tag:theconversation.com,2011:/global/topics/sport-and-exercise-137/articlesSport and exercise – The Conversation2024-02-21T13:19:09Ztag:theconversation.com,2011:article/2161252024-02-21T13:19:09Z2024-02-21T13:19:09ZYour heart changes in size and shape with exercise – this can lead to heart problems for some athletes and gym rats<p>Exercise has long been recognized by clinicians, scientists and public health officials as an <a href="https://www.nhlbi.nih.gov/health/heart/physical-activity/benefits">important way to maintain health</a> throughout a person’s lifespan. It improves overall fitness, helps build strong muscles and bones, reduces the risk of chronic disease, improves mood and slows physical decline. </p>
<p>Exercise can also significantly reduce the risk of developing conditions that negatively affect heart heath, such as high blood pressure, high cholesterol and obesity. But large amounts of exercise throughout life may also harm the heart, leading to the development of a condition called <a href="https://www.merckmanuals.com/professional/cardiovascular-disorders/sports-and-the-heart/athlete%E2%80%99s-heart">athletic heart</a>.</p>
<p>As the <a href="https://medschool.cuanschutz.edu/cardiology/clinical-programs/multidisciplinary-programs/sports-cardiology">sports cardiology director</a> at the University of Colorado Anschutz Medical Campus, I’m often asked how much and what kind of exercise is necessary to get the benefits of exercise. Many people also wonder about the risks of exercise, and what happens if you exercise too much. </p>
<p>The <a href="https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults">American Heart Association generally recommends</a> 150 minutes of moderate-intensity exercise, such as brisk walking, or 75 minutes of vigorous-intensity exercise, such as running, each week. It also recommends muscle strengthening exercises at least twice per week.</p>
<p>When people exceed these guidelines, the heart may remodel itself in response – that is, it begins to change its size and shape. As a result, heart function may also change. These changes in heart structure and function among people who engage in high levels of exercise are referred to as the athletic heart, or athlete’s heart. Athletic heart doesn’t necessarily cause problems, but in some people it can increase the risk of certain heart issues.</p>
<h2>What is athletic heart?</h2>
<p>To understand how exercise affects the heart, it’s important to consider what kind of exercise you’re participating in. </p>
<p>Exercise is generally divided into <a href="https://doi.org/10.1016/j.jacc.2015.09.033">two broad categories</a>: dynamic and static. </p>
<p>Dynamic exercises, like running, cross-country skiing and soccer, require the heart to pump an increased amount of blood, compared to the amount delivered to the body at rest, in order to sustain the activity. For example, when running, the amount of blood the heart pumps to the body may increase by threefold to fivefold compared to at rest.</p>
<p>Static exercises, like weightlifting, gymnastics or rock climbing, require the body to use skeletal muscle in order to push or pull heavy amounts of weight. While the heart does pump more blood to skeletal muscles that are working during these activities, these kinds of exercises depend on a muscle’s ability to move the weight. For example, in order to do curls with dumbbells, the biceps must be strong enough to lift the desired weight. </p>
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<a href="https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up of lower half of the back of a person cycling, one hand outstretched towards the vegetation on the side of the road" src="https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576223/original/file-20240216-28-rwjbi1.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>
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<span class="caption">Cycling involves both dynamic and static exercise.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/man-in-black-shorts-riding-bicycle-on-road-during-daytime-vRuoDd-Qnq8">Judit Murcia/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Some exercises, like rowing or cycling, are both highly dynamic and highly static because they require the heart to pump large amounts of blood while simultaneously requiring a large amount of muscle strength to sustain effort.</p>
<p>It is important to distinguish between dynamic and static exercise because the heart adapts differently according to the type of exercise you engage in over time. Dynamic exercise increases the volume of blood pumping through the heart and can cause the heart to become enlarged, or dilated, over time. Static exercise increases the amount of pressure on the heart and can also cause it to become enlarged over time but with thickened walls.</p>
<h2>Who develops athletic heart?</h2>
<p>Exercise that exceeds guidelines, such as exercising more than an hour most days of the week, may lead to development of athletic heart. Athletic heart commonly occurs <a href="https://doi.org/10.1161/01.CIR.101.3.336">among endurance athletes</a>, who regularly compete in activities like marathons or other long-duration events. Many exercise several hours per day and more than 12 to 15 hours per week.</p>
<p>Among runners, for example, the heart remodels itself in response to having to pump a high volume of blood. As a result, the chambers of the heart enlarge to hold and pump more blood. Among weightlifters, the heart remodels itself by thickening in response to the increase in pressure applied on the heart.</p>
<p>Exercise is good for the body, and athletic heart results from a lifelong commitment to an activity that promotes good health. But there may be some issues that arise from an athletic heart.</p>
<p>First, athletes with markedly enlarged hearts may be at risk of developing <a href="https://www.acc.org/Latest-in-Cardiology/Articles/2019/08/16/08/20/Atrial-Fibrillation-in-Competitive-Athletes">atrial fibrillation</a>, which is abnormal heart rhythms that typically occur among older adults or people with high blood pressure or heart failure. Abnormal heart rhythms are worrisome because they may lead to a stroke. </p>
<p>There are many potential reasons atrial fibrillation occurs in athletes. A dilated atrium – the top chamber in the heart – may become inflamed and develop scar tissue, increasing the risk of atrial fibrillation. <a href="https://doi.org/10.1161/01.CIR.0000031733.51374.C1">Stress and environmental factors</a> may also work together to increase the risk of arrhythmia.</p>
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<a href="https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Clip of an ultrasound reading of an enlarged heart beating" src="https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=537&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=537&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=537&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=675&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=675&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576219/original/file-20240216-28-p2nrzu.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=675&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">This is an echocardiogram of a 30-year-old athlete with an enlarged heart.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:4_chamber_(1).gif">Runandbike/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><a href="https://doi.org/10.1161/CIRCULATIONAHA.117.027834">Coronary artery calcification, or CAC</a>, is another concern among elite athletes. Coronary artery calcification, which commonly occurs in older adults or those with risk factors for coronary artery disease, increases the risk of having a heart attack or stroke. In recent years, doctors have been using imaging tests to monitor calcium buildup in the arteries of their patients to try to determine their risk of heart attack or stroke over time.</p>
<p>It is not entirely clear why elite athletes develop coronary artery calcification. Fortunately, it does not appear that athletes have an increased risk of heart attack, even among those with very high levels of CAC. For example, a large study of almost 22,000 participants found that even athletes who engaged in high amounts of exercise and had elevated levels of CAC <a href="https://doi.org/10.1001/jamacardio.2018.4628">did not have an increased risk</a> of death from cardiovascular disease over a decade of follow-up.</p>
<p>Some athletes are appropriately concerned about having calcium buildup in their heart arteries and may wonder whether or not they should be taking medications like aspirin or statins. But risks <a href="https://doi.org/10.1016/j.mayocpiqo.2019.03.007">vary from person to person</a>, so anyone concerned about CAC should talk to their doctor</p>
<h2>Putting exercise in its place</h2>
<p>Though elite athletes may have an increased risk of developing athletic heart, exercise undoubtedly remains one of, if not the best, methods to maintain a healthy lifestyle.</p>
<p>For example, if someone does not exercise routinely, their heart <a href="https://doi.org/10.1161/circulationaha.105.541078">will become stiff</a> and not pump blood as well as it once did. Routine exercise – especially dynamic exercise like running – maintains a compliant heart and prevents stiffening. A compliant heart will expand a lot more as it fills with blood and, in turn, pump out more blood with each heartbeat. A stiff heart has difficulty filling up with blood and has difficulty pumping blood through the body.</p>
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<a href="https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two people running on a road lined with trees -- the younger person is trailing behind the older person who has leaped into the air with arms raised" src="https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576226/original/file-20240216-24-i1u421.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&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">Regular exercise can help keep your heart young.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/the-old-and-young-sportsmen-running-on-the-road-royalty-free-image/1086683052">Viacheslav Peretiatko/iStock via Getty Images Plus</a></span>
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<p>Generally, routine exercise throughout adulthood encourages the heart to <a href="https://doi.org/10.1016/j.jacc.2014.03.062">remain strong and flexible</a> even in old age. Even if someone were only to begin regularly exercising in their 40s to 50s, it is possible to <a href="https://doi.org/10.1161/circulationaha.117.030617">reverse some of the effects</a> of sedentary aging.</p>
<p>For example, a 2018 study of 53 sedentary people mostly in their early 50s found that those who participated in a two-year exercise training program using a combination of running, cycling and elliptical exercise had hearts that <a href="https://doi.org/10.1161/circulationaha.117.030617">became more compliant</a> compared to the hearts of those who did not exercise.</p>
<p>It is never too late to start exercising. Routinely following exercise guidelines can help promote physical and mental health and help your heart stay young throughout your life.</p><img src="https://counter.theconversation.com/content/216125/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William Cornwell 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>People who regularly engage in significant amounts of exercise, as endurance athletes do, may develop enlarged hearts. While athletic heart is adapted for performance, it can be cause for concern.William Cornwell, Associate Professor of Cardiology, University of Colorado Anschutz Medical CampusLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2197962023-12-18T22:48:17Z2023-12-18T22:48:17Z‘Politically neutral’ Russian athletes can now enter the Olympics – but don’t expect many to compete<p>Earlier this month, the International Olympic Committee (IOC) announced Russian and Belarussian athletes <a href="https://olympics.com/ioc/news/strict-eligibility-conditions-in-place-as-ioc-eb-approves-individual-neutral-athletes-ains-for-the-olympic-games-paris-2024">will be able to compete</a> in the 2024 Paris Olympics if they are politically neutral. The decision from the committee’s executive board reversed an earlier ban. </p>
<p>The IOC made this change even though the Russian National Olympic Committee remains suspended from competition for its <a href="https://olympics.com/ioc/news/ioc-executive-board-suspends-russian-olympic-committee-with-immediate-effect">violation</a> of “the territorial integrity of the National Olympic Committee of Ukraine”. For its part, Russia <a href="https://www.npr.org/2023/12/09/1218406353/russian-belarus-athletes-ioc-2024-olympic-games">rejects</a> the decision.</p>
<p>The committee’s decision has enraged Western leaders, particularly those in Ukraine. Ukrainian Foreign Minister Dmytro Kuleba <a href="https://www.insidethegames.biz/articles/1142889/kyiv-says-ioc-encouraging-war-ukraine">accused</a> the committee of effectively giving “[…] Russia the green light to weaponize the Olympics”.</p>
<p>While it might seem like a good idea not to hold individual athletes responsible for the decisions of governments, the decision is more complicated that it appears.</p>
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<a href="https://theconversation.com/refugee-team-offers-a-way-for-russian-and-belarusian-dissidents-to-compete-at-the-paris-olympics-202427">Refugee team offers a way for Russian and Belarusian dissidents to compete at the Paris Olympics</a>
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<h2>Athletes caught in the middle</h2>
<p>More than 30 Western nations, including Australia, <a href="https://www.theguardian.com/sport/2023/dec/08/athletes-who-have-not-supported-ukraine-war-to-compete-at-paris-2024">have previously called for</a> a complete ban on Russian participation in the Games. </p>
<p>IOC President Thomas Bach <a href="https://www.bbc.com/news/world-europe-67711799">defended his decision</a> by arguing “individual athletes cannot be punished for the acts of their governments”. </p>
<p>The ruling came with <a href="https://olympics.com/ioc/news/strict-eligibility-conditions-in-place-as-ioc-eb-approves-individual-neutral-athletes-ains-for-the-olympic-games-paris-2024">strict conditions</a>. Athletes must not be open supporters of the Russian invasion and they cannot be affiliated with Russian or Belarussian military or security services.</p>
<p>They cannot compete under their home country’s flag, or with national emblems or anthems.</p>
<p>The committee estimates that only 11 athletes – six Russians and five Belarussians – will qualify under these regulations.</p>
<p>The committee has been <a href="https://www.bbc.com/sport/olympics/64604212">slowly working towards this policy</a> since the spring of 2023. </p>
<p>The call may seem reasonable. After all, why should Russian and Belarussian athletes, especially those not supportive of the invasion, suffer from the actions of their government?</p>
<p>But it’s not quite that cut and dry.</p>
<h2>Different, inconsistent approaches</h2>
<p>The rule change seems inconsistent. As the committee continues to ban the participation of Russian teams, not all neutral Russian and Belarussian athletes will be able to participate. </p>
<p>Sporting federations can also continue to ban Russian and Belarussian athletes from competition and therefore qualification for the Games. World Athletics President <a href="https://news.yahoo.com/world-athletics-defies-ioc-maintains-113900349.html?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8&guce_referrer_sig=AQAAAK8RYILhtTwcf8F72FRd3jOng0u7BeehrhgaTPszxpb7HT9ufXfwDnRCQSfZc9McQRQCjCxxmdsURC3tDSmswrm1A60uNAT8dg">Seb Coe confirmed</a> that the organisation will continue to ban them. </p>
<p>By contrast, World Taekwondo and World Judo have both allowed Russian and Belarussian athletes to <a href="https://olympics.com/ioc/media/q-a-on-solidarity-with-ukraine-sanctions-against-russia-and-belarus-and-the-status-of-athletes-from-these-countries">compete in qualification</a>.</p>
<p>In September, the International Paralympic Committee also decided neutral athletes <a href="https://www.paralympic.org/news/ipc-general-assembly-partially-suspends-npc-russia">can compete</a>.</p>
<h2>What can Ukraine’s allies do?</h2>
<p>With the Paris 2024 games only seven months away, the IOC’s decision seems final. But frustrated Western leaders have other options. </p>
<p>In the past year, Western officials have <a href="https://www.euronews.com/2023/03/30/paris-olympics-if-russian-athletes-are-cleared-to-compete-will-a-boycott-threat-have-any-e#:%7E:text=Ukraine%20has%20threatened%20to%20boycott,the%202024%20Paris%20Olympic%20Games.">threatened to boycott</a> the Olympics if Russian and Belarussian athletes competed. </p>
<p>There is a long history of politically motivated Olympic boycotts and threatened boycotts. In 1980, the United States and 66 other countries boycotted the Moscow games <a href="https://www.washingtonpost.com/world/2021/12/08/history-olympic-games-boycotts/">in response to the Soviet Invasion of Afghanistan</a>. Eight other countries, including Australia, competed under an Olympic flag to signal their opposition to the invasion. </p>
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Read more:
<a href="https://theconversation.com/in-a-year-of-sporting-mega-events-the-brisbane-olympics-can-learn-a-lot-from-the-ones-that-fail-their-host-cities-187838">In a year of sporting mega-events, the Brisbane Olympics can learn a lot from the ones that fail their host cities</a>
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<p>In 1984, in response, the Soviet Union and its allies boycotted the summer Olympics in Los Angeles. </p>
<p>A boycott of the Paris Olympics would be devastating to the organisers, but it remains very unlikely. France is a Western nation and a strong supporter of Ukraine. President Emmanuel Macron recently <a href="https://www.barrons.com/news/eu-should-give-ukraine-full-and-enduring-support-macron-65f3b496?refsec=topics_afp-news">encouraged the European Union</a> to continue supporting the beleaguered nation.</p>
<p>As a more palatable approach, Western leaders could ban athletes from Russia and Belarus from competing in international athletic competitions in Western Europe in the run-up to the games. This would likely make it impossible for any athletes from those countries to qualify for spots in Paris. </p>
<p>As historian Heather Dichter <a href="https://muse.jhu.edu/pub/190/monograph/chapter/3034403">has shown</a>, travel bans have a long history in the Olympics. </p>
<p>In the 1960s, there was a <a href="https://members.shafr.org/assets/docs/Passport/2022/September-2022/passport-09-2022-dichter.pdf">NATO-wide ban on East German athletes</a> travelling to compete in events in Western European countries. This effectively barred them from participation in several major sporting competitions and from qualifying for the Olympics. </p>
<p>Some Western leaders have already attempted to use this strategy against Russian and Belarussian athletes. Polish President Andrzej Duda <a href="https://olympics.com/ioc/media/q-a-on-solidarity-with-ukraine-sanctions-against-russia-and-belarus-and-the-status-of-athletes-from-these-countries">refused to issue visas</a> to Russian and Belarussian fencers for a qualification competition in June. The International Fencing Federation moved the matches to Bulgaria where the neutral athletes could compete. </p>
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Read more:
<a href="https://theconversation.com/gender-inequality-will-still-be-an-issue-at-the-paris-2024-olympics-despite-the-games-being-gender-balanced-210883">Gender inequality will still be an issue at the Paris 2024 Olympics — despite the Games being gender-balanced</a>
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<p>As a more drastic step, French officials could simply ban all Russian and Belarussian athletes from travelling to Paris during the Olympics. The committee would likely have no recourse at this late date.</p>
<p>It would would align with the approach of some other EU member nations that <a href="https://www.france24.com/en/europe/20230523-russian-tourists-seek-new-destinations-as-europe-shuts-its-doors-over-ukraine-war">ban Russian tourism and travel</a>. </p>
<p>However, the French National Olympic Committee would likely oppose such a move. They might worry that it threatens the viability of their likely future <a href="https://olympics.com/ioc/news/the-french-alps-and-salt-lake-city-utah-invited-into-respective-targeted-dialogues-to-host-the-olympic-and-paralympic-winter-games-2030-and-2034">2030 Winter Olympic Games</a>.</p>
<p>At a time when so much international attention has turned to the Israel/Hamas war, will leaders, however frustrated, do anything in response?</p>
<p>Only time will tell, but one thing’s for sure: whatever happens will be carefully calculated to account for the vast array of geopolitical moving parts.</p><img src="https://counter.theconversation.com/content/219796/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Keith Rathbone 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>The International Olympic Committee has ruled politically-neutral individual athletes are eligible, but some nations aren’t happy about it.Keith Rathbone, Senior Lecturer, Modern European History and Sports History, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1078892018-12-10T18:55:39Z2018-12-10T18:55:39ZHow physical activity in Australian schools can help prevent depression in young people<figure><img src="https://images.theconversation.com/files/249145/original/file-20181206-186067-1j5ydwl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many young people don't recover from depression, and exercise can help prevent it from developing in the first place.</span> <span class="attribution"><span class="source">www.shutterstock.com</span></span></figcaption></figure><p>Adolescence is a critical time for the development of mental health problems. In fact, depression is most likely to occur during <a href="https://www.ncbi.nlm.nih.gov/pubmed/17551351">adolescence and young adulthood</a>. It’s the <a href="https://www.ncbi.nlm.nih.gov/pubmed/21652063">leading cause of disability</a> in young people worldwide. </p>
<p>At least one‐quarter of young people will experience an episode of depression <a href="https://www-ncbi-nlm-nih-gov.wallaby.vu.edu.au:4433/pubmed/9827321?dopt=Abstract">before 19 years of age</a>. By year 9, students who have experienced a mental disorder are on average two years behind in academic achievement compared to <a href="https://youngmindsmatter.telethonkids.org.au/siteassets/media-docs---young-minds-matter/childandadolescentmentalhealthandeducationaloutcomesdec2017.pdf">those without a mental disorder</a>.</p>
