to unfavourable changes in the blood, namely increases in low density lipoproteins (“bad fats”). As is always the case, long-term data from controlled trials is unavailable, so there will always be an element of doubt over their safety.</p>
<h2>Vitamin E and resveratrol</h2>
<p>But there are other considerations surrounding potentially harmful effects of supplements. A recent example of this are antioxidant supplements, such as vitamin E and reseveratrol. Indeed, while early work purported that these supplements could enhance exercise performance, it later became apparent that, if anything, they could <a href="http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2013.258061/abstract">work against</a> the <a href="https://www.ncbi.nlm.nih.gov/pubmed/19433800">beneficial effects of exercise</a>. </p>
<h2>Contamination</h2>
<p>Also, rather than the nutrient supplemented being harmful itself, there may be other contaminating compounds within the supplement, unknown to the consumer, that could potentially cause harm. </p>
<p>We often hear news stories about failed drug tests in sport being caused by “contaminated supplements”. Whether this is true or not, there remains real and troubling <a href="http://www.sciencemag.org/news/2015/08/feature-revealing-hidden-dangers-dietary-supplements">evidence of contamination</a> within dietary supplements by a number of different controlled substances. Indeed, with control over their production lacking in pharmaceutical rigour, there may be unknown dangers in supplements, particularly those purchased online. A <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6240a1.htm">recent case</a> from the US highlights these dangers where a number of people suffered severe acute hepatitis and fulminant liver failure after consuming the same dietary supplement, OxyELITE Pro. </p>
<p>So, while there are few risks to taking supplements (or at least a lack of evidence that they are harmful), it should be remembered that some supplements could negatively affect what people are trying to achieve. Or they could be contaminated to make them appear like “wonder supplements”. </p>
<p>Also, the true efficacy of many emerging supplements is lacking – often being more based on theory and marketing than reproducible science. That being said, a <a href="https://www.ncbi.nlm.nih.gov/pubmed/28143855">small number of supplements</a> do have proven beneficial effects alongside exercise and moreover many of these have translated into proven clinical benefits . </p>
<p>Going back to protein supplements, yes, they can <a href="https://www.ncbi.nlm.nih.gov/pubmed/28698222">enhance muscle-mass with exercise</a>, though the effect is small, and supplements could easily be replaced by changes to diet.</p><img src="https://counter.theconversation.com/content/82532/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>An Australian woman recently died as a result of taking too much protein supplement. But that doesn’t mean these sorts of supplements should be avoided.Philip J Atherton, Professor of Clinical, Metabolic & Molecular Physiology, University of NottinghamDaniel J Wilkinson, Assistant Professor in Physiology and Biochemistry, University of NottinghamLicensed 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>
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<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>
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<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>
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<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>
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</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/614662016-07-06T14:50:21Z2016-07-06T14:50:21ZMuscle-building shakes don’t always have as much protein as they claim to<figure><img src="https://images.theconversation.com/files/129374/original/image-20160705-804-othfdk.jpg?ixlib=rb-1.1.0&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>Protein supplements have become a <a href="http://www.nutritionexpress.com/showarticle.aspx?articleid=1760">widely popular</a> way for avid gym-goers to pump extra protein into their bodies and bump up their muscles.</p>
<p>Protein is essential for the <a href="http://www.webmd.com/men/features/benefits-protein">overall health</a> of the body, building and repairing its tissues and balancing the levels of energy, hormones and many other chemicals. It’s also central in building muscles – often the attraction for its use in body building and fitness products.</p>
<p>Ideally men should get about 56g of protein a day for their normal body processes to continue. Women, it is <a href="http://fnic.nal.usda.gov/dietary-guidance/dri-nutrient-reports/energy-carbohydrate-fiber-fat-fatty-acids-cholesterol-protein">recommended</a>, should have about 46g of protein. </p>
<p>An <a href="http://www.sajcn.co.za/index.php/SAJCN/article/view/747/1079">egg</a> contains about 6g of protein, while a portion of soybeans (half a cup) could contain 15g of protein and one <a href="http://www.ajol.info/index.php/sajas/article/view/121445/110910">lean lamb loin chop</a> could contain 14g of protein. </p>
<p>There has been much debate around people pumping protein supplements into their bodies. <a href="http://www.uni.edu/dolgener/Advanced_Sport_Nutrition/protein_intake.pdf">Some research</a> suggests that people who are undergoing muscle-building training need higher quantities of protein to support maximum muscle growth. But there is <a href="https://www.ncbi.nlm.nih.gov/pubmed/7550257">no scientific agreement</a> that these people really need to consume more protein than the <a href="http://fnic.nal.usda.gov/dietary-guidance/dri-nutrient-reports/energy-carbohydrate-fiber-fat-fatty-acids-cholesterol-protein">recommended dietary allowance</a>. </p>
<p>Yet weight trainers and sportspeople <a href="http://ajcn.nutrition.org/content/72/2/551s.full">often</a> supplement their diets with protein shakes or bars. This could be due to their convenience – they cost less than meat products with the same protein content, and they allow for optimal protein intake without excessive consumption of carbohydrates or fats.</p>
<p>But <a href="http://dischem.co.za/articles/15187-sport-supplements/20742-short-report-understanding-label-compliance-of-high-protein-sports-supplements-to-inform-regulations">our study</a> has found that, when it comes to protein shakes, what is in the tub is not always what meets the eye. Close to 10% of protein shakes evaluated on the market had less than 60% of the amount of protein consumers were paying for.</p>