<p>The consequences of depression in adolescence are serious and can be lifelong. These include an <a href="https://www-ncbi-nlm-nih-gov.wallaby.vu.edu.au:4433/pubmed/11879160?dopt=Abstract">increased risk</a> of <a href="https://www-ncbi-nlm-nih-gov.wallaby.vu.edu.au:4433/pubmed/11879160?dopt=Abstract">depression late in life</a>, poor social functioning and academic achievement and reduced employment security, as well as greater risk of <a href="https://www-ncbi-nlm-nih-gov.wallaby.vu.edu.au:4433/pubmed/9735611?dopt=Abstract">suicide and self‐harm</a>. </p>
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Read more:
<a href="https://theconversation.com/what-can-parents-do-about-their-teenagers-mental-health-25066">What can parents do about their teenagers' mental health?</a>
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<p>Many young people don’t recover from depression, despite treatment with the best available <a href="https://www-ncbi-nlm-nih-gov.wallaby.vu.edu.au:4433/pubmed/17135991?dopt=Abstract">evidence‐based treatment approaches</a>. Given the scope and impact of depression in young people, and poor recovery rates, it’s crucial to understand how to help prevent the development of depression in young people.</p>
<p>An increasing body of evidence indicates physical activity and exercise are effective for <a href="https://www.ncbi.nlm.nih.gov/pubmed/28994355">improving mood</a>. We recently also examined studies to assess the efficacy of physical activity and exercise as a prevention for depression in young people. We found eight controlled research studies that examined this. These studies showed exercise and physical activity are effective as a <a href="https://www.ncbi.nlm.nih.gov/pubmed/30302925">depression-prevention approach</a> for young people. </p>
<h2>How much physical activity do young people need to do?</h2>
<p>Few young people seek professional help <a href="https://www.mja.com.au/journal/2007/187/7/when-and-how-do-young-people-seek-professional-help-mental-health-problems">for mental health concerns</a>. It’s important to engage young people in places that suit them to prevent the onset of mental health problems. Prevention and early intervention are crucial and especially relevant in the education setting. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249152/original/file-20181206-186064-181v9fy.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">Many young people never recover from depression once it is established.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
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</figure>
<p>The Australian guidelines state young people should engage in <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/health-pubhlth-strateg-phys-act-guidelines#apa1317">60 minutes of physical activity a day</a>. The majority of young people <a href="http://www.abs.gov.au/australianhealthsurvey">don’t reach this target</a>. </p>
<p>In fact, disengagement from regular exercise, physical activity and sporting clubs <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2821311/">steadily increases during adolescence</a>. This coincides with the average age of <a href="https://www.ncbi.nlm.nih.gov/pubmed/17551351">onset of depression</a>.</p>
<p>Physical activity is an important part of the <a href="https://www.australiancurriculum.edu.au/">Australian Curriculum</a>. The Australian <a href="https://www.legislation.gov.au/Details/C2011C00334">national policy</a> requires government schools to provide at least two hours of physical activity per week during <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1753-6405.12751">primary education and junior secondary education</a>. The provision of any physical education is not required as part of the <a href="https://www.australiancurriculum.edu.au/senior-secondary-curriculum/">senior secondary curriculum</a>. Even during primary education and junior secondary education, the mandated 120 minutes a week doesn’t meet Australian guidelines. </p>
<p>Schools are a key site for the <a href="http://apps.who.int/iris/bitstream/handle/10665/43923/9789241596862_eng.pdf?sequence=1&isAllowed=y">promotion of healthy behaviours</a>. Many long-term health-related behaviours and patterns – both positive and negative – are established during the developmental phase of <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60072-5/fulltext">adolescence and early adulthood</a>. </p>
<h2>How do we get them to do more?</h2>
<p>The research indicates physical activity is associated with <a href="https://www-ncbi-nlm-nih-gov.wallaby.vu.edu.au:4433/pubmed/29690792?dopt=Abstract">reduced risk of depression</a> in young people. Physical activity is an <a href="https://www.sciencedirect.com/science/article/abs/pii/S1755296609000027">acceptable</a>, non-stigmatising approach to promoting better mental health <a href="https://www.ncbi.nlm.nih.gov/pubmed/17620162">in young people</a>. To meet the <a href="https://www.ncbi.nlm.nih.gov/pubmed/21192795">specific needs of young people</a>, a physical activity program should facilitate self-reliance, motivation, and mental health and wellbeing literacy. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249154/original/file-20181206-186079-1fzh9r0.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">Depression is the leading cause of disability for young people across the globe.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/25956760">Motivation to engage in physical activity</a> can be increased by offering choice of activities, increasing skills and ability to engage in physical activity, and opportunities for social connection. Schools are best placed to ensure physical activity is increased and protected within the Australian curriculum and that young people meet the Australian guidelines for physical activity each day. </p>
<p>Most school-based intervention <a href="https://www.sciencedirect.com/science/article/pii/S0022347605001009">studies</a> of physical activity have used supervised programs of moderate to vigorous physical activity. These consist of 30 to 45 minutes, three to five days per week. The physical activity should include a variety of activities, be age-appropriate and enjoyable. </p>
<p>Some researchers suggest schools could also promote physical activity <a href="https://files.eric.ed.gov/fulltext/ED497155.pdf">outside physical education classes</a> by ensuring at least 20 minutes of recess per day. </p>
<p>Finally, physical educators <a href="https://www.sciencedirect.com/science/article/pii/S003306201400142X">can be key drivers</a> of physical and health literacy and behaviour change. They can do this, for example, through school-based activities and by providing information about the benefits of physical activity via newsletters and notices sent home.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/yes-your-kids-can-run-all-day-theyve-got-muscles-like-endurance-athletes-95428">Yes, your kids can run all day – they’ve got muscles like endurance athletes</a>
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<p>Physical activity programs within schools should also address the health, mental health and stress-reduction motivations for engaging in physical activity and focus on the benefits of participation. This should include <a href="http://www.euro.who.int/__data/assets/pdf_file/0005/175325/e96697.pdf">a focus on fun and enjoyment</a>, while building confidence and independence.</p>
<p>Any physical activity program delivered in schools should also encourage young people to draw on <a href="https://www.tandfonline.com/doi/abs/10.1080/1750984X.2010.548528">parental and social support</a> to increase the physical activity they do outside school time.</p><img src="https://counter.theconversation.com/content/107889/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexandra Parker receives funding from NHMRC. </span></em></p><p class="fine-print"><em><span>Michaela Pascoe 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>Research indicates exercise is effective for improving mood and preventing the development of depression in young people.Alexandra Parker, Professor of Physical Activity and Mental Health, Victoria UniversityMichaela Pascoe, Postdoctoral Research Fellow in Exercise and Mental Health, Victoria UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/923662018-02-26T11:57:04Z2018-02-26T11:57:04ZCan coffee improve your workout? The science of caffeine and exercise<figure><img src="https://images.theconversation.com/files/207827/original/file-20180226-120971-1b6j9ij.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/image-photo/resting-runner-260897984?src=XTj1Xdt-nA15eRNsMggkmg-1-1">Shutterstock</a></span></figcaption></figure><p>Caffeine is one of the most researched substances reported to help athletes perform better and train longer and harder. As a result, professional and amateur sportspeople often take it as a performance-enhancing “ergogenic” aids for a wide range of activities. These include intermittent exercise such as football and racket sports, endurance exercise such as running and cycling, and resistance exercise such as weightlifting.</p>
<p>But while most research looks at the effects of pure caffeine consumed as tablets with water, in the real world most people get their caffeine from coffee, energy drinks or other products like special gels or <a href="https://link.springer.com/article/10.1007/s40279-017-0848-2">chewing gum</a>. So will drinking a cup of joe before your workout actually make a difference? The answer could depend as much on your genes as what kind of coffee you’re drinking.</p>
<p><a href="https://jissn.biomedcentral.com/articles/10.1186/1550-2783-7-5">Scientists think</a> caffeine affects the body chemical adenosine, which normally promotes sleep and suppresses arousal. Caffeine ties up the receptors in the brain that detect adenosine and so makes it more alert.</p>
<p>But it may also increase stimulation of the central nervous system, making exercise seem like it involves less effort and pain. In high-intensity activities such as resistance training or sprinting, it may increase the number of fibres used in muscle contractions, meaning movements can be more frequent and forceful. </p>
<h2>Faster, higher, stronger</h2>
<p>Research has shown that pure caffeine can help endurance athletes <a href="https://link.springer.com/article/10.1007/s40279-014-0257-8">run faster</a> and <a href="http://www.mdpi.com/2072-6643/7/7/5219/htm">cycle for longer</a>. It can help footballers to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279366/">sprint more often and over greater distances</a>, and basketball players to <a href="http://www.mdpi.com/2072-6643/9/9/1033/htm">jump higher</a>. It can help <a href="http://online.liebertpub.com/doi/abs/10.1089/jcr.2012.0019?journalCode=jcr">tennis players</a> and <a href="https://journals.lww.com/acsm-msse/fulltext/2016/01000/Effect_of_Caffeine_on_Golf_Performance_and_Fatigue.18.aspx">golfers</a> to hit the ball with greater accuracy. And it can help <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2876999/pdf/1550-2783-7-18.pdf">weightlifters lift more weight</a>.</p>
<p>The evidence for caffeine’s effects on sprinting is more mixed. Limited improvements <a href="http://www.mdpi.com/2075-4663/4/3/45">have been found</a> for events lasting under three minutes. But for races of around ten seconds,
caffeine can improve peak <a href="https://jissn.biomedcentral.com/articles/10.1186/1550-2783-12-S1-P57">power output, speed, and strength</a>.</p>
<p>An increasing number of studies have also shown that coffee can be used as an alternative to caffeine to <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059561">improve cycling</a> and <a href="https://journals.humankinetics.com/doi/abs/10.1123/ijspp.2017-0456?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed&">competitive running</a> performance, and produce similar results similar to pure caffeine. In fact, coffee may even be more effective at <a href="https://journals.lww.com/nsca-jscr/Abstract/2016/10000/Effect_of_Coffee_and_Caffeine_Ingestion_on.27.aspx">improving resistance exercise than caffeine alone</a>. Similarly, drinking <a href="https://jissn.biomedcentral.com/articles/10.1186/1550-2783-10-1">energy drinks</a> containing caffeine before exercise can improve mental focus, alertness, anaerobic performance and endurance performance.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=330&fit=crop&dpr=1 600w, https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=330&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=330&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=414&fit=crop&dpr=1 754w, https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=414&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/207825/original/file-20180226-120971-lly7xa.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=414&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">Total weight lifted when performing back squats to failure.</span>
<span class="attribution"><a class="source" href="https://journals.lww.com/nsca-jscr/Abstract/2016/10000/Effect_of_Coffee_and_Caffeine_Ingestion_on.27.aspx">Journal of Strength and Conditioning Research</a>, <span class="license">Author provided</span></span>
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<p>But drinking coffee isn’t like taking a measured dose of caffeine. The amount of stimulant in a cup, and so how it affects you, will depend on the blend of coffee and how it is brewed. Studies have shown consuming either <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059561">0.15g</a> or <a href="https://journals.humankinetics.com/doi/abs/10.1123/ijspp.2017-0456?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed">0.09g</a> of caffeinated coffee per kilogram of body weight can improve performance. So a dessert spoon of coffee granules rather than a traditional teaspoon is probably best. </p>
<p>It’s also worth bearing in mind that each piece of research shows caffeine improves athletic performance of a group of people as a whole. But we also know that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752738/pdf/40279_2017_Article_776.pdf">genetic factors</a> have a big influence on our responses to caffeine and not everyone reacts in the same way. This means consuming caffeine won’t necessarily improve your performance.</p>
<h2>Potential downsides</h2>
<p>In fact, you could end up feeling nauseated and jittery at a time when, if you are competing, you are already feeling anxious. And, as caffeine’s effects can linger for up to <a href="https://www.ncbi.nlm.nih.gov/books/NBK223808/">five hours</a>, taking it too late in the day could disrupt your sleep, which is a big factor in health and fitness in general. This means it’s important to practice with caffeine during training sessions or friendly fixtures before using it for an important event. </p>
<p>Some <a href="http://www.mysportscience.com/single-post/2017/06/18/Do-you-need-to-refrain-from-coffee-to-get-the-maximal-effect-of-caffeine">have also suggested</a> that you should abstain from caffeine in order to enjoy a better effect on your performance when you consume it for exercise. But maintaining your normal intake will prevent any <a href="https://theconversation.com/caffeine-withdrawal-drives-need-for-more-but-are-we-addicts-17380">possible withdrawal symptoms</a> and still provide benefits if caffeine is taken before exercise. Its effects peak between <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4898153/pdf/ictx-54-308.pdf">30 and 75 minutes after ingestion</a>.</p>
<p>Finally, it’s a a commonly held belief that caffeine is a diuretic that will lead to dehydration because it makes you produce more urine. But a <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0084154">number of studies</a> have shown that this isn’t the case with moderate amounts of coffee, cola or any other caffeinated beverage, which help keep you hydrated like any other drink.</p><img src="https://counter.theconversation.com/content/92366/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Neil Clarke receives funding from The Institute for Scientific Information on Coffee. </span></em></p>Drinking coffee before exercising could make you run faster and lift heavier - if you’ve the right genes.Neil Clarke, Principal Lecturer in Sport and Exercise Science at Coventry University, Coventry UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/781862017-06-06T19:21:56Z2017-06-06T19:21:56ZOur ‘sporting nation’ is a myth, so how do we get youngsters back on the field?<figure><img src="https://images.theconversation.com/files/171965/original/file-20170602-25700-1e6r1fb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Neglected and sub-par facilities are one of many barriers to youth participation in sport.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/tupwanders/4090730864/">tup wanders</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Sport is seen as a key part of Australia’s identity. Yet woefully rundown facilities and outdated sport offerings are creating significant barriers to youth participation. </p>
<p>In partnership with the <a href="http://yourlocalclub.com.au/who-we-are/our-stories/">Cooks River Sporting Alliance</a>, Canterbury Hurlstone Park RSL Club, and 12 public and private schools from Sydney’s inner west, we’ll be working with youth to co-design an innovative program to reverse the decline in youth participation in sport. </p>
<p>Our program, Designing in Youth, will feature new sport offerings, advertising materials and redesigned facilities. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3315587/">Research</a> shows that environmental design works best when it considers multiple factors. Thus, the first phase of our project is a survey to identify psychological and social barriers alongside environmental drivers of youth sport participation. </p>
<h2>Barriers to participation</h2>
<p>Australia’s sporting landscape offers more barriers than motivations for youth, and the effects are obvious. The World Health Organisation recommends 60 minutes of physical activity every day. In Australia, only <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/health-pubhlth-strateg-active-evidence.htm">one in ten</a> young adults do this. </p>
<p>Despite many programs to increase youth physical activity and sport participation, <a href="https://www.ncbi.nlm.nih.gov/pubmed/18091006">results have been inconsistent</a>. Perhaps these programs’ failure to have a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3871410/">lasting impact</a> on young people’s exercise habits is due to their <a href="http://pediatrics.aappublications.org/content/107/6/1459">highly structured</a> nature and <a href="http://docslide.net/documents/in-focuspositive-coaching-youth-sports-hold-a-lesson-for-leaders.html">lack of youth leadership</a>.</p>
<p><a href="http://docslide.net/documents/in-focuspositive-coaching-youth-sports-hold-a-lesson-for-leaders.html">Youth report</a> their reasons for playing sport include enjoyment, development of physical and motor skills, self-esteem and peer interaction, among other factors. We hypothesise that better interventions emphasise the fun factor and involve peer-led, unstructured play. This should produce long-lasting improvements in attitudes to physical activity. </p>
<p>Most organised sports promote practice and winning over play, are primarily coach-led and do not encourage the development of physical and motor skills. These <a href="http://journals.sagepub.com/doi/abs/10.1177/1356336X14555294">factors are barriers</a> to youth sport participation. </p>
<p>This is partly due to poorly designed facilities. Few facilities promote both social and competitive participation, focus on peer leadership, or offer a wide variety of sporting activities in one place. </p>
<h2>Neglect of grassroots sport</h2>
<p>In New South Wales, the divide between elite and grassroots sport is huge. Most youth participation is in grassroots sport, but the funding <a href="http://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/pubs/BN/2012-2013/SportFunding#_Toc360096410">mostly goes into elite clubs</a>. </p>
<p>Sports fields for grassroots clubs are commonly placed as afterthoughts, typically on leftover land. In NSW, this can be seen along Cooks River in the suburbs of Hurlstone Park and Canterbury. Here, sporting events and practices are regularly cancelled due to flooding.</p>
<p>To make things worse, many fields are not designed for sport and poorly maintained. The uneven, pitted surfaces are bad for play.</p>
<p>At these fields, bathroom blocks are rare, dirty and often falling apart. There are usually no changing rooms or showers. Many fields have few, if any, benches to sit on, and no access to food and drink vendors. </p>
<p>In addition, facilities are usually designed for one sport only. This leaves parents or siblings with nothing else to do while they wait.</p>
<p>In other countries, such as the Netherlands, facilities for local sport clubs <a href="http://www.cladglobal.com/CLADnews/architecture-design/Feyenoord-football-stadium-design-architecture-OMA-David-Gianotten-Eredivise-Netherlands-regeneration/326277?source=news">function as community centres</a>. Their fields are designed for various sporting activities and have playgrounds and hospitality centres nearby. </p>
<h2>Why does participation matter?</h2>
<p>The decline in sport participation may be a factor in the rise of poor mental health. Despite decreases in substance abuse such as smoking and binge drinking, rates of self-harm, depression, anxiety and suicide are <a href="http://www.health.gov.au/internet/ministers/publishing.nsf/Content/health-mediarel-yr2015-ley096.htm">on the rise</a> among Australian youth. </p>
<p><a href="http://www.who.int/dietphysicalactivity/factsheet_young_people/en/">Many studies</a> have found habitual sport activities are an effective way to improve mental health. Other health benefits include reductions in obesity and blood pressure. The 2010 report, <a href="https://www.health.gov.au/internet/main/publishing.nsf/Content/aust_sport_path/%24file/aust_sport_path.pdf">Australian Sport: Pathway to Success</a>, recognised boosting youth participation in sport and supporting grassroots clubs as important for improving both population health and national sporting success. </p>
<p>Despite all this evidence of many benefits, studies have charted a <a href="http://www.who.int/whr/2002/en/">steady global decline in sport participation</a> between the ages of 11 and 16. Participation is particularly low among <a href="http://www.emeraldinsight.com/doi/pdfplus/10.1108/09654280010343555">older girls</a>. </p>
<p>Past studies have <a href="http://www.who.int/whr/2002/en/">identified some barriers</a> to participation. These include <a href="http://www.emeraldinsight.com/doi/pdfplus/10.1108/09654280010343555">reduced parental influence</a> on choice of activity, boredom with the available sports, and <a href="http://www.sportandrecreationspatial.com.au/resources/2014%20JSAMS%20Transition3..pdf">time challenges</a> created by increased academic workload.</p>
<p>Other possible barriers such as poorly designed and maintained public parks have not been well studied. It’s probable that the poor condition of facilities and the lack of variety in sports and other non-sporting amenities on offer also discourage participation.</p>
<h2>A new approach to involving youth</h2>
<p>If we’re to increase youth participation, we need to include their opinions in the redesign process to ensure being involved in sport appeals to them.</p>
<p>Most programs worldwide have focused only on promoting an overall increase in physical activity. But regular and vigorous sports participation has greater long-term benefits, including improvements in <a href="https://www.dsr.wa.gov.au/docs/default-source/file-support-and-advice/file-research-and-policies/brain-boost-how-sport-and-physical-activity-enhance-children%27s-learning.pdf?sfvrsn=4">children’s learning</a>. </p>
<p>We hope Designing in Youth will help create a whole new landscape for sport in Sydney’s inner west. If successful, our communities and our use of public outdoor space will change for the better. </p>
<p>We should see youth outside again. And maybe, just maybe, we will restore our status as a sporting nation.</p><img src="https://counter.theconversation.com/content/78186/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deborah Ascher Barnstone receives funding from Canterbury Hurlstone Park RSL. </span></em></p><p class="fine-print"><em><span>Fiona Brooks receives funding from Hurlstone Park and Canterbury RSL
</span></em></p><p class="fine-print"><em><span>Job Fransen receives funding from Hurlstone Park/Canterbury RSL</span></em></p>The first step in reviving a lost sporting culture is to involve young Australians in working out why sport has lost its appeal and how to reverse the decline in youth participation.Deborah Ascher Barnstone, Professor, Associate Head of School, School of Architecture, University of Technology SydneyFiona Brooks, Professor of Public Health, Associate Dean Research, University of Technology SydneyJob Fransen, Lecturer in Skill Acquisition and Motor Control, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/753062017-05-05T01:53:37Z2017-05-05T01:53:37ZBeware the hype – springy soles won’t make you run much faster<figure><img src="https://images.theconversation.com/files/166241/original/file-20170421-12645-18gej98.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Springy soles, stiffer shoes, lightweight materials. When does shoe design give some runners an unfair advantage?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/544254466?src=ouwhewYFWf9JXeqj-kg3ig-1-45&size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>Most runners believe a good pair of running shoes is worth the investment. But advances in running shoe technology have <a href="https://www.nytimes.com/2017/03/08/sports/nikes-vivid-shoes-and-the-gray-area-of-performance-enhancement.html?_r=0">sparked debate</a> about whether shoes help you run faster.</p>
<p>Can they really allow marathon runners to break the <a href="https://link.springer.com/article/10.1007%2Fs40279-017-0708-0">elusive two-hour barrier</a>, a challenge set to take place in Italy <a href="http://www.runnersworld.com/2-hour-marathon/how-to-watch-saturdays-sub-2-marathon-attempt">this weekend</a>? Or can newer shoes help you improve your personal best? </p>
<p>If they do, can we class these shoes as “performance enhancing” technologies that give runners an unfair advantage?</p>
<h2>Light shoes, better performance</h2>
<p>The weight of your running shoes can have a <a href="https://dx.doi.org/10.1007/s40279-014-0283-6">significant impact</a> on running performance. As shoes get heavier, muscles use more energy to move your feet, causing you to fatigue earlier, reducing your running performance.</p>
<p>Advances in materials technology have allowed running shoes to get lighter and lighter. Premium running shoes weigh on average 250 to 340 grams each, while the controversial <a href="http://news.nike.com/news/nike-zoom-vaporfly-elite">Nike Zoom Vaporfly Elite</a> tips the scales at just 184 grams.</p>
<p>If shoe weight is so important, why not <a href="https://theconversation.com/mondays-medical-myth-run-barefoot-to-prevent-injuries-7901">run barefoot</a>? Running barefoot requires energy to be absorbed by the muscles of the legs and feet when the foot hits the ground. Shoe cushioning can alleviate some of that. However, adding cushioning also increases shoe weight. So, there is a trade-off between the benefit of cushioning and the detrimental effects of added weight.</p>
<p>A <a href="http://journals.lww.com/acsm-msse/pages/articleviewer.aspx?year=2014&issue=02000&article=00015&type=abstract">recent study</a> found running in shoes each weighing 211 grams resulted in the same energy consumed for a given running distance (called <a href="https://en.wikipedia.org/wiki/Running_economy">running economy</a>) as running barefoot. And running barefoot on a treadmill, that provides the same cushioning as shoes (without adding weight to the feet), produced a small (~1.6%) improvement in running economy. </p>
<p>So the ideal would be to provide enough cushioning with as little weight as possible for the best running performance.</p>
<h2>Springy shoes, the jury’s out</h2>
<p>Reducing muscular effort at impact through shoe cushioning can be beneficial. But traditional running shoes lose energy with every step (converted mainly to heat). So, this energy must be replaced, through muscular contraction, to propel the runner into the next step and prevent a drop in speed.</p>
<p>In fact, cushioned shoes <a href="http://rsif.royalsocietypublishing.org/content/13/119/20160174">increase activation</a> of foot and leg muscles during push-off, compared to barefoot running. So the benefit of cushioning during impact may be offset by the increase in muscular effort needed to push off.</p>
<p>What if we could get back the energy lost at impact? Recent developments in running shoe design have focused on developing lightweight cushioning materials that act like springs to store energy from foot impact and return it to help power push off. In theory, this could reduce the muscular effort required to both absorb impact and power push-off and potentially <a href="http://jap.physiology.org/content/92/2/469">improve running economy</a>. </p>
<p>But there are complications we must consider before “springing” to a conclusion.</p>
<p>Springs only return energy they absorb when the shoe hits the ground. Springs cannot generate the <em>extra</em> energy needed to run uphill or accelerate. So muscles must still do this extra work and we do not yet know how a spring influences their ability to do this. This may potentially affect how efficiently you run uphill, downhill, accelerate or slow down.</p>
<h2>Stiff shoes help, but not too stiff</h2>
<p>The way the foot moves is also important. Our toe joints naturally bend when we push off, which dissipates some of the energy added by calf muscle contraction.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165190/original/image-20170413-25898-145hwo3.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">
<figcaption>
<span class="caption">High speed x-ray of running foot during push-off, when the toes bend and absorb energy. A hypothetical carbon insole is shown, which should theoretically reduce how much the toes bend and therefore reduce energy lost.</span>
<span class="attribution"><span class="source">Author provided, with Mike Rainbow, Susan De'Andrea and Nicolai Konow.</span></span>
</figcaption>
</figure>
<p>Reducing the amount the toes bend by making shoes stiffer can reduce the amount of energy lost. Stiffer soled shoes <a href="http://journals.lww.com/acsm-msse/pages/articleviewer.aspx?year=2006&issue=03000&article=00023&type=abstract">can improve running economy</a>, but only if the bending stiffness is <a href="http://www.jbiomech.com/article/S0021-9290(17)30015-5/abstract">optimised</a> for the specific athlete.</p>
<p>Too stiff and the calf muscles have to work too hard to produce the required forces to rotate the ankle; too soft and the benefit becomes trivial. </p>
<p>So it is not surprising shoes <a href="http://www.runningshoesguru.com/2017/03/nike-zoom-vaporfly-elite-the-shoe-of-breaking2-you-cant-buy/">Nike is preparing</a> for running marathons in under two hours have carbon fibre insoles where the bending stiffness is “tuned” for each runner.</p>
<p>The optimal stiffness of a shoe sole also varies depending on factors like the runner’s weight, leg length and strength. But a bigger design problem is that the optimal bending stiffness also varies with constantly changing factors.</p>
<p>Running at different speeds means we must change how we activate our muscles. But a simple spring, such as the <a href="https://www.scientificamerican.com/article/blade-runners-do-high-tech-prostheses-give-runners-an-unfair-advantage/">carbon fibre blade</a>, cannot change its stiffness for different speeds. </p>
<p>Even if we could tune shoe stiffness as we ran, this wouldn’t help with the added effort required to run uphill or accelerate.</p>
<h2>Are shoes ‘performance enhancing’ devices?</h2>
<p>Advances in shoe technology have the potential to improve running economy. At most, it is estimated this might make a difference of <a href="https://link.springer.com/article/10.1007%2Fs40279-017-0708-0">up to 2% in running economy</a> when running on a flat course, in ideal conditions.</p>
<p>For professional runners, we don’t think the latest improvements in design provides an “unfair” advantage because the shoes do not give runners extra energy; they only help preserve energy our muscles generate and are likely to require precise conditions to be effective.</p>
<p>While recreational runners may get a small performance benefit from lighter, better cushioned or slightly springy shoes, they would be better off increasing their fitness, and making sure their next shoes are comfortable and fit to reduce the chance of injury.</p><img src="https://counter.theconversation.com/content/75306/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Glen Lichtwark has received research funding from Asics Oceania to conduct footwear and running related research. He receives funding from the Australian Research Council (ARC), Cerebral Palsy Alliance and Cerebral Palsy International Research Foundation. He currently holds an ARC Linkage project in collaboration with the Australian Sports Commission. He is a council member with the International Society of Biomechanics</span></em></p><p class="fine-print"><em><span>Dominic Farris receives funding from the Australian Research Council (ARC) including a current ARC Linkage Project in collaboration with the Australian Sports Commission. He has also applied for ARC funding in collaboration with Asics Oceania to research foot and footwear biomechanics. He is a member of the International Society of Biomechanics. </span></em></p><p class="fine-print"><em><span>Luke A Kelly has received funding from Asics Oceania to conduct footwear and running related research. He receives funding from the Australian Research Council (ARC) and the National Health & Medical Research Council of Australia. He is a member of the scientific committee for Sports Medicine Australia.</span></em></p>Running shoes with springs in the soles have been touted as the next big thing in shoe design. But they won’t turn a weekend warrior into an Olympian.Glen Lichtwark, A/Prof in Exercise and Sport Science, The University of QueenslandDominic Farris, Research fellow, The University of QueenslandLuke A Kelly, Research Fellow, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/652982016-09-15T07:41:03Z2016-09-15T07:41:03ZYour body makeover training programme could be a waste of time<figure><img src="https://images.theconversation.com/files/137729/original/image-20160914-4972-1jqinzw.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>Thanks to social media, it’s hard to escape from hearing about people’s fitness levels. Sites like Facebook and Instagram provide a constant stream of information about user’s gym visits, nutrition plans and race results. Selfies chronicle every inch of fat loss and muscle gain and promote “miraculous” training plans that claim to be able shape your body with little effort.</p>
<p>Unfortunately, most of these claims are not scientifically based and may lead to results that <a href="http://uk.businessinsider.com/kayla-itsines-review-2016-6?r=US&IR=T">don’t match your expectations</a>. Your response to fitness training doesn’t just depend on what regime you follow but how well your genes respond to it, as well as other factors related to your lifestyle and environment. In fact, you could follow a makeover training plan and find it makes no difference to your fitness whatsoever. </p>
<p>In the last 20 years, research has developed an incredible number of tests that can predict how well we would perform in a competition. Some of the most well known are <a href="https://www.mcmillanrunning.com/">race-time predictors</a> and calculators for <a href="https://www.brianmac.co.uk/maxload.htm">the maximum load</a> you can manage for weight-training exercises. These prediction tools all assume that if you do the training you’ll get the results and that you don’t have limits.</p>
<p>But research increasingly suggests that there are huge differences between people when it comes to how our bodies respond to exercise. This was first demonstrated in 1995 by the landmark <a href="http://www.pbrc.edu/heritage/index.html">Heritage Family Study</a>, a project designed to evaluate the role of genetic and non-genetic factors in cardiovascular, metabolic and hormonal responses to aerobic exercise. </p>
<p>In <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938186/">one of the studies</a>, 742 completely sedentary people were put on an identical, progressively challenging 20-week training programme, and their physiological responses measured. Participants were also adjusted for age, sex, body mass and body composition in order to study different groups equally. </p>
<p>Following the training, aerobic performance improved by an average of 19%. But while some participants improved by as much as 40%, others didn’t improve at all. Researchers labelled these unfortunate people “non-responders”. It’s frustrating, to say the least, to think that all those hard training sessions could amount to nothing. </p>
<p>There was a large variation in response to training for all ages, ethnicities, genders and levels of initial fitness. Thanks to a comparison between groups it was possible to determine that genetic factors explained about 40% of the variation in aerobic fitness after the 20-week training program. This information provides us with an idea of how important genetic factors are on performance outcomes.</p>
<p>The study didn’t prove exactly what other factors explained the varied results, although other research has suggested that <a href="http://www.ncbi.nlm.nih.gov/pubmed/19826310">differences in body measurements</a>, <a href="http://www.sciencedirect.com/science/article/pii/S0005789404800169">commitment</a> and personal willpower can play a big role. But none of the non-genetic variables measured before training appeared to influence the difference between responders and non-responders.</p>
<p>This suggests the variety of responses to the training programme is an example of the normal biological diversity of humans. The differences in people’s ability to adapt to regular exercise went well beyond measurement error and day-to-day fluctuations and so can tell us a lot about the physiological and metabolic mechanisms involved.</p>
<p>In addition, there was about 2.5 times more variance between families than within families for the gains in aerobic fitness. But there was no relationship between initial level of aerobic fitness and how much it changed after the training. So it appears that one set of genes influenced the initial level and another set of genes influenced the response to training. As a result, part of the genetic component for aerobic fitness only comes into play in response to an active lifestyle.</p>
<h2>Finding the right genes</h2>
<p>Other studies have tried to identify which genes and mutations are associated with fitness levels when you’re sedentary and how you respond to training. For example, a variant in the muscle form of the creatine kinase gene (CKM) has been linked to the capability of being trained for aerobic fitness. <a href="http://www.ncbi.nlm.nih.gov/pubmed/12968206/">Similar projects</a> are trying to find genes related to blood pressure, your response to glucose and insulin, how much abdominal visceral fat you produce and how much blood your heart pumps. This might help us better understand the differences between responders and non-responders.</p>
<p>Scientists have even created a multi-gene DNA test they claim could show you <a href="http://www.xrgenomics.com/">how good a responder you are</a>. This test scores a set of DNA sequences for the occurrence of specific nucleotides, the building blocks of DNA. The combination of these scores is used to determine how likely you are to make gains in aerobic capacity following an exercise training programme. In simple terms, it can tell you whether you are a high responder or not. This could help you focus on realistic goals and change your <a href="https://www.dnafit.com/downloads/DNAFit%20Clinical%20Study.pdf">training schedule</a> accordingly. </p>
<p>But exercise isn’t just about becoming a fitness champion or transforming yourself into a social media star. In the vast majority of cases, exercise will be incredibly beneficial for your <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1402378/">general health</a>. Research shows that physical activity can also <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603361/">boost self-esteem</a>, mood, <a href="http://well.blogs.nytimes.com/2013/08/21/how-exercise-can-help-us-sleep-better/?_r=0">sleep quality</a> <a href="https://www.sciencedaily.com/releases/2006/11/061101151005.htm">and energy</a>, as well as reducing your risk of <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC474733/">stress and depression</a>. If you have the genetic potential to become an athlete or model you will realise it, but otherwise you should just remember to enjoy yourself.</p><img src="https://counter.theconversation.com/content/65298/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alberto Dolci 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>Why that fitness plan you saw online probably won’t help you lose as much weight as it claims.Alberto Dolci, Lecturer in Exercise and Environmental Physiology and Exercise Immunology, University of WestminsterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/598192016-05-24T03:00:02Z2016-05-24T03:00:02ZWalking challenges aren’t doing you much good if you’re swapping running for walking<figure><img src="https://images.theconversation.com/files/123535/original/image-20160523-9565-1buo9wp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Walking challenges attract people who are already active.</span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>Walking or pedometer challenges such as the yearly <a href="https://www.gettheworldmoving.com/">Global Corporate Challenge</a> starting tomorrow are a popular way to get large numbers of people moving. While walking has many health benefits, evidence has found the program doesn’t target people who need it, and people swap high-intensity exercise for more steps.</p>
<p>Participants in the Global Corporate Challenge are organised into work teams that compete against other teams to accrue the most steps. During the 16-week challenge, participants receive weekly encouraging emails to keep up their interest. However, because of the costs involved, many workplaces set up their own walking challenges, which is easy enough as you only need pedometers (or other activity-tracking devices) and a spreadsheet to record the daily steps taken.</p>
<h2>Reaching the right people?</h2>
<p>There are indications these walking challenges, while a good idea, are not getting inactive people to become active. A <a href="http://www.publish.csiro.au/view/journals/dsp_journal_fulltext.cfm?nid=292&f=HE14033">recent study</a> found 92% of participants were already sufficiently active, according to <a href="http://apps.who.int/iris/bitstream/10665/44399/1/9789241599979_eng.pdf">physical activity guidelines</a>, before the challenge began. </p>
<p>The guidelines state that <a href="http://scholarcommons.sc.edu/sph_physical_activity_public_health_facpub/119/?utm_source=scholarcommons.sc.edu/sph_physical_activity_public_health_facpub/119&utm_medium=PDF&utm_campaign=PDFCoverPages">for good health</a> we should engage in least 150 minutes of moderate physical activity (such as brisk walking) or 75 minutes of vigorous physical activity (such as playing basketball or running), in addition to muscle-strengthening activities on at least two days each week.</p>
<h2>Swapping the run for a walk</h2>
<p>There is also anecdotal evidence the intensity of movement is reduced in favour of accumulating more steps. Participants told us they swapped a faster but shorter run or gym session for a longer walk to collect more steps. However, there are <a href="http://www.sciencedirect.com/science/article/pii/S0002914905016991">benefits to moving</a> at a higher intensity, when the heartbeat increases and we start to huff and puff, especially for heart health.</p>
<p>In one soon-to-be-published study an organisation created its own walking challenge. We measured stair use at the same time, guessing the participants would also use the stairs more. We measured stair use with infra-red monitors before the walking challenge and then again during the challenge. </p>
<p>We were pleased to see an increase in stair use, until we looked at the direction in which the participants had taken the stairs. They were walking down the stairs more but climbing the stairs less than before the walking challenge.</p>