<h2>The making of a protein supplement</h2>
<p>Protein supplements come in the form of shakes, bars and other meal replacement products. Protein powders are the <a href="http://journals.humankinetics.com/AcuCustom/Sitename/Documents/DocumentItem/2755.pdf">most popular</a>. These powders are usually mixed with water or milk to form a shake that should be consumed immediately before or after exercise, or in the place of a regular meal.</p>
<p>The protein components in these powders are often derived from dairy (whey or casein) or soy. The powders often contain other ingredients, such as flavouring and non-nutritive sweeteners for improved taste. </p>
<p>Our <a href="http://dischem.co.za/articles/15187-sport-supplements/20742-short-report-understanding-label-compliance-of-high-protein-sports-supplements-to-inform-regulations">study</a> looked at the label compliance of protein supplements in South Africa. We analysed 70 products purchased at popular South African retailers and online stores.</p>
<p>We selected two samples from different batches of each product and sent these for nutritional analyses. This would determine the actual nutrients present in the product through <a href="http://www.csir.co.za/food_and_beverage/">accredited methods</a>. And these nutrient values were then compared with the values reported on the product labels.</p>
<p><a href="http://www.sanbwa.org.za/documents/Guidelines.pdf">Regulations</a> around the labelling and advertising of foodstuffs allow for a 25% difference between the actual content of the product and that printed on the label.</p>
<p>In our study we found a difference of up to 80% in the labelled protein content and the value determined during analysis. From the 70 products included in the study, 65 products – or 93% – fell within the regulations.</p>
<p>In 21 products the actual protein in the product was more than 10% less than that stated on the label, but five products over-reported protein content by more than the acceptable limit of 25%. </p>
<p>These five products had between <a href="http://dischem.co.za/protein-content-of-supplements-as-analysed-compared-to-label-declaration">42% and 80% less protein</a> in the tub than what they declared on their product labels. </p>
<h2>A change of plan</h2>
<p>Our study comes amid discussion around the placement of sports supplements in the current South African legislative framework. The South African National Department of Health’s <a href="http://www.thefoodsafetynetwork.co.za/images/stories/docs/consumers/Directorate_Food_Control_information.pdf">Directorate: Food Control</a> and the <a href="http://www.mccza.com/About">Medicines Control Council</a> are negotiating amendments to their regulations. </p>
<p>The general discussion is that products – such as protein shakes – which are pills, jellies and tablets will in future be labelled as foods and fall under the jurisdiction of the <a href="http://www.gov.za/sites/www.gov.za/files/37695_rg10205_gon429.pdf">regulations relating to foods</a>. </p>
<p>But food that makes a medicinal claim will fall under the <a href="http://www.hpcsa.co.za/Uploads/editor/UserFiles/downloads/legislations/acts/medicines_and_related_sub_act_101_of_1965.pdf">Medicines Act</a> as a complementary medicine. </p>
<p>Should protein shakes fall under the Medicines Act, the leeway manufacturers will have in terms of the difference between protein stated on a label and found in a product would be reduced from 25% to 10%. </p>
<p>In the US, fortified or fabricated foods with added nutrients are deemed misbranded under sections of the <a href="http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.9">Federal Food, Drug, and Cosmetic Act</a> if the protein content of the product is not at least equal to, or more than, the value declared on the product label. These violations are subject to <a href="http://definitions.uslegal.com/m/misbranded-food/">civil penalties</a>. </p>
<p>In <a href="http://www.foodstuffsa.co.za/news-stuff/food-labelling-regulations/3089-new-labelling-regs-a-wrap-of-r146-a-year-on">South Africa</a> a guilty party can be fined up to R20,000 for a first offence. </p>
<h2>The next steps</h2>
<p>After establishing the differences in the total protein content listed on the labels of products and the measured values, researchers are now looking at the integrity of the protein. </p>
<p>Many protein shakes claim the presence of certain essential protein fragments such as branched-chain amino acids or individual amino acids on their labels. <a href="http://www.aminoacid-studies.com/amino-acids/what-are-amino-acids.html">Amino acids</a> are the building blocks of protein. Certain amino acids, which are considered to be inferior to whole proteins, have been used by some manufacturers to artificially inflate and falsify higher total protein values in their products, commonly referred to as <a href="http://www.jimstoppani.com/home/articles/protein-spiking?preview">protein spiking</a>. Many protein supplements explicitly state on their labels that they do not spike.</p>
<p>The next step is to determine the amino acid profile of these protein shakes and to compare this with the claims made on the product labels.</p><img src="https://counter.theconversation.com/content/61466/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Prof Hettie Schönfeldt was the lead researcher on the project which was commissioned and financed by Dis-Chem Pharmacies South Africa with the aim to increase responsible retailing of supplements and assist in informing national regulatory developments. </span></em></p><p class="fine-print"><em><span>The research was commissioned and funded by Dis-Chem Pharmacies South Africa with the aim to increase responsible retailing of supplements and assist in informing national regulatory developments. </span></em></p><p class="fine-print"><em><span>Beulah Pretorius 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>Protein supplements are all the rage for fitness fanatics and those hoping to boost their muscles – but do they contain as much protein as they claim to?Hettie Carina Schönfeldt, Associate Professor of Human Nutrition at the Institute of Food, Nutrition and Wellbeing, University of PretoriaBeulah Pretorius, Reseacher in Human Nutrition and Food Composition, University of PretoriaNicolette Hall, Researcher in Human Nutrition, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.