<p>This is a problem because climbing stairs is considered vigorous physical activity, similar in intensity to jogging or playing football. These activities are around <a href="https://sites.google.com/site/compendiumofphysicalactivities/home">eight times</a> the body’s metabolic rate, or the amount of energy the body uses when resting or sleeping, or five to six times more than when sitting. Walking down the stairs, on the other hand, is not much different to walking on a flat surface and expends only twice the energy of when you’re sitting.</p>
<h2>So how do you make the most of your walking challenge?</h2>
<p>This doesn’t mean you shouldn’t take part in walking challenges. Walking is a great way to exercise since there is no need for special equipment, clothes or location, it can be done for transport, you often don’t need to take a shower afterwards, it suits most people of all ages, and it can be very social.</p>
<p>Just make sure you’re not cutting out more vigorous exercise in favour of walking. Increase the intensity by walking a little faster than normal. Make a game out of overtaking other pedestrians. Try timing how long it takes to climb the stairs at work, or walk a particulate route and see if you can shave off a few seconds or minutes each week.</p>
<p>Find hillier routes to walk, or find as many stairs to climb as you can along your way. Walk up the escalator, or take the stairs up. Find a person in the crowd and try to get to the top of the stairs before they do. Mix it up by walking backwards to use other sets of muscles.</p>
<p>Many short distances add up. Walk around the workplace, grab a glass of water, or go for a lunchtime walk. This also has the benefit of <a href="http://theconversation.com/health-check-the-low-down-on-standing-desks-37515">breaking up prolonged sitting</a>.</p>
<p>If you are not used to walking a lot, ease into it. Starting with shorter distances and build up as you go. Wear comfortable footwear and do make sure you listen to your body: if something hurts, take it easy. It can also be good to warm up your muscles and joints before walking fast and to stretch a little afterwards.</p><img src="https://counter.theconversation.com/content/59819/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lina Engelen receives funding from the Heart Foundation. She is also director of Chaenge, a workplace health evaluation consultancy within the University of Sydney. Lina also co-chairs the Healthier Workplaces Project Node at The Charles Perkins Centre, University of Sydney.</span></em></p><p class="fine-print"><em><span>Josephine Chau consults for Chaenge, a workplace health evaluation consultancy within the University of Sydney. She receives funding from Heart Foundation NSW Division for research about promoting physical activity and reducing sitting at work, and from Healthy Sydney University for sit-stand desk research. Josephine is supported by a Postdoctoral Fellowship (no. 100567) from the National Heart Foundation of Australia. She co-chairs the Healthier Workplaces Project Node at The Charles Perkins Centre, University of Sydney.</span></em></p>While walking is a great way to get people moving, evidence has found the program doesn’t target people who need it the most, and people swap high intensity exercise for more steps.Lina Engelen, Research Fellow in Physical activity and workplace health, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/556382016-03-08T19:04:39Z2016-03-08T19:04:39Z‘Girls Make Your Move’ exercise ads look good but are unlikely to deliver on their own<figure><img src="https://images.theconversation.com/files/114197/original/image-20160308-15315-ph99q0.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The ads are aimed at engaging the girls who enjoy being active but have fallen out of the habit .</span> <span class="attribution"><a class="source" href="http://www.health.gov.au/internet/girlsmove/publishing.nsf/Content/home">Screenshot of the Girls Make Your Move website. </a></span></figcaption></figure><p>We all know that being active has <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/phy-activity">physical, social and emotional benefits</a>. In primary school, the average kid does more than 100 minutes of moderate-to-vigorous physical activity each day. But it’s all downhill from there, especially for girls. By the time they are 15-17-years-old, girls are active for <a href="http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/462FBA87B642FCA4CA257BAC0015F3CE?opendocument">less than 30 minutes</a> each day.</p>
<p>Teenagers should be doing <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/guide-es">at least 60 minutes</a> of moderate- to vigorous-intensity physical activity every day. In 2010, only 5.9% of girls (compared to 18.7% of boys) in year 11 were <a href="http://www.cancer.org.au/content/pdf/CancerControlPolicy/Publications/MediaMaterials/Physical_activity_research_memo_NaSSDA_updated.pdf">meeting the physical activity guidelines</a>.</p>
<p>Last week the Australian government launched the <a href="http://www.health.gov.au/internet/girlsmove/publishing.nsf/Content/home">Girls Make Your Move</a> campaign. The campaign aims to encourage young women aged 12 to 19 to be more active. </p>
<p>According to the accompanying <a href="http://health.gov.au/internet/girlsmove/publishing.nsf/Content/940079ADC8FEB9D5CA257F660021CACD/$File/Insights%20Report.pdf">Insights Report</a>, the campaign targets two groups of young women. First, those who enjoy physical activity and team sports but participate less often than they would like. Second, those who are disinterested in physical activity and don’t see any reason to be involved.</p>
<p>The <a href="http://www.health.gov.au/internet/girlsmove/publishing.nsf/Content/tvc-45sec">TV ads</a> show young women engaged in a range of sports and activities, with motivating music and catchy hashtags. There are also a series of print ads and billboard ads, each featuring a different sport or activity.</p>
<p>The reaction to these ads has been largely positive, with <a href="http://www.mamamia.com.au/girls-make-your-move/">praise for its positive tone</a> and the inclusion of girls of different cultures, body shapes and abilities. It is great to see the government has taken on board the finding from the campaign research that girls want to see positive messages about having fun rather than hearing about the health risks of being inactive. </p>
<p>This is also consistent with evidence that traditional approaches of scaring people into changing their health behaviours <a href="https://www.prevention.org/resources/sapp/documents/ineffectivenessoffearappealsinyouthatodprevention-final.pdf">generally don’t work</a> with young people. Another tick is that it’s not just an ad campaign; there are plenty of local events for girls to engage with on the ground.</p>
<p>Negative reactions have generally focused on the (acknowledged) <a href="http://www.campaignbrief.com/2016/02/girls-make-your-move-the-messa.html">copying of a UK campaign</a> and the use of an American soundtrack. </p>
<p>There have also been some “what the…” responses to the use of “Sweat Now. Be Sweet Later” as a catch-cry. I suspect this was meant to address inactive girls’ concerns about being sweaty and uncomfortable, but its reception on Twitter suggests it may have fallen short:</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=223&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=223&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=223&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=280&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=280&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114191/original/image-20160308-15341-fwk9op.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=280&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>
</figcaption>
</figure>
<h2>You’re mobilised to move, then what?</h2>
<p>The Insights Report emphasised the need for the use of multiple media channels, and particularly social media. So, what did we get?</p>
<p>The website looks and feels like a government website. </p>
<p>The campaign research identified a range of barriers to girls engaging in physical activity. Girls said they felt self-conscious. They find getting hot and sweaty uncomfortable. They feel embarrassed if they are not as capable as other girls. </p>
<p>The “activities” page invites girls to “Check out the activities and apps that can help get you moving.” This is where a girl might look for the practical information she needs if she is thinking about participating in a new activity. </p>
<p>What does she get if she looks for “tips”?</p>
<ul>
<li>Group exercise: “Depending on where you go, you may need a membership.” (that’s it – that’s all the “tips” you get)</li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=257&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=257&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=257&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=323&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=323&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114195/original/image-20160308-15291-oldd0r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=323&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>
</figcaption>
</figure>
<ul>
<li>Rugby: “Try side-stepping the opposition.” </li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=479&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=479&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114196/original/image-20160308-15305-1m9tbdl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=479&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>
</figcaption>
</figure>
<p>What does she get if she clicks on “apps”?</p>
<ul>
<li>“Search for apps in your app store to help you get physically active.”</li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=136&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=136&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=136&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=171&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=171&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114194/original/image-20160308-15291-1dh6vek.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=171&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>
</figcaption>
</figure>
<p>The section on “tips for girls” and “tips for parents” is similarly bland.</p>
<p>All of the media ads direct girls to the website to “get started”.
So, the website should inspire and empower. I would expect to find:</p>
<ul>
<li> tips for fitting physical activity into her busy day</li>
<li> a downloadable/printable schedule so she can set goals and targets</li>
<li> instructional videos or demonstrations</li>
<li> some recommended (free) apps – or even a dedicated Girls Make Your Move app.</li>
</ul>
<p>The social media isn’t very social. The website (and other materials) include links to social media – Instagram, Facebook and Twitter. I clicked on Facebook, and I got… the Australian Department of Health’s official <a href="https://www.facebook.com/healthgovau">Facebook page</a>. I clicked on Twitter and I got… the Australian Department of Health’s official <a href="https://twitter.com/healthgovau">Twitter page</a>.</p>
<h2>(Who) is it likely to motivate?</h2>
<p>Reviews of <a href="http://www.ncbi.nlm.nih.gov/pubmed/23079180">physical activity media campaigns</a> have generally found we all see them and remember them, but they don’t change our behaviour. </p>
<p>Most Australians remember Norm but increasing numbers of us share his iconic body shape.</p>
<p>Media campaigns are an important step in <a href="http://www.sciencedirect.com/science/article/pii/S0149718906000565">raising awareness</a> of an issue, like the fact that girls need to be more active. </p>
<p>For a campaign to lead to behaviour change it needs to do a lot more than tell us what to do. It needs to show us how to do it, and provide us with tools and resources. The Australian national <a href="http://www.healthyactive.gov.au/internet/healthyactive/publishing.nsf/Content/CD99B2A715DB9214CA2572DC001855A8/$File/getmoving-eval-jul07.pdf">Get Moving campaign</a> had spectacular awareness – 99% of children and 96% of teenagers saw the campaign – but it didn’t make them more active.</p>
<p>These ads are likely to engage the girls who enjoy being active but have fallen out of the habit, by reminding them how much fun they have. The public events, especially those that feature high-profile athletes, will also reach and engage this target group.</p>
<p>On their own, they may not have much of an impact on those who are disinterested in physical activity. They need to be supported by materials that increase girls’ beliefs in their ability and give them tools for <a href="http://www.tandfonline.com/doi/abs/10.1080/08870446.2015.1070157#.VtzXKoQxTdk">planning to be more active</a>. </p>
<p>Todays’ teenage girls have more friends on Facebook than in the real world and spend more time in cyberspace than in the fresh air. A social media presence should enable girls to connect, share and inspire each other. It should also provide a place for the two-way communication that today’s young people expect if they are going to engage with a campaign.</p>
<p>On Instagram, where it does have a unique presence, Girls Make Your Move has already amassed over 2,000 followers. Hopefully, this will inspire the cautious government to stick a few more toes in the water and build a Facebook page and Twitter profile that engages with young women.</p><img src="https://counter.theconversation.com/content/55638/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sandra Jones is an Australian Research Council Future Fellow. She receives funding from the ARC, Healthway, WA Drug and Alcohol Office, Cancer Australia, NBCF, FARE, VicHealth, Medibank, Cancer Council Victoria, Sax Institute and Movember.
</span></em></p>The Girls Make Your Move ads need to be supported by materials that increase girls’ beliefs in their ability and give them tools for planning to be more active.Sandra Jones, Professor and Director of the Centre for Health and Social Research, Australian Catholic UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/548882016-02-29T02:49:55Z2016-02-29T02:49:55ZHealth Check: should children and adolescents lift weights?<figure><img src="https://images.theconversation.com/files/112266/original/image-20160222-25861-iil82k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A survey of parents found many weren't keen on their kids lifting weights, but the evidence says they should.</span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>We all know exercise is an essential part of a healthy lifestyle, and most will agree kids should be doing more of it. However, a <a href="http://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-015-2328-7">recent study</a> found while parents are positive about their children engaging in aerobic activities (running, playing sports), they have much more negative views when it comes to strength exercises. </p>
<p>But these concerns are not backed up by the evidence.</p>
<p>People often see strength training as just lifting heavy weights in a gym, but strength training can be done in a wide variety of ways, including using just your body weight. Strength training can also incorporate medicine balls, sand bags, elastic resistance bands and weighted sleds.</p>
<h2>Myth 1: high risk of injury</h2>
<p>Until recent years, there was very little data on injuries associated with youth strength training. What did exist, however, were a handful of <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1478294/?page=1">case reports</a> outlining serious injuries from misuse of weight training equipment, and a few <a href="http://www.ncbi.nlm.nih.gov/pubmed/6634267">small</a> studies reporting high injury rates in competitive youth weightlifting and powerlifting programs.</p>
<p>In 1990, the American Academy of Pediatrics cautiously <a href="http://pediatrics.aappublications.org/content/pediatrics/86/5/801.full.pdf">recommended</a> against participation in strength training prior to reaching physical maturity. This report was actually referring to weightlifting, powerlifting and bodybuilding, which involve the use of maximal loads and highly technical lifting movements that had never been recommended for young people.</p>
<p>Regardless, the message that “weights are bad for young people” took hold and the public distrust of strength training lingered on. We now know that supervised and age-appropriate strength training is <a href="http://bjsm.bmj.com/content/44/1/56.short">a safe activity</a> for children and adolescents, and a good way to improve muscular fitness, body composition and psychological health.</p>
<p>In fact, appropriately conducted strength training programs have a much <a href="http://bjsm.bmj.com/content/44/1/56.short">lower risk</a> of injury than many popular youth sports like soccer, football or basketball – activities that parents happily enrol their children in year after year. Ironically, participation in strength training can actually <a href="http://www.ncbi.nlm.nih.gov/pubmed/20547668/">reduce the risk</a> of children being injured when they play sports.</p>
<h2>Myth 2: lifting weights stunts growth</h2>
<p>You’ve probably heard at some point that strength training can stunt growth in children. This claim is based on an enduring belief that strength training causes damage to “growth plates”. </p>
<p>Growth plates (or epiphyseal plates) are the cartilaginous areas of growing tissue at the ends of long bones such as the femur and radius. These plates turn into hardened bone when young people reach physical maturity, but are softer during development and are therefore more susceptible to damage. </p>
<p>While scary to consider, growth plate injuries are actually quite common, accounting for around 15 to 30% of all bone injuries in children. Most injuries resolve completely with treatment, but on rare occasions they can result in growth abnormalities. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=551&fit=crop&dpr=1 754w, https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=551&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/112268/original/image-20160222-25871-4gnt5h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=551&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Strength training in youth won’t stunt growth, despite what many believe.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>It’s not quite clear why strength training is considered more likely to damage growth plates than other physical activities, but this common misconception has withstood the test of time. At least part of the reason seems to be due to a misinterpretation of why elite athletes in sports like weightlifting and gymnastics are consistently short. </p>
<p>Long story short (pun intended), small athletes are better suited to these sports, in the same way that being tall is an advantage in basketball. Therefore, short athletes are more highly represented at the upper levels of competition, where we tend to notice them. This has nothing to do with high volumes of training or lifting heavy weights. While strength training often gets the blame, the truth is growth-plate injuries occur much more often during <a href="http://bjsm.bmj.com/content/40/9/749.full.pdf+html">organised sports</a>.</p>
<p>Extensive <a href="http://journals.lww.com/cjsportsmed/Abstract/2006/11000/Weight_Training_in_Youth_Growth,_Maturation,_and.5.aspx">research</a> on the safety of youth strength training programs has found no evidence to suggest they have adverse effects on growth, nor is there any evidence that strength training during the growing years impacts final adult height.</p>
<h2>Do children and teenagers need strength training?</h2>
<p>The <a href="http://www.who.int/dietphysicalactivity/factsheet_young_people/en/">World Health Organisation</a>, <a href="http://intl-pediatrics.aappublications.org/content/121/4/835.full">American Academy of Pediatrics</a> and the Australian government all agree muscle-strengthening physical activities are important for the health and well-being of young people. In fact, <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/health-pubhlth-strateg-phys-act-guidelines#apa1317">government guidelines</a> explicitly recommend young people (aged five to 18 years) participate in muscle- and bone-strengthening activities at least three days a week. </p>
<p>These recommendations are based on <a href="http://bjsm.bmj.com/content/early/2013/09/20/bjsports-2013-092952.short">a large body of evidence</a> demonstrating the unique benefits of strength training. In a <a href="http://www.ncbi.nlm.nih.gov/pubmed/24788950">review of prior research</a>, we found stronger kids have a healthier heart, lower body fat, stronger bones and higher self-esteem.</p>
<p>Importantly, the evidence seems to suggest the healthiest youngsters will be those who participate in a variety of activities, targeting not just the heart and lungs, but also the muscles, joints and bones. </p>
<p>So children and adolescents can and should “lift weights”, as long as it’s done properly. Experts recommend beginners start with body weight exercises and add weight only when they are competent at the movements. If using external weights, training should be supervised by a qualified instructor. Exercises should be matched to the age and experience level of the individual.</p>
<p>Maximal lifts before reaching physical maturity (usually around 16 years) are still not recommended. The focus during childhood and early adolescence should be on <a href="http://journals.lww.com/nsca-jscr/Abstract/2014/05000/Development,_Test_Retest_Reliability,_and.25.aspx">developing movement skills</a> and building strength endurance (the ability for muscles to work repeatedly). This will provide the right foundation for improving maximal strength in later years, when individuals have the competence, confidence and experience to perform the lifts safely.</p>
<p>Simple and effective body weight exercises young people can <a href="http://greatist.com/fitness/50-bodyweight-exercises-you-can-do-anywhere">start with</a> include push-ups, squats, lunges, planks (holding body horizontal to the ground, with weight resting on your hands/forearms and toes to strengthen the core), bear crawls (crawling on hands and feet to work out the whole body), mountain climbers (in plank position, bring one knee at a time up to your chest to strengthen core) and the superman (lie flat on stomach with arms extended overhead and lift arms and legs off the floor to strengthen lower back).</p><img src="https://counter.theconversation.com/content/54888/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jordan Smith 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>A recent study found while parents are positive about their children engaging in aerobic activities (running, playing sports), they have much more negative views when it comes to strength exercises.Jordan Smith, Lecturer , University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/418202015-09-14T04:06:47Z2015-09-14T04:06:47ZHealth Check: why do my muscles ache the day after exercise?<figure><img src="https://images.theconversation.com/files/93025/original/image-20150826-1619-1c5jqfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Think of it as a useful signal from your body. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-284130629/stock-photo-runner-athlete-running-at-seaside-road-woman-fitness-jogging-workout-wellness-concept.html?src=lj4z7mA8NN8aEZdR2_huow-1-147">lzf/Shutterstock</a></span></figcaption></figure><p>It’s normal to experience muscle pain after exercising if it’s been a while since you were active or performed a certain movement. This type of pain – called delayed onset muscle soreness or DOMS – generally develops several hours later and exacerbates over the next few days. </p>
<p>The exercise that induces DOMS consists of eccentric (lengthening) muscle contractions in which contracting muscles are lengthened. Walking down a set of stairs or slope, where front thigh muscles are lengthened when supporting the body weight, is one example of eccentric exercise. </p>
<p>Another is using weights, such as a dumbbells. When lowering a heavy object slowly from an elbow flexed to an extended position, the muscles to flex the elbow joint perform eccentric exercise, since the external load (dumbbell) is greater than the force generated by the muscle. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=707&fit=crop&dpr=1 600w, https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=707&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=707&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=889&fit=crop&dpr=1 754w, https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=889&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/94586/original/image-20150914-19851-6mw13m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=889&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>
</figcaption>
</figure>
<p>Exercise consisting of mainly concentric (shortening) contractions, where muscles contract and are shortened, such as walking up stairs and lifting a dumbbell, does not induce DOMS at all.</p>
<p>DOMS is technically considered an indicator of “muscle damage”, as muscle function decreases and, in some cases, muscle-specific proteins increase in the blood, indicating plasma membrane damage. But it appears that very few muscle fibres are actually injured or destroyed (less than 1% of total muscle fibres). </p>
<p>Interestingly, other structures such as fascia (the sheath of tissue surrounding the muscle) and connective tissue within the muscle appear to be more affected by eccentric contractions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=304&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=304&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=304&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=381&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=381&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93021/original/image-20150826-1585-1fi39k6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=381&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Structure of skeletal muscle.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-127770863/stock-vector-structure-of-skeletal-muscle-vector-illustration.html?src=n7zfNSRvF99EcG_Tyi2iEQ-1-21">Designua/Shutterstock</a></span>
</figcaption>
</figure>
<p>A study my colleagues and I <a href="http://www.ncbi.nlm.nih.gov/pubmed/25519953">recently published</a> tested the hypothesis that fascia would become more sensitive than muscle when DOMS is induced. We probed the muscles of volunteer eccentric exercisers with an acupuncture needle designed to introduce a steadily increasing electrical current from its tip, until they reported muscle pain.</p>
<p>The results showed that DOMS was associated with the increased sensitivity of muscle fascia to the stimulus, suggesting the source of pain is fascia (connective tissue) rather than the muscle fibres themselves. </p>
<p>We still don’t know how eccentric contractions affect connective tissue surrounding muscle fibres. It’s possible they have different levels of elasticity. So, as the contracting muscle is stretched, a <a href="https://en.wikipedia.org/wiki/Shear_force">shear force</a> may develop between muscle fibres and their surrounding connective tissue. This may damage the structure and cause inflammation.</p>
<p>It’s still a mystery why there’s a delay between the exercise and muscle soreness. Researchers speculate that it’s due to the time it takes for inflammation to develop after the micro-injury.</p>
<p>It doesn’t appear that DOMS is a warning sign not to move the affected muscles, since moving the muscles ameliorates the pain and does not hamper the recovery. It may be that DOMS is a simple message from the body that the muscle lacked a good stimulus for a while, which it received. </p>
<p>But is it necessary for developing bigger and stronger muscles? </p>
<p>There’s no scientific evidence to support the theory of “no pain no gain”. <a href="http://www.ncbi.nlm.nih.gov/pubmed/22344059">Research shows</a> eccentric exercise training produces greater increases in muscle strength and size when compared with concentric exercise training, but this is not necessarily associated with “muscle damage.” </p>
<p>Don’t be afraid of DOMS, although it could bother you for several days after exercise. DOMS reduces when the same eccentric exercise is repeated. If the intensity and volume of eccentric exercise are gradually increased, you can minimise DOMS. </p>
<p>In the meantime, think of DOMS as a useful signal from your body.</p><img src="https://counter.theconversation.com/content/41820/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>It’s normal to experience muscle pain after exercising if it’s been a while since you were active or performed a certain movement.Ken Nosaka, Professor of Exercise and Sports Science, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/443142015-09-04T04:24:00Z2015-09-04T04:24:00ZExpensive running shoes don’t prevent injuries, but comfortable ones might<figure><img src="https://images.theconversation.com/files/92224/original/image-20150818-12389-1xvcora.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many runners opt for expensive footwear - but are they worth it?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/fotografgruppen/4017135689/">Fotografgruppen Fotografgruppen/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>If you’ve ever sustained an injury from running, you’re not alone; about half of all adults who run regularly will get injured <a href="http://bjsm.bmj.com/content/41/8/469.long">each year</a>. And if that’s not enough to put you off, having a history of previous injuries is one of the strongest risk factors for <a href="http://bjsm.bmj.com/content/41/8/469.long">getting injured again</a>. </p>
<p>So it’s no surprise that avoiding injuries is a priority for runners. </p>
<p>One third of runners are so concerned about this, in fact, that they’ll <a href="http://journals.lww.com/nsca-jscr/Abstract/2012/08000/Primitive_Running___A_Survey_Analysis_of_Runners_.2.aspx">ditch their plain old running shoes</a> for fancier footwear they feel is safer and will improve their performance. But do the promises made by global footwear companies about their expensive running shoes stack up? </p>
<h2>The evidence</h2>
<p>The first thing we need to address is whether the modern running shoe’s extra safety features, such as increased stability or extra cushioning, are protecting people from injury. Not very much, according to <a href="http://bjsm.bmj.com/content/43/3/159.short">a provocative 2009 review</a> that highlighted a lack of research testing exactly this. </p>
<p>More evidence has emerged since, but we’re still none the wiser. </p>
<p>One study that randomly allocated 81 female runners to shoes with different levels of stability based on their foot posture (pronated, neutral, supinated) found <a href="http://bjsm.bmj.com/content/early/2010/06/26/bjsm.2009.069849.short">no difference</a> in injury rates during a 13-week training program. Another, which randomly allocated hard or soft-soled shoes to 247 runners, also found <a href="http://bjsm.bmj.com/content/early/2013/09/16/bjsports-2013-092613.short?rss=1">no difference</a> in injury rates over a five-month period.</p>
<p>But despite the current state of research literature indicating no clear benefits of running shoes with extra safety features, we’re bombarded by claims from global footwear companies about the advantages of their expensive products. </p>
<p>When we dissect the content of the claims made by these manufacturers, we see a recurrence of vague terms, teetering dangerously between the medical and sportswear industries. </p>
<p>Words conjuring imagery of sport and performance such as “zoom”, “fast”, “elite” and “launch pad” are littered among others suggesting direct benefits from their shoes, such as “better” and “safer”. Terms once synonymous with expensive cars are also adopted by global footwear companies, who claim their products offer the most “<a href="http://www.asics.com.au/gel-nimbus">fluid</a>”, “<a href="http://www.mizunousa.com/Running/Products/WAVE-RIDER-18-MENS">smooth</a>” or “<a href="http://www.brooksrunning.com/en_us/Transcend.html">plush</a>” experience for runners. </p>
<h2>Problematic claims</h2>
<p>The problem is compounded by running footwear companies using “surrogate outcomes” to support claims that their newest technology <em>may</em> reduce risk of a running-related injury. But what’s a “<a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=4225188&fileId=S0266462300009594">surrogate outcome</a>”? </p>
<p>If we want to test whether a new model of footwear, or piece of footwear technology, actually protects against injury, we’d measure – in a controlled study – how many people get injured wearing (and not wearing) the product. </p>
<p>But tracking who does and doesn’t get injured over an extended period is a time-consuming and expensive exercise. To circumvent inconvenience and cost, we could instead measure what effect the new footwear has on outcomes that <em>may</em> relate to increasing risk of injury.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92223/original/image-20150818-12372-if6efg.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">
<figcaption>
<span class="caption">There’s no clear evidence to suggest expensive running shoes prevent injury.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/22226011@N02/8080159041/">nprpdx/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>We may, for instance, measure how much they reduce your foot from rolling in (pronating) or soften your impact with the ground (ground reaction forces), as a “surrogate” for measuring injury. But these aren’t strong surrogates because neither foot pronation nor high ground reaction forces are strong <a href="http://bjsm.bmj.com/content/early/2015/07/28/bjsports-2015-095054.short?rss=1">risk factors</a> for running-related injuries. </p>
<p>The reason for measuring surrogate outcomes in place of actual ones then, is that they’re cheaper, more convenient and provide indirect support for marketing claims about new footwear products. </p>
<h2>Inviting controversy</h2>
<p>In the search to gain advantage in an increasingly competitive marketplace, footwear companies are forever pushing the boundaries with their claims. And when they slip up, the results can be disastrous. </p>
<p>In 2012, <a href="http://www.universalhub.com/files/vibram-complaint.pdf">a class-action lawsuit</a> was made against Vibram USA, the company that makes the FiveFingers running shoes, the glove-like footwear at the epicentre of the “natural” or “barefoot” running phenomenon. </p>
<p>The case was based on unsupported and deceptive claims of “strengthened foot and leg muscles”, “reduced risk of injury” and improved “balance and agility” and “spinal posture” from wearing the shoes. Vibram USA settled, offering refunds to customers and discontinuing the use of these claims about its footwear. </p>
<p>Similarly, promises of more <a href="https://www.youtube.com/watch?v=m9ZaAkYEES8">toned buttocks</a> from walking in Reebok’s EasyTone shoes were found to be deceptive and <a href="https://www.ftc.gov/news-events/press-releases/2011/09/reebok-pay-25-million-customer-refunds-settle-ftc-charges">misleading</a> by the US Federal Trade Commission. </p>
<p>Reebok was required to pay US$25 million in customer refunds and banned from making unsubstantiated health and fitness claims relating to its “toning” footwear.</p>
<h2>The solution</h2>
<p>Selecting running shoes based on the purported benefits of certain foot protective features, such as “cushioning” and “motion control”, offers no protection against running-related injuries. In fact, we may have reached a point where running shoes are being over-engineered in order to meet market trends, rather than being designed to make running safer. </p>
<p>But where does that leave people faced with the task of deciding the right shoe for them? Interestingly, the solution may lie in not what you think the shoes may do for you, but how comfortable they feel.</p>
<p>In the absence of strong evidence that modern running shoe features reduce injury rates, <a href="http://bjsm.bmj.com/content/early/2015/07/28/bjsports-2015-095054.full.pdf+html">comfort</a> may be more important than other factors, such as reduced foot pronation and shoe cushioning. </p>
<p>Although footwear comfort is <a href="http://europepmc.org/abstract/med/20216463">difficult to define and quantify</a>, most people are able to sense whether the shoes they’re trying on are comfortable or not. Support, fit and foot alignment are among factors that influence feeling comfortable in a pair of shoes. </p>
<p><a href="https://www.researchgate.net/profile/Annegret_Muendermann2/publication/10658602_Relationship_between_footwear_comfort_of_shoe_inserts_and_anthropometric_and_sensory_factors/links/004635182b4c8cf136000000.pdf">Comfortable running shoes</a> are associated with lower frequency of injuries than uncomfortable shoes. This suggests your body may be the best judge of footwear that’s ideal for you. </p>
<p>The next time you feel bamboozled by the cornucopia of gels, foams and rubbers in running shoes, arm yourself with the knowledge that comfort is one of the best determinants of whether a pair of shoes is right for you. And that may work best for preventing injuries, your wallet and your peace of mind.</p><img src="https://counter.theconversation.com/content/44314/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Arnold has received research funding from Sports Medicine Australia.</span></em></p>Since avoiding injuries is a priority for runners, many end up buying expensive footwear for their purported safety features. But do the promises made by global footwear companies stack up?John Arnold, Lecturer in Exercise Science, University of South AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/461972015-08-31T04:12:03Z2015-08-31T04:12:03ZHealth Check: do you need to stretch before and after exercise?<figure><img src="https://images.theconversation.com/files/92040/original/image-20150817-5085-1ktm65b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some people believe stretching reduces the risk of injury, reduces soreness experienced after exercise, or enhances sporting performance.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/nataliejohnson/2585333542/">natalie/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>Many people stretch when they exercise or play sport. Others don’t stretch but feel they should. And some people don’t see any reason to stretch at all.</p>
<p>The reasons for stretching are diverse. Most people think stretching makes them more flexible. Some believe stretching reduces the risk of injury, reduces soreness experienced after exercise, or enhances sporting performance. Optimists think stretching does all these things.</p>
<p>But do we really need to stretch when we exercise? And does stretching increase flexibility, reduce the risk of injury, reduce soreness and enhance sporting performance? The answer is neither yes nor no.</p>
<h2>Randomised trials</h2>
<p>The only way researchers can get a really clear idea of the effects of stretching is to conduct randomised trials. (<a href="http://www.testingtreatments.org/tt-main-text/">Here’s a clear explanation</a> of why randomised trials are special that you can read later.) </p>
<p>In randomised trials, a lottery is used to allocate each participant to either receive the treatment (in this case, stretching) or not. Then the outcomes (injury, muscle soreness or sporting performance) of the trial participants who stretched are compared with the outcomes of those who didn’t. The difference in the outcomes of the two groups tells us about the effects of stretching.</p>
<p>The <a href="http://www.ncbi.nlm.nih.gov/pubmed/10694106">first two trials</a> of the effects of stretching on risk of injury, <a href="http://www.ncbi.nlm.nih.gov/pubmed/11676730">conducted on 2,631 army recruits</a>, showed three months of routine stretching before exercise didn’t appreciably reduce injury risk. A more recent <a href="http://bjsm.bmj.com/content/early/2009/06/11/bjsm.2009.062232.abstract">trial</a> on 2,377 recreationally active people had very similar findings: three months of regular stretching had little or no effect on risk. </p>
<p>Together, these trials strongly suggest stretching doesn’t appreciably reduce injury risk.</p>
<p>A number of other randomised trials have investigated the effects of stretching before and after physical activity on the soreness experienced after exercise. They suggest stretching does reduce soreness, but the effect is very small. </p>
<p><a href="http://www.cochrane.org/CD004577/MUSKINJ_stretching-to-prevent-or-reduce-muscle-soreness-after-exercise">A review</a> of such trials concluded that:</p>
<blockquote>
<p>muscle stretching, whether conducted before, after, or before and after exercise, does not produce clinically important reductions in delayed-onset muscle soreness in healthy adults.</p>
</blockquote>
<h2>Flexibility and strength</h2>
<p>The effect of stretching on sporting performance is less clear, or at least more complex. </p>
<p>Few randomised trials have measured sporting performance as an outcome. Instead, most have studied the effect of stretching on two intermediaries that are likely to affect sporting performance: flexibility and the ability of muscles to generate force. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92043/original/image-20150817-5121-tj4a7f.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">Ballet dancers and yoga teachers, who stretch a lot, tend to be more flexible than the rest of us.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/quinnanya/5282138008/">Quinn Dombrowski/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>To understand the effects of stretching on flexibility and muscle force generation, it’s necessary to distinguish its acute and chronic effects. Acute effects manifest immediately after a stretch whereas chronic effects manifest only after repeated bouts of stretching, perhaps over months or years.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/11470302">Stretching acutely increases flexibility</a>: after just a few seconds or a few minutes of stretching, joints move further and resist movement less. But this effect is transient. Once the stretching stops, flexibility returns to pre-stretch levels. And recovery is largely complete within a few minutes of finishing the stretch.</p>
<p>It’s possible, but less certain, that stretching also has chronic effects on flexibility. Regular stretching could stimulate adaptations of muscles and other tissues that bring about lasting increases in flexibility. </p>
<p>Everyday observations suggest that’s true, because ballet dancers and yoga teachers, who stretch a lot, tend to be more flexible than the rest of us. But, while it seems obvious that regular stretching makes people more flexible, it has proved remarkably difficult to demonstrate that in controlled experiments. </p>
<p>Stretching does make <a href="http://www.ncbi.nlm.nih.gov/pubmed/8951730">people tolerate stretch more</a>. That is, it makes people feel able to get into more stretched positions. And this increase in stretch tolerance may make people feel more flexible even when they’re not.</p>
<p>Either way, the effects of stretching on flexibility – acute or chronic – could be exploited to enhance performance of some sports. It seems likely that hurdlers or gymnasts, for instance, could perform better if they were more flexible. More generally, it appears likely that stretching could increase performance in sports that require flexibility.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92042/original/image-20150817-5110-1ojw9kf.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">It seems likely that hurdlers could perform better if they were more flexible.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/piratepix2/4540836076/">Melinda Huntley/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>The other way stretching could affect performance is through its effects on the ability of muscles to produce force. The <a href="http://www.ncbi.nlm.nih.gov/pubmed/22316148">clearest conclusion</a> that arises from studies on humans is that stretching typically produces a small, temporary reduction in the strength of stretched muscles. </p>
<p>This suggests it may be unwise to stretch muscles immediately prior to sport if it requires generation of large muscle forces. </p>
<h2>To stretch or not to stretch?</h2>
<p>For recreationally active people, these research findings suggest stretching might have a very small benefit and probably won’t do any harm. If you like stretching, stretch. If you don’t like stretching, don’t do it and don’t feel guilty about not doing it. </p>
<p>For high-level athletes, there’s more at stake and the decision is harder. Stretching might increase performance in sports that require lots of flexibility but could temporarily decrease muscle strength; it makes more sense to stretch if you’re a hurdler than if you’re a weightlifter.</p>
<p>These conclusions come with some caveats. First, most of the research into the effects of stretching has investigated the effects of “static” stretching – stretches that are applied and sustained for a short while. There are <a href="http://www.livestrong.com/article/539154-7-types-of-stretching-exercises/">many other ways of stretching</a>, but most have been the subject of relatively little research, or only poor-quality research. </p>
<p>Another caveat is that, while quite a lot is known about the acute effects of stretching, much less is known about its chronic effects. No one has attempted to conduct a randomised trial of the effects of regular stretching over periods of years. </p>
<p>It may be that, in the long term, regular stretching has important effects. Then again, it may be that the long-term effects of stretching are harmful, or that there’s no long-term effect at all: we just don’t know. </p>
<p>Similarly, good evidence of the superiority of one method of stretching over another, or of the long-term effects of particular kinds of stretching, doesn’t exist.</p>
<p>To finish on a more positive note: while it appears that stretching doesn’t appreciably reduce risk of injury, there’s good evidence that <a href="http://www.biomedcentral.com/1741-7015/10/75">warming up does</a>. An intensive, well-structured, active warm-up can substantially reduce risk of injury, so try doing that the next time you exercise.</p><img src="https://counter.theconversation.com/content/46197/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rob Herbert received funding from the NSW Sporting Injuries Committee Research and Injury Prevention Scheme to support one of the trials reported here. He was one of the investigators in several of the studies cited in this article.</span></em></p>Many people stretch when they exercise or play sport. Others don’t stretch but feel they should. And some people don’t see any reason to stretch at all.Rob Herbert, Senior Principal Research Fellow, Neuroscience Research AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/372862015-03-02T03:42:59Z2015-03-02T03:42:59ZHealth Check: how to exercise safely in the heat<figure><img src="https://images.theconversation.com/files/73121/original/image-20150226-1807-hzlmxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If you're not regularly active, extreme exercise and exercise in extreme heat is unwise.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-239818048/stock-photo-tired-woman-runner-taking-a-rest-after-running-hard-in-countryside-road-sweaty-athlete-after.html?src=jQxMS54jYe8X9RUXRnMCdQ-3-127&ws=1">lzf/Shutterstock</a></span></figcaption></figure><p>Exercise alone can be hard, but exercising in the heat is a whole lot harder. Put simply, this is due to the balance between how much heat the body generates and how much it is capable of losing.</p>
<p>Human core body temperature typically remains around 36.5°C to 37°C, with small fluctuations across the day. Larger changes above 40°C can be dangerous. </p>
<p>Fortunately, humans are relatively well-adapted to dealing with the heat. One theory is that humans evolved a <a href="https://www.youtube.com/watch?v=826HMLoiE_o">survival advantage as hunters</a> because they could outlast animals that were less able to manage long periods of <a href="http://www.nature.com/nature/journal/v432/n7015/abs/nature03052.html">exertion under hot conditions</a>. </p>
<h2>How do we regulate our temperature?</h2>
<p><strong>1. Radiation:</strong> There are so many small blood vessels in the skin that, in total, they can receive up to 60% of output from the heart at rest. </p>
<p>As blood flows from the core of the body to the skin, opening of these small blood vessels allows more surface area for heat exchange with the environment. </p>
<p>Radiation of heat occurs when the surrounding environment is less hot than the skin surface. At rest in a cool environment, 60% of heat loss is by <a href="http://link.springer.com/article/10.1007/BF00596389">radiation</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=384&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=384&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=384&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=482&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=482&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73139/original/image-20150226-1814-1fsca4t.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=482&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-177791000/stock-vector-vector-illustration-of-diagram-of-human-skin-anatomy.html?src=_xkOoBHTHcJ67yFbZbDW-A-1-1&ws=1">stockshoppe/Shutterstock</a></span>
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</figure>
<p><strong>2. Evaporation:</strong> As core temperature rises, sweat glands in the skin are activated, promoting heat loss via the combined processes of <a href="https://theconversation.com/want-to-keep-cool-on-hot-summer-days-heres-how-34489">convection, conduction and evaporation</a>. </p>
<p>These forms of heat exchange become more important as heat production rises (such as during exercise), and as the environment becomes hotter and radiation less effective.</p>
<h2>Why is it so hard to exercise in the heat?</h2>
<p>Muscles that are active during exercise demand more energy and, consequently, increased blood supply and delivery of oxygen. This means the heart has to work harder to re-circulate blood to the active muscles. </p>
<p>Exercising muscles also generate heat, as a by-product of chemical reactions inside cells. This increases core body temperature which, if not compensated for, can compromise the ongoing function of the central nervous system and/or muscle cells themselves. </p>
<p>To lose heat, blood needs to be sent to the small arteries under the skin surface, so that heat transfer can take place via radiation. Sweating alone is relatively ineffective if this re-distribution of blood does not occur concurrently. </p>
<p>So when exercise occurs under circumstances where heat loss is challenged (because the gradient between skin and environmental temperatures is narrow), more blood needs to be directed to the skin at the same time as this blood is needed in the muscles to increase workload. </p>
<p>A competition therefore develops between the skin and working muscles for the limited maximal blood flow that the heart can manage.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73122/original/image-20150226-1819-l51osa.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">Acclimatisation can increase a person’s capacity to heat loss.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-201434165/stock-photo-man-fitness-runner-drinking-and-splashing-water-in-his-face-funny-image-of-handsome-male.html?src=jQxMS54jYe8X9RUXRnMCdQ-2-73&ws=1">Milles Studio/Shutterstock</a></span>
</figcaption>
</figure>
<p>Different theories explain fatigue (the point at which you cannot maintain exercise duration and/or intensity) as either the inability to sustain oxygen delivery to the muscle in the face of thermoregulatory demand, or an inability to control body and brain temperature during exercise in hot environments. </p>
<p>The causes of fatigue are of great interest to exercise scientists concerned with sport and workplace performance. We know that acclimation (the process of repeated exercise in hot conditions) can enhance an individual’s capacity for heat loss and, therefore, improve exercise performance and delay fatigue. </p>
<p>Several steps in the exercise and thermoregulatory chain are amenable to adaptations that improve performance, including enhanced <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3006409/">function</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/21131471">structure</a> of the blood vessels, the function and size of the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3240883/">heart</a> and even <a href="http://www.ncbi.nlm.nih.gov/pubmed/1798375">blood volume</a> itself.</p>
<h2>Who is at risk of heat stroke?</h2>
<p>Heat stroke is a serious illness and those most at risk include adults aged over 65 years, babies and young children, pregnant women, people with existing medical conditions and those on particular medications. Most obviously, those who already have heart problems are at particular risk. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73137/original/image-20150226-1758-efnocd.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">
<figcaption>
<span class="caption">Older people are at greater risk of heat-related illness.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-141240130/stock-photo-portrait-an-elderly-woman.html?src=cQBoG_PFJsn_PXbyX5_qpQ-1-133&ws=1">De Visu/Shutterstock</a></span>
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</figure>
<p>Such is the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC192832/">risk of heat illness</a> that 10,000 excess deaths occurred during a heatwave in Europe in 2003. </p>
<p>In the Australian summer of 2009, hot conditions in Victoria and South Australia were linked with higher rates of illness and more than 200 extra deaths than would normally occur, particularly among the elderly and those with heart disease.</p>
<p>Early signs of heat exhaustion can include dizziness, headache and nausea. More severe cases of heat stroke involve hot dry skin with (paradoxically) no sweating, confusion and fainting.</p>
<p>Sports Medicine Australia has produced a <a href="http://sma.org.au/wp-content/uploads/2009/05/hot-weather-guidelines-web-download-doc-2007.pdf">helpful guide</a> to performance of sport or exercise in hot weather, which details the risk and symptoms of heat illness. </p>
<h2>What’s the best way to deal with the heat?</h2>
<p>For professional athletes, exercising in warm conditions can improve performance and is sometimes essential to prepare for different environmental conditions, such as preparing for an Olympic games in a hot country. </p>
<p>Regardless, it’s important to take precautions to reduce the likelihood of heat illness by staying hydrated, wearing appropriate clothing and knowing your limits.</p>
<p>For people who don’t exercise regularly or those who are at increased risk of heat-related illness, avoid exercising in the heat, such as the middle of the day in summer or rooms with poor air circulation. </p>
<p>Instead, opt for a prescribed, gradual and incremental exercise program that improves your cardiovascular and thermoregulatory tolerance. Gradual and repeated heat exposure, even in the absence of exercise, may also be <a href="http://www.ncbi.nlm.nih.gov/pubmed/25705824">good for your health</a>. </p>
<p>The good news is that even exercise in normal or cool conditions will improve thermoregulatory capacity and resilience under hot conditions. But if it’s out of the ordinary for you, extreme exercise or exercise in extremes, is equally unwise.</p><img src="https://counter.theconversation.com/content/37286/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Howard Carter receives funding from the National Heart Foundation of Australia.</span></em></p><p class="fine-print"><em><span>Daniel Green receives funding from the Australian Research Council, National Heath and Medical Research Council, National Heart Foundation of Australia.</span></em></p>Exercise alone can be hard, but exercising in the heat is a whole lot harder. Put simply, this is due to the balance between how much heat the body generates and how much it is capable of losing.Howard Carter, Research Associate, School of Sports Science, Exercise and Health, The University of Western AustraliaDaniel Green, Winthrop Professor, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/368392015-02-01T19:07:06Z2015-02-01T19:07:06ZJust not cricket – how climate change will make sport more risky<p>Sport is fundamental to Australia’s society, culture and economy. But how would we cope when the rising heat threatens some of our most beloved pastimes? </p>
<p>A <a href="http://www.climateinstitute.org.au/sport-and-climate.html">new report</a> from the Climate Institute urges sports administrators to take the issue of heat stress seriously and to take steps to safeguard players, both professional and grassroots, from the health dangers.</p>
<h2>Sport is good for us</h2>
<p>As the new report (on which I was an advisor) points out, 80% of Australians aged 15 and over engage in sporting activities, more than two-thirds of schoolchildren play organised sport outside school, and more than 7.5 million Australians attend at least one sporting event a year. Each year, sport contributes more than A$12.5 billion to the economy and employs more than 75,000 people.</p>
<p>The <a href="http://www.cmaj.ca/content/174/6/801.abstract">documented benefits</a> extend beyond mere economics. Sport guards against obesity, cardiovascular disease and stroke, respiratory disorders, cancer, and type-2 diabetes, and boosts fitness, strength, mobility, and independence in later life. It aids <a href="http://www.apocpcontrol.com/paper_file/issue_abs/Volume8_No3/325-338%20b_Kruk14.pdf">mental wellbeing</a>, reduces stress, anxiety and depression, teaches fair play and leadership skills, builds self-esteem, and helps meet new friends and mentors.</p>
<p>Add to that the national feelgood factor when one of our sporting stars excels on the world stage, and it’s fair to say that sport is a good thing.</p>
<h2>It is getting hotter</h2>
<p><a href="http://www.climatechangeinaustralia.gov.au/en/publications-library/technical-report">Revised climate projections</a> released last week by CSIRO and Bureau of Meteorology predict that by 2030, temperatures could be 1.3C above the average for 1986–2005. By 2090, temperatures in Australia could be <a href="https://theconversation.com/climate-projections-show-australia-is-heading-for-a-much-warmer-future-36776">2.8C to 5.1C higher</a> if greenhouse gas emissions remain high, while the frequency of days above 35C and 40C is set to increase.</p>
<p>Since 2001, the number of extreme heat records for daytime maximum temperatures in Australia have outnumbered extreme cool records by almost three to one, and very warm months have <a href="http://www.climatechangeinaustralia.gov.au/en/publications-library/technical-report">increased fivefold over the past 15 years</a>. 2013 and 2014 were Australia’s <a href="https://theconversation.com/whos-been-affected-by-australias-extreme-heat-everyone-36116">hottest and third-hottest years</a>, respectively. </p>
<p>Melbourne’s hottest days are <a href="https://www.climatecouncil.org.au/heatwaves-report">already 2C warmer than in the past</a>. It’s clear that we need to prepare for even hotter summers.</p>
<h2>Heat is lethal for people exercising</h2>
<p>The heat risk from exercise is affected by weather conditions such as temperature, humidity, wind speed and sun exposure, and by other factors including exercise intensity and duration, fitness level, and acclimatisation. Problems arise when the body generates more heat than it can offload to the external environment, causing core temperature to climb. </p>
<p>Almost 80% of energy produced by muscles is heat, and intense physical activity can increase heat generation tenfold. At rest, the body’s normal core temperature is between 36.2C and 37.2C. Physiologists warn that if the body reaches beyond 39.2C, exercise must be stopped and cooling initiated, although body temperatures of <a href="http://www.ncbi.nlm.nih.gov/pubmed/10066720">40C have been recorded in elite athletes</a>. </p>
<p>Acclimatisation and fitness increase heat tolerance, but not indefinitely. Ultimately, hyperthermia results in <a href="http://www.ncbi.nlm.nih.gov/pubmed/10066720">reduced heart performance</a>, low blood pressure, and the risk of <a href="http://www.ncbi.nlm.nih.gov/pubmed/25526658">organ damage and death</a>.</p>
<p>Humans are not built to exercise in hot weather: athletic capacity peaks at air temperatures of just 11C, and <a href="http://www.sciencedirect.com/science/article/pii/S0306456514000540">declines sharply between 21C and 31C</a>. Temperatures beyond 30C bring the risk of hyperthermia and heat stroke. Humidity makes the risk worse by reducing the effectiveness of sweating.</p>
<p>Few sports are without risk in summer heat. Heat stress can even occur in a <a href="http://ksi.uconn.edu/ksi/assets/File/NCCSRecent%20Data%20on%20Heat%20Illness.pdf">hot swimming pool</a>. Endurance sports such as <a href="http://www.smh.com.au/sport/tennis/extreme-heat-proves-too-much-for-canadian-player-frank-dancevic-20140114-30t3y.html">gruelling tennis matches</a>, marathon races and <a href="https://theconversation.com/its-time-for-australia-to-change-its-attitude-to-extreme-heat-22164">cycling tours</a> are especially hazardous, as are football codes and cricket.</p>
<p>Data on heat-related injuries in Australian sport are not collected, but US research reports a <a href="http://ksi.uconn.edu/ksi/assets/File/NCCSRecent%20Data%20on%20Heat%20Illness.pdf">doubling of heat deaths</a> from 1975 (eight deaths) to 2009 (18 deaths), with children of 13 and 15 among the fatalities. </p>
<p>What’s more, playing sport in extreme heat shifts the contest from one of athletic prowess to one of simple heat tolerance. Adopting a gladiatorial approach in which players are expected to play until they drop undermines the core spirit of sport.</p>
<h2>Heated decisions</h2>
<p>Who should make the call when enormous sums of money have been invested? It is very difficult for the players to opt out. With careers and lucrative sponsorships on the line, and world rankings at stake, the pressure to play on is extreme. </p>
<p>Yet the prospect of mass withdrawal initiated by players’ associations is also fraught. There will always be someone ready to take a gamble with their health if there is a whiff of a win by forfeit, so a group walkout by the players is unlikely. </p>
<p>The call must come from the event organisers. They may face conflicting loyalties between financial backers, the players and spectators, yet ultimately, they shoulder a non-negotiable duty of care to protect players’ lives. </p>
<p>High-intensity, hot weather events such as the Australian Open and the Tour Down Under, as well as early starts to the football codes, are potentially lethal. Local-level sports throughout Australian summers are also becoming increasingly risky to health. Further afield, FIFA, world football’s governing body, somehow deemed it appropriate to choose Qatar to host the 2022 World Cup.</p>
<p>The Climate Institute’s call to arms for all sporting codes to acknowledge increasing heat as a serious health threat is timely. As a nation, Australia needs to respond. To genuinely protect players, sports administrators must establish heat guidelines that take account of the physiological dangers of heat, and are also appropriately tailored to the physical intensity and fitness levels within their game. </p>
<p>Monitoring weather conditions and players’ welfare, rescheduling games when required, increasing rest breaks and allowing for rotations of team members, fastidious attention to hydration, providing shade, fans and cool vests – these are all minor adjustments that could save a life. It is also vital to ensure that trained people are on site who are equipped to recognise and treat heat illnesses. </p>
<p>Sometimes medical emergencies are unavoidable in sport. But we shouldn’t be inviting athletes to suffer foreseeable ones such as heat stroke.</p><img src="https://counter.theconversation.com/content/36839/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Liz Hanna receives funding from an NHMRC grant to research impacts of heat on human population, specifically workers, and has previously received other NHMRC project grants to identify health impacts, acclimatisation limits and adaptive options. She is President of the Climate and Health Alliance and Fellow at the Research School of Population Health, National Centre for Epidemiology & Population Health at ANU.</span></em></p>Sport is fundamental to Australia’s society, culture and economy. But how would we cope when the rising heat threatens some of our most beloved pastimes? A new report from the Climate Institute urges sports…Liz Hanna, Director NHMRC Project: Working in the Heat - Health Risks and Adaptation Needs, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/368222015-01-28T19:23:54Z2015-01-28T19:23:54ZCan’t throw, can’t catch: Australian kids are losing that sporting edge<figure><img src="https://images.theconversation.com/files/70257/original/image-20150128-22322-ujfd88.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Australian kids are falling behind their international peers in fundamental movement skills. </span> <span class="attribution"><span class="source">Jason Devaun</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Australians like to think themselves as sporting and fit – a concept reinforced by the success of the country’s elite athletes. But evidence is emerging that Australian kids are falling behind their international peers and are performing worse in skills such as kicking, throwing, catching and jumping than they were 30 years ago.</p>
<p>For some time, researchers have been tracking Australian children’s capacity to run, throw, kick, catch and jump. Collectively, these skills are known as Fundamental Movement Skills.</p>
<p>They are called fundamental because they are required to engage proactively in a high proportion of physical activities and sporting pursuits. Children with these skills are also more also likely to become fit adolescents who continue to <a href="http://nnswlhd.health.nsw.gov.au/health-promotion/files/2014/01/24.pdf">play and enjoy sport</a>.</p>
<h2>Skills in decline</h2>
<p>In Western Australia over the past 30 years 27,000 primary school-aged children have been assessed, both in terms of their skillfulness and fitness. The <a href="http://www.scirp.org/journal/PaperInformation.aspx?PaperID=49336">findings</a> have demonstrated a marked decline in six to 12-year-old children’s general physical fitness and skillfulness.</p>
<p>The biggest decline was observed in six-year-olds, who now perform markedly worse than those assessed in the 1980s in simple tasks such underarm throws, catching and bouncing balls. Using a scaled scoring system whereby 100 points was considered average, the 2014 study found six-year-olds now performed 20 to 30 points less than children three decades ago.</p>
<p>Over the past 13 years in New South Wales around 14,000 children aged nine to 15 <a href="http://www.ncbi.nlm.nih.gov/pubmed/24048319">have been assessed</a> to identify their proficiency in five basic Fundamental Movement Skills.</p>
<p>By the time they left primary school competency was low, with less than 50% being competent at running, jumping, catch kick and overarm throw. Two thirds of the girls and a quarter of the boys had poor scores in the over-arm throw where less than 32% of boys and 8% of girls showed competence.</p>
<p>Similarly poor levels were found in the kick with fewer than 31% of boys and 6% of girls demonstrating mastery. </p>
<h2>Poor comparison with overseas</h2>
<p>Part of my research now is looking at Melbourne children’s mastery of Fundamental Movement Skills compared to our international peers.</p>
<p>More than 400 pupils aged six to ten from four schools were assessed between October 2012 and June 2013 using the same assessment tool as that from studies done to children in the United States.</p>
<p>The latest US study was in 2000 but the findings – when compared to the later Australian data – are still disturbing.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/70223/original/image-20150128-12445-1jyddqb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 1: How Australian children perform at Fundamental Movement Skills compared to their American peers.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Not only are Australian children falling behind their older siblings and parents when at a similar age, as shown by the WA data, but 90% of them are also scoring below average when compared to American children of the same age (see table above).</p>
<p>It’s possible that the Fundamental Movement Skills of US children may also have declined since 2000 although we won’t know until we get any new studies. </p>
<p>But if we look at the Australian data in more depth, we can see Australian children are performing below average in both areas of locomotive and objective control skills compared to the American normative data.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/70226/original/image-20150128-12470-1ul5wzl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 2: Breakdown of the distribution of Melbourne children’s locomotive skills.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Figure 2 (above) shows the distribution of Melbourne children’s performance in locomotive skills which includes running, jumping, hopping, leaping, galloping and sliding.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/70227/original/image-20150128-12458-s7mzmc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 3: Breakdown of distribution of Melbourne children’s object control skills.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Figure 3 (above) shows the distribution of Melbourne children’s performance in object control skills which includes throwing, kicking, striking, underhand rolling, catching and dribbling.</p>
<p>Overall Australian children have very low levels of Fundamental Movement Skills compared to their American peers. Even our most competent children are only performing just above average and none are considered superior compared to American norms.</p>
<h2>Why does this matter?</h2>
<p>It has been found that children who possess good Fundamental Movement Skills have higher levels of physical activity as well as better health-related fitness, but many children are not being given the opportunities to <a href="http://www.qorf.org.au/wp-content/uploads/2014/03/Children_lack_Basic_Movement_Skills.pdf">master these skills</a>.</p>
<p>At present only one in three children, and one in ten young people, meet the current physical activity <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/health-pubhlth-strateg-phys-act-guidelines">guidelines</a> for children of 60 minutes of physical activity every day. Furthermore, fewer than one in three children and young people are meeting the guideline for “no more than two hours of screen-based entertainment” every day.</p>
<p>Given this worrying decline in children’s fundamental movement skills, accompanied by rising levels of <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/health-pubhlth-strateg-active-evidence.htm">sedentary behaviour</a>, it is clear that more needs to be done if Australia is to maintain its reputation as a top sporting nation.</p>
<p>Primary schools can only do so much in the current educational climate.</p>
<p>Physical education has been pushed to the periphery of the school curriculum with the majority of children currently getting well under the recommended two hours of physical education a week.</p>
<p>It is common for classroom teachers to teach physical education but many lack specialists training.</p>
<p>Recent data I have collected from Melbourne primary schools indicate that while 86% of classroom teachers feel confident to take a physical education class, 82% don’t feel confident to make the PE class developmentally appropriate to help children acquire Fundamental Movement Skills.</p>
<h2>Mums and dads to the rescue</h2>
<p>So, at present, the best chance of improving Australian children’s Fundamental Movement Skills lies with parents and care-givers.</p>
<p>They should try to ensure their children are provided ample opportunities to experience different sports so they can practice and develop a broad range of Fundamental Movement Skills.</p>
<p>These opportunities should take the form of both structured sports coaching as well as unstructured play. </p>
<p>Across the globe, Australia is looked up to as a beacon of sporting excellence. Australians are rightly proud of their sporting heritage but the truth is that Australia is in danger of becoming a country of spectators who watch sport rather than participate in it.</p>
<p>To help turn this tide we must equip all children with Fundamental Movement Skills. This will help to ensure that future Australian children are more active and fitter.</p><img src="https://counter.theconversation.com/content/36822/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The data illustrated in figures 1-3 are part of a larger research project that has been funded by Victoria University, Australian Institute of Sport and Gymnastics Australia research grants. </span></em></p>Australians like to think themselves as sporting and fit – a concept reinforced by the success of the country’s elite athletes. But evidence is emerging that Australian kids are falling behind their international…James Rudd, PhD Candidate in Skill Acquisition and Motor Development within the Institute of Sport, Exercise and Active Living (ISEAL) , Victoria UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/363092015-01-15T14:38:10Z2015-01-15T14:38:10ZCap sugar, fat and salt, three hours of exercise a day: Labour’s plan for unhealthy kids<figure><img src="https://images.theconversation.com/files/69122/original/image-20150115-5185-1w7kcfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Have another go.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-93698191/stock-photo-a-young-girl-enjoys-a-sandwich-consisting-of-wholemeal-bread.html?src=pp-same_model-93698170-7&ws=0">Nutrition by Shutterstock</a></span></figcaption></figure><p>The NHS is 67 years old, on its knees and struggling, and its patients are not doing much better. Launching the Labour Party’s new plans for public health today – it’s an election year after all – the shadow health secretary, Andy Burnham, argued that the solution was a combination of patient responsibility and government intervention: a perfect positioning of Labour between personal choice (the Tory favourite) and a nanny state (the domain of Labour’s political roots). </p>
<p>But is this enough? And can this approach not only solve the modern problems of <a href="https://theconversation.com/uk/topics/obesity">obesity</a>, <a href="https://theconversation.com/explainer-what-is-diabetes-11842">diabetes</a> and other behaviour-related conditions but also revitalise the NHS and get it <a href="https://theconversation.com/uk/topics/aande-crisis">off its knees</a>?</p>
<h2>Personal responsibility</h2>
<p>Food does not get eaten unless you put it in your mouth, exercise doesn’t happen if you stay on the sofa and cigarettes have to be bought, unwrapped and lit in order to be smoked. At the end of the day, people behave in unhealthy ways because at some level they choose to. </p>
<p>But people in my profession would be out of a job if that was it. Childhood, <a href="https://theconversation.com/nick-clegg-is-spot-on-over-free-school-meals-18375">learning</a>, beliefs, emotions, <a href="https://theconversation.com/time-to-face-hard-truths-when-it-comes-to-obese-children-15323">parenting</a>, friends, the media, expectations and habit all lead to a sense that there’s not much choice at all and at that moment of thinking “cake now or health in the future”, cake <a href="http://www.amazon.co.uk/The-Good-Parenting-Food-Guide/dp/1118709373">pretty much always wins out</a>. So it is right to call for more personal responsibility, but it would help if someone would take the cake away. </p>
<p>Burnham (along with Luciana Berger, who holds the shadow public health brief) wants to see more intervention and more responsibility – or empowerment as Burnham calls it. Among other things, he wants to see half the population taking up <a href="http://www.nhs.uk/Livewell/fitness/Pages/Whybeactive.aspx">recommended activity levels</a>, and for children in particular two hours of PE a week plus up to a further three hours a day of further activities through breakfast and after-school clubs in extended school hours. It’s a fortuitous focus given the finding of <a href="http://ajcn.nutrition.org/content/early/2015/01/14/ajcn.114.100065.full.pdf+html">a new study from Cambridge researchers</a> that suggests that a lack of exercise is responsible for twice as many deaths as obesity. They argue that just 20 minutes of walking a day could cut the risk of early death by 30%. </p>
<h2>Commercial responsibility</h2>
<p>But if we’re all taking on more responsibility, it is therefore also right for the government to intervene in the activities of the commercial world. Plain packaging should stop smokers being walking adverts for their favourite brands and may <a href="https://theconversation.com/tobacco-companies-are-savvy-about-the-power-of-branding-19528">make the habit less attractive</a> to those who haven’t yet started. </p>
<p>Labour is proposing to cap <a href="https://theconversation.com/the-amount-of-hidden-sugar-in-your-diet-might-shock-you-21867">the levels of sugar</a>, fat and salt sold in children’s food – something that has been notoriously difficult to achieve against a strong food lobby, who have still <a href="https://theconversation.com/food-traffic-lights-are-green-for-go-but-eu-holds-back-more-radical-measures-15403">yet to find voluntary consensus</a> for the traffic light system on food packaging, another focus for Burnham. Any taxes on sugar and fat have been ruled out in favour of “making food healthier in the first place,” Berger said. </p>
<h2>Health dependencies</h2>
<p>Limiting fat, salt and sugar in foods for children would of course help parents make better choices (without even knowing it), and lowering alcohol levels may help with the teenager determined to binge drink. But is that really all that is needed to make a new generation of children the healthiest so far and to save the NHS and save us from these modern problems?</p>
<p>I think that both the demise of the NHS and the rise of both obesity and diabetes reflect a much more fundamental problem beyond either patient responsibility or the nanny state; <a href="https://theconversation.com/aande-is-in-crisis-because-we-all-take-it-for-granted-14458">a culture of health dependency</a>.</p>
<p>Some 200 years ago doctors used leeches, bled their patients and blistered their feet. Today, we have drugs; we’re <a href="https://theconversation.com/record-use-of-antidepressants-just-papers-over-the-cracks-of-modern-life-25959">encouraged to take more medication</a> and that medicine can cure our every ailment. But much as we are told that things are better now, we are not told that far from working for everyone, these drugs <a href="https://theconversation.com/how-science-is-using-the-genetics-of-disease-to-make-drugs-better-30747">only work for some of the people</a>, for some of the time and that even if they do work benefits are often minimal. What about all those <a href="https://theconversation.com/desperate-couples-are-misled-by-only-positive-reports-of-ivf-20163">for whom the treatment didn’t work</a>, who experienced side effects, or even got better on their own? We never hear about that in the media. Instead there’s a pill for every ill and doctors can and should manage our every ailment.</p>
<p>And nor are we told that all drugs have side effects and that there are no drugs for the coughs, colds, fatigue, tummy aches and wind that so often end up at the doctor. As doctor Angus Wallace <a href="http://www.thesundaytimes.co.uk/sto/homeV2/article1503129.ece?shareToken=4b6f891f73e784113857aa6565c90140">recently wrote</a>: people turn to nurses to clean grazes or wounds rather than do it themselves these days.</p>
<p>The emphasis on early detection through screening, symptom detection and health checks is a good thing but symptoms such as bowel changes (colon cancer?), bloatedness (ovarian cancer?) and indigestion (heart disease?) are so commonplace that the doctor’s waiting room fills up, outpatient departments are swamped and our beloved NHS starts to creak. Better health information for patients, and crucially, how to critique it <a href="https://theconversation.com/how-to-avoid-bogus-health-information-on-the-web-36098">may be one way forward</a> for the NHS. </p>
<p>The shadow health secretary wants to save the NHS and make people healthier. But this is more than just about patient responsibility and the nanny state. Until all parts of society start to take responsibility; until we can see the limits to medicine and where we can start to look after ourselves, know when to seek help and when to wait, the NHS is destined to stay on its knees.</p><img src="https://counter.theconversation.com/content/36309/count.gif" alt="The Conversation" width="1" height="1" />
The NHS is 67 years old, on its knees and struggling, and its patients are not doing much better. Launching the Labour Party’s new plans for public health today – it’s an election year after all – the…Jane Ogden, Professor of Health Psychology, University of SurreyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/362362015-01-14T15:00:14Z2015-01-14T15:00:14ZThis Girl Can campaign is all about sex, not sport<p>Sport England has launched <a href="http://www.thisgirlcan.co.uk/">This Girl Can</a> – an edgy promotional campaign that seeks to inspire women to challenge cultural assumptions about femininity that prevent them engaging in sport and exercise. </p>
<p>The short television clips draw upon “real” women’s bodies of difference shapes and sizes as they move, sweat, strain and take pleasure in a range of activities – swimming, kick boxing, football, dance, cycling. The dynamic footage plays to Missy Elliott’s <a href="http://www.youtube.com/watch?v=FPoKiGQzbSQ">Get Ur Freak On</a> and offers different ways of seeing women beyond conventional representations of the static female body as an object of beauty (slim, tanned, delicate). </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/aN7lt0CYwHg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>But there are serious problems here. For a start, why does the campaign undermine this empowering intent by referring to women of all ages as “girls”? </p>
<h2>Throwing like a girl</h2>
<p>Women’s sporting bodies have been subject to a long history of infantilisation and as American philosopher, <a href="http://link.springer.com/article/10.1007%2FBF02331805#page-1">Iris Marion Young</a> said, “throwing like a girl” is a common insult that excludes women from feeling strong, capable and respected. </p>
<p>The marketing staff of Sport England appear not have considered how older women might respond to this less than inspiring form of address. Yes, there are older women depicted in the video, but how would they feel about being called a “girl”? </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/69019/original/image-20150114-3852-tcwdrt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&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">Nope.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/downloading_tips.mhtml?code=&id=838133&size=huge&image_format=jpg&method=download&super_url=http%3A%2F%2Fdownload1.shutterstock.com%2Fgatekeeper%2FW3siZSI6MTQyMTI3MjExNywiYyI6Il9waG90b19zZXNzaW9uX2lkIiwiZGMiOiJpZGxfODM4MTMzIiwicCI6InYxfDE5MzYyMzU5fDgzODEzMyIsImsiOiJwaG90by84MzgxMzMvaHVnZS5qcGciLCJtIjoiMSIsImQiOiJzaHV0dGVyc3RvY2stbWVkaWEifSwiaHYzV3lJRDNWR0ZMZE0weW1ydXdhaGttVFBNIl0%2Fshutterstock_838133.jpg&racksite_id=ny&chosen_subscription=1&license=standard&src=nOL-Nb0Df-4_7uQ9gPFnjw-1-14">High heel image via www.shutterstock.com</a></span>
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</figure>
<p>Many women will not engage with the campaign’s key message about valuing active engagement because of this kind of language. Or were they expecting women to form some kind of identification with feeling “young at heart”? </p>
<p>I am reminded of a marketing colleague at a previous university, who thought the image of a woman’s high-heeled shoe resting on a football was appropriate for a Masters-level sports education course.</p>
<h2>All about ‘real women’?</h2>
<p>By claiming to represent “real” women’s bodies what does the campaign buy into and what does it really challenge? The camera pans across a range of exercising bodies that are not normally privileged on television screens – good. But this campaign is not only still all about women’s flesh, but it tries to sell that as somehow radical or revolutionary. This is seemingly without consideration of how such symbolism might have the opposite effect to what was intended: normalising the slender body, accentuating the desirable and undesirable, what belongs and what doesn’t. </p>
<p>The text that goes along with these images is infused with popular post-feminist appeals to individual empowerment – “I jiggle, therefore I am”. This “can-do girl” is happy “sweating like a pig, feeling like a fox” and embracing being “hot and not bothered”. It seems these bodies, jiggly or otherwise, are just another form of objectification in a popular culture already saturated with sexualised images. </p>
<p>The clips repeat familiar music video formats where highly mobile, athletic female bodies are performing for a male audience. This sits uneasily with our concerns about the <a href="https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/203405/130501_body_confidence_progress_reportv03.pdf">objectification of the female</a> body. <a href="http://www.tandfonline.com/doi/abs/10.1080/02614367.2013.833970">Research</a> has shown that physical activity in the pursuit of desirability is something women eagerly “work on” under the auspices of the male gaze. </p>
<h2>Having it all</h2>
<p>So sweat is now sexy and the moving body is an opportunity for others to reflect back desirability. What is troubling about the hallmark of “have-it-all” femininity is that such identities are not equally available to all or equally desired by all women. </p>
<p>Advertising campaigns like this push a neo-liberal rhetoric of “free choice” to look a certain way, or move in a certain way; yet the choices available are narrow, restrictive and predicated on a narrow version of sexiness. It does not involve a stretch of the imagination to think about how women’s self-reference to “sweating like a pig” through exercise can shift into denigrating terms (“fat pig”) that are used against them if they don’t conform. </p>
<p>It’s disappointing that a campaign to get women more physically active doesn’t focus on <a href="http://www.emeraldinsight.com/doi/abs/10.1108/17582951211229708">how exercise</a> strengthens friendship, reduces the stress of work and care and gives us <a href="http://www.tandfonline.com/doi/abs/10.1080/01490400701756345#.VLZ_Hyesxj4">physical and emotional</a> strength. And we suppose it would be far too much to ask to see a campaign that shows exercise as an opportunity to find an active space outside the cult of body worship and display.</p><img src="https://counter.theconversation.com/content/36236/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simone Fullagar has received funding from the Australian Research Council and Cancer Research UK.</span></em></p><p class="fine-print"><em><span>Jessica Francombe-Webb 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>Sport England has launched This Girl Can – an edgy promotional campaign that seeks to inspire women to challenge cultural assumptions about femininity that prevent them engaging in sport and exercise…Simone Fullagar, Professor, Sport and Physical Cultural Studies, University of BathJessica Francombe-Webb, Lecturer in Sport and Education, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/343432014-11-25T06:26:41Z2014-11-25T06:26:41ZSmoking, drinking and eating: public health should not be all about the individual<figure><img src="https://images.theconversation.com/files/65211/original/image-20141121-1055-9mzsag.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">No butts.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/coreytempleton/6370142363/in/photolist-aGUDoK-cTugid-c5jsUm-dABB5t-iKb8j-5mHQrQ-7oWxPx-6VS48r-h4ZvYU-a6GqSw-6S4qdE-bwNu4J-5mHR3s-61V2QW-9oeFz9-bmvWZ5-555C3q-5QSctJ-ndJTVF-6cnqCw-7RHxcU-6SN2MF-5Cz84W-arBYr9-9mEvvj-5mDCXR-afrKyi-8Uo9uG-pSHbiq-6S3U7-bwNsP9-d68kG1-aeA3EG-eR2eEm-6gqG4w-6g54V2-pes5Jy-5mGdbw-9mBsTt-4ASMLU-8Uk4Xc-nWHtEy-bwNp3q-5WTnfn-cGBC6C-82Uw5F-5w1nkm-bwNurU-bKH8RZ-bKHbxH">Corey Templeton</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Diseases linked to smoking tobacco, a lack of exercise, drinking alcohol and eating unhealthily <a href="http://bit.ly/NgJxo5">are on the rise</a>, even though we have more information than ever before on the risks involved. All indications are that these so-called “lifestyle” diseases are defeating efforts to persuade people to make the right choices; maybe it’s time for a different approach.</p>
<p>We make the case for a <a href="http://www.tandfonline.com/doi/abs/10.1080/09581596.2014.980396#.VGSeu5UqU9g">new style of “practice oriented” public health policy</a>, a move which could amount to a significant change of focus for public health.</p>
<h2>Beyond the individual</h2>
<p>Models of behaviour change that dominate current public health policy, rest on the presumption that individuals are capable of making “better” choices for themselves on the basis of information received, and that their well-being is an outcome of the decisions they make. Contrary to this widely held and popular belief, <a href="http://www.bmj.com/content/342/bmj.d228">research has shown</a> that humans are only partly rational and calculating assessors of information. People often respond automatically and routinely to the demands of their immediate environment.</p>
<p>There are <a href="http://www.instituteofhealthequity.org/projects/fair-society-healthy-lives-the-marmot-review">alternative approaches to health</a> which focus on these “wider determinants” and that highlight the importance of social context, drawing attention to links between social class and patterns of unhealthy behaviour. While these approaches recognise that choices are restricted or determined by social structures, the focus on individual action, albeit constrained, remains.</p>
<p>Neither approach provides much insight into the patterned, routine and habitual ways people live their lives and neither has proved capable of dealing with the problems of so-called “lifestyle” diseases, and the patterns of non-communicable diseases, which follow. </p>
<h2>A focus on social practices</h2>
<p>While behaviour change interventions have had some limited success, the spectre of lifestyle disease is a grim reaper indeed – and will continue its devastating journey unless we can effectively build on new ideas. </p>
<p>Trying to get individuals to adopt healthier lifestyles overlooks the fact that smoking, exercise and eating are fundamentally social practices: they have shared histories, they are shaped by businesses and institutions and they are not simply expressions of personal choice.</p>
<p>The contention that public health can and should take social practices as the central focus of action is informed by a set of ideas which have a long-standing history in the social sciences and which have already been taken up to good effect in other areas, such as environmental change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/65213/original/image-20141121-1052-1jtdtip.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">Diet is not only a matter of personal choice.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/ccaviness/2625223578/in/photolist-4ZYXvu-84oMR2-6xLXtE-gPy47D-5ue2Eo-m6ZEj-69m6Zc-7smQRd-7G2y7a-iqDcL-7smQRy-4Y5emW-f3DKxy-8g1GCe-9xLa59-7smQRs-6SxMQh-7AJ1w7-4dvZ5R-gVNib-8mjxNH-i4uSQH-82YwjC-ag7Jeg-5qMBdY-a1nZC-5e7yb4-Wk7J5-9zyEjN-hNKs9X-7ncwRs-8VgC2U-533guY-4Y5eAu-7MzB5C-6g9ftu-6g9fqj-8kmQQZ-533huU-8bEEdg-GpEDY-extRS8-53MLdd-8cYb8k-69yCZy-5oMBfs-8vrXFD-7W5Vdq-64EXzw-c5jsUm">Clay Caviness</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>This approach draws attention to the fact that our daily lives are made of sometimes competing, sometimes mutually reinforcing complexes of social practice. </p>
<p>For example, having a takeaway on a Friday night and watching the TV are two practices that might support each other, whereas going to the gym and staying in to share a bottle of wine are (potentially) rival pursuits, competing with each other for time in the daily routine.</p>
<h2>Opportunities for intervention</h2>
<p>Some measures in this vein have already begun to take effect. For example, the smoking ban in public places has helped break associations between going out for a meal and smoking. It did so by changing what smoking involves and consequently changing the reality.</p>
<p>Despite the promise and the potential, switching the core planks of public health policy away from individual choice and toward social practice is likely to be an uphill struggle. </p>
<p>This is not because the ideas are hard to understand or because they are difficult to mobilise, but because current approaches reproduce a model of rights and responsibilities associated with individualism and self-management. If public health policy is to stand a chance of confronting, let alone addressing the scourge of non-communicable disease, it will have to find the courage to break away from this mould. </p>
<p><em>This article was co-authored with Chris Carmona and Mike Kelly from the <a href="http://www.nice.org.uk/">National Institute for Health and Clinical Excellence</a>.</em></p><img src="https://counter.theconversation.com/content/34343/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span> Elizabeth Shove and the DEMAND Centre receive funding from the RCUK Energy Programme and EDF as part of the R&D ECLEER Programme. </span></em></p><p class="fine-print"><em><span>Stanley Blue 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>Diseases linked to smoking tobacco, a lack of exercise, drinking alcohol and eating unhealthily are on the rise, even though we have more information than ever before on the risks involved. All indications…Stanley Blue, Lecturer, University of ManchesterElizabeth Shove, Professor, Sociology, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/323132014-10-31T09:44:21Z2014-10-31T09:44:21ZHow low can marathon times go?<p>This fall <a href="http://olympictalk.nbcsports.com/2014/09/28/dennis-kimetto-berlin-marathon-world-record/">Dennis Kimetto</a> set a new world record in the marathon, clocking 2:02:57 at Berlin. He is the first man to run those 26.2 miles in under 2:03 and his time sparked speculation about when the two-hour barrier for the marathon might fall. Just how fast can a human being run in an endurance race like this?</p>
<h2>The marathon’s start</h2>
<p>The marathon is based on the legend of <a href="http://www.marathonguide.com/history/olympicmarathons/prologue.cfm">Philippides</a>, a messenger who, the story goes, ran about 25 miles from the battlefield at Marathon to Athens in 490 BC. He announced a great Greek victory over the Persians and then promptly died. No word on his official time.</p>
<p>Cut ahead to 1896 and the inaugural modern Olympic games, held in Greece. The marathon as a race was cooked up as a run from Marathon to Athens. The distance increased by a little over a mile to the current 26.2 miles (42.2 km) at the London Olympics to accommodate a start at Windsor Castle, and that distance was adopted as the standard in the early 1920s.</p>
<h2>Things got faster fast!</h2>
<p>The <a href="http://en.wikipedia.org/wiki/Marathon_world_record_progression">progression of the men’s record times</a> breaks into three distinct eras.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=345&fit=crop&dpr=1 600w, https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=345&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=345&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=434&fit=crop&dpr=1 754w, https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=434&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/62891/original/6qyn43v3-1414425227.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=434&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Men’s World Record Marathon Times.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The first lasts from 1908 until the middle 1950s. Over this time the runners started training progressively harder.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=644&fit=crop&dpr=1 754w, https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=644&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/62899/original/c4mzzwq2-1414428263.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=644&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Abebe Bikila winning the 1960 Olympic marathon – barefoot.</span>
</figcaption>
</figure>
<p>By the 1950s, top competitors were running 100 miles or more per week; most were from the developed world. In 1960, <a href="http://www.olympic.org/abebe-bikila">Abebe Bikila</a> from Ethiopia won the marathon at the Rome Olympics. His victory was the start of the globalization of the marathon in general and the ultimate East African dominance in distance running we see today. </p>
<p>The record then stagnated until the early 1980s. That’s when the professional era really took off and big races with big prize money became well-established.</p>
<h2>What does it take to go fast?</h2>
<p>Physiology research reveals three basic determinants of who runs fast. First, an elite marathoner must be able to consume large amounts of oxygen during maximum exercise, about 20-25 times the resting value. That is <a href="http://jp.physoc.org/content/586/1/35.full">twice the capacity</a> of an untrained healthy young male. A runner must have a big, strong heart that can pump blood to the muscles which use the oxygen.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/63251/original/7z38h8wv-1414631394.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">Measuring a runner’s oxygen capacity in the lab.</span>
<span class="attribution"><span class="source">Christopher Johnson</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Second, he must be able to sustain about 80% of his maximum heart rate – usually about 160 beats per minute – for several hours without a buildup of lactic acid in his muscles. At the same time, he doesn’t want to deplete his body’s stores of sugar and hit the wall.</p>
<p>Third, he must be mechanically efficient at turning energy into power. Physiologists talk about <a href="http://www.ncbi.nlm.nih.gov/pubmed/15233599">running economy</a>. A top marathoner must be able to run fast without consuming too much oxygen; this efficiency is due in part to how well a runner uses the muscles and tendons in his legs as biological springs that store energy with each foot strike. </p>
<p>All these same factors apply to the shes as well the hes, but on average elite women can consume only about 90% as much oxygen as men at maximum. Women have more body fat and their blood contains less of the oxygen-carrying protein hemoglobin. Essentially they have smaller engines that generate proportionally a bit less horsepower. This explains why the world records for women in distance running are about <a href="http://www.ncbi.nlm.nih.gov/pubmed/20881885">10-12% slower</a> than men. </p>
<p>At the moment, East African runners seem to always wind up atop the podium. Their physiological numbers aren’t the best ever measured in the lab. But to their advantage, they tend to be of smaller stature, have been physically active from childhood, live at high altitude, and train incredibly hard.</p>
<h2>How fast is possible?</h2>
<p>Back in 1991, I created a <a href="http://jap.physiology.org/content/jap/70/2/683.full.pdf">model of marathon performance</a>. When I asked what would happen if the same athlete had optimal values for the three key variables associated with distance running success, the estimated time was just under 1:58:00.</p>
<p>I <a href="http://www.ncbi.nlm.nih.gov/pubmed/20689089">revisited</a> the model in 2011 with my colleagues Alejandro Lucia and Jonatan Ruiz and concluded that if current trends continued, 2 hours would fall sometime between 2025 and the late 2030s. What seemed inconceivable in 1991 is getting closer by the year. Starting in <a href="http://en.wikipedia.org/wiki/Marathon_world_record_progression">2007 with Haile Gebrselassie’s</a> 2:04:26, the record has been broken five times, and fallen almost 90 seconds, suggesting our projections are on track. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/63061/original/kqhzqnbv-1414525743.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">More and more marathoners, more chances for new records.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-123388867.html">Runners image by ostill via www.shutterstock.com</a></span>
</figcaption>
</figure>
<h2>Not so fast?</h2>
<p>Many elite runners have marathon bests about 4.6 or 4.7 times their fastest 10k times – a marathon being about 4.2 times longer than a 10k. Using this rule of thumb the <a href="http://en.wikipedia.org/wiki/10,000_metres_world_record_progression">current world record for the 10k</a> of 26:17:53 works out to a predicted marathon time somewhere between just under 2:01 and about 2:03:25. Similar values emerge using various <a href="http://www.hillrunner.com/calculators/raceconversion.php">race conversion calculators</a> and point tables. This suggests the current marathon world record has room for improvement. </p>
<p>Of course, going from just under 2:03 to just under 2:00 would be an improvement of 2.5% and such big jumps in distance running records have not happened since the middle 1960s. When assessed in the lab, elite runners then had just about the same data as elite runners do now. It’s not the case that we’re seeing runners who are drastically better equipped than their predecessors. But there are a few things that could help these elite runners go just that much faster….</p>
<h2>2:02 or bust!</h2>
<p>I expect to see a marathon time under 2:02 soon and when we do, that’s when the fun will begin. To get there faster and maybe even to 2:01, I suggest three things:</p>
<ul>
<li><p>A prize money scheme that would motivate the best runners to all show up at the same race, hit fast intermediate times and work together for as long as possible. For example, separate pools of money could be split by all athletes under specific times at the half marathon, 30k, 35k, and 40k marks. Marathons are not golf and the top professionals can only do 1 or 2 races per year so they have to look for big paydays when they can get them.</p></li>
<li><p>Develop a flat 5-8km loop with a <a href="http://biomech.media.mit.edu/wp-content/uploads/sites/3/2013/04/Energetics-and-mechanics-of-human-running-on-surfaces-of-different-stiffnesses.pdf">fast surface</a> and have an elites-only race.</p></li>
<li><p>Run the race on a <a href="http://www.runnersworld.com/races/whats-the-optimal-temperature-for-marathons">cool day</a> at dusk. There is anecdotal evidence that people run a bit faster in the afternoon or evening than in the morning.</p></li>
</ul>
<p>There’s likely an <a href="http://jeb.biologists.org/content/211/24/3836.full">absolute minimum time</a> in which a human being can run a marathon – but we haven’t seen it yet!</p><img src="https://counter.theconversation.com/content/32313/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Joyner 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>This fall Dennis Kimetto set a new world record in the marathon, clocking 2:02:57 at Berlin. He is the first man to run those 26.2 miles in under 2:03 and his time sparked speculation about when the two-hour…Michael Joyner, Professor of Anesthesiology, Mayo ClinicLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/195252014-08-11T05:59:26Z2014-08-11T05:59:26ZHealth Check: tips on eating to recover after exercise<figure><img src="https://images.theconversation.com/files/56126/original/x2zrr7c7-1407725582.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Re-fuelling after exercise is important for maintaining adequate energy stores for beneficial changes in your muscles (training adaption).</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/katalin89/14643417485">Szabó Varga Katalin/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Sports performance was once thought to be enhanced by <a href="http://jn.nutrition.org/content/127/5/874S.long">practices such as drinking cognac</a> before an Olympic marathon run. Thankfully, today’s nutrition strategies are more scientific and properly researched.</p>
<p>We now know quite a lot about when and what to eat before, during, and after exercise for better performance. Of course, what you eat at all these points plays a role but what you eat to recover after exercise (<a href="http://www.ncbi.nlm.nih.gov/pubmed/21116024">recovery nutrition</a>) supports the body’s physiological adaptation to the demands of training and competition. And it prepares the body for the next event. </p>
<p>It replenishes fuel stores in muscles and the liver, minimises muscle loss and encourages muscle growth and repair, minimises fatigue and injury, and supports immune function. Replenishing fluid is also vital but outside the scope of this article.</p>
<p>Re-fuelling after exercise is important for maintaining adequate energy stores for beneficial changes in your muscles (training adaption). But it shouldn’t be in excess of the metabolic demands of what you’ve done if you want to maintain appropriate weight, body composition and <a href="http://www.ncbi.nlm.nih.gov/pubmed/20181066">support performance goals</a>. </p>
<h2>Getting carbs right</h2>
<p>Training and competition require energy, and the energy muscles use is supplied by a mix of fuels in different proportions depending on the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2278845/?tool=pmcentrez&report=abstract">intensity</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/8214047">duration</a> of exercise. In general terms, carbohydrates are the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2278845/?tool=pmcentrez&report=abstract">primary fuel source</a> as exercise intensity increases. </p>
<p>The type of carbohydrate used by the body as <a href="http://www.ncbi.nlm.nih.gov/pubmed/21660838">fuel for exercise</a> is glucose. Consuming carbohydrates before and during prolonged exercise (such as a marathon run) will replenish glucose, delay the onset of fatigue, and allow you to compete for a longer period of time.</p>
<p>Glucose is stored in the muscles and liver as glycogen, and research shows <a href="http://www.ncbi.nlm.nih.gov/pubmed/15618337">low muscle glycogen</a> can impair performance. Depending on when the last carbohydrate meal was consumed, <a href="http://www.ncbi.nlm.nih.gov/pubmed/21660838">glycogen reserves can be depleted</a> after about 60 to 90 minutes of intense exercise. </p>
<p>Planning for glycogen replacement requires adjusting for variations in exercise intensity and duration, the amount of muscle you have, your training goals, and dietary intake at other times, including before and during events. So total carbohydrate targets can vary considerably. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/56130/original/4496h5rg-1407726150.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">Consuming carbohydrates before and during prolonged exercise (such as a marathon run) will replenish glucose, delay the onset of fatigue, and allow you to compete for a longer period of time.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/omcoc/3228070371">ed_needs_a_bicycle/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p><a href="http://www.sportsdietitians.com.au/resources/upload/120628%20Recovery_SD%20version.pdf">Post-exercise carbohydrate recommendations</a> for athletes generally suggest consuming about 1.2 grams of carbohydrate for each kilogram of body weight within an hour of completion, and each hour for four hours after activity. This should be followed by regular carbohydrate intake appropriate to meet daily requirements. </p>
<h2>Replacing muscle protein</h2>
<p>But there are also other things you’re going to need to recover properly. What you generally eat and the type of exercise you do can both affect the <a href="http://www.ncbi.nlm.nih.gov/pubmed/23899756">synthesis of protein in your muscles</a>. </p>
<p>Physical training is a stimulus for muscle growth and adaptation. Hard-working muscles come under stress during physical activity, and the body’s limited reserves of amino acids (what proteins are made from) become rapidly depleted. </p>
<p>Consuming protein or amino acids after exercise can <a href="http://www.ncbi.nlm.nih.gov/pubmed/23765352">reduce muscle breakdown</a> and encourage new tissue growth. But here again, individual responses and requirements can vary quite a lot. </p>
<p>The type and amount of your protein intake both play a role in muscle reconditioning after exercise, with some evidence suggesting that dairy proteins, such as <a href="http://www.ncbi.nlm.nih.gov/pubmed/23765352">whey protein, may offer advantages</a> over other sources. </p>
<p>But studies are not consistent about ideal timing. Some suggest consumption before exercise while others recommend consumption <a href="http://www.ncbi.nlm.nih.gov/pubmed/23899756">within 24 hours</a> of completion offers most benefit. </p>
<p>Generally speaking, <a href="http://www.ncbi.nlm.nih.gov/pubmed/23899756">consuming 20 to 25 grams of quality protein</a> as soon as possible after exercise is recommended for building muscle and help reconditioning. Another recommendation is around <a href="http://www.ncbi.nlm.nih.gov/pubmed/23899756">0.25 to 0.3 grams protein per kilogram of body mass</a>.</p>
<h2>Best foods</h2>
<p>It follows that foods containing both carbohydrates and protein are generally recommended as being best for recovery. And there are other advantages – consuming protein with carbohydrates may improve glycogen replenishment and <a href="http://www.ncbi.nlm.nih.gov/pubmed/21116024">reduce muscle breakdown</a>. The optimal carbohydrate to protein ratio for glycogen replenishment is <a href="http://www.ncbi.nlm.nih.gov/pubmed/20181066">three to one</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/56135/original/cygjty4y-1407727930.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">
<figcaption>
<span class="caption">Consuming protein after exercise can reduce muscle breakdown and encourage new tissue growth.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/isaachsieh/2438339342">Isaac Hsieh/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>In general, moderate to high glycaemic index, low-fibre carbohydrate sources are preferable because they’re digested and absorbed rapidly. And good quality plant- or animal-derived protein foods are better because they contain essential amino acids.</p>
<p>The <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/health-pubhlth-strateg-phys-act-guidelines/$File/Brochures_PAG_Adults18-64yrs.PDF">average person exercising</a> at low to moderate intensities for around 30 minutes a day on most days of the week, should <a href="http://www.eatforhealth.gov.au/guidelines">follow general dietary guidelines</a> to meet their energy and nutritional needs. </p>
<p>But it’s worthwhile trying to adjust mealtimes to coincide with recommended post-workout time (30 to 90 minutes) for eating. Adding an extra recovery meal, or a high-sugar sports drink, will merely increase your risk of consuming more than you need.</p>
<p>Specialised nutrition plans are particularly <a href="http://www.ncbi.nlm.nih.gov/pubmed/20181066">useful for highly active and trained people</a> who engage in moderate to high intensity activity for between two and six hours every day most days of the week. </p>
<p>Energy requirements increase at this level and carefully planned nutrient intake and timing will support performance while minimising fatigue and injury. </p>
<p>Here are <a href="http://www.ausport.gov.au/ais/nutrition/factsheets/competition_and_training/recovery_nutrition">a few examples of foods</a> that may support an athlete’s recovery eating plan, containing protein, as well as approximately 50 grams of carbohydrate:</p>
<ul>
<li>two cups of breakfast cereal with milk,</li>
<li>two slices of toast with 220 grams baked beans,</li>
<li>a large baked potato with cottage cheese plus glass of milk,</li>
<li>200 grams of fruit yoghurt with 300 grams of fruit, or</li>
<li>a bread roll with lean meat or cheese and a large piece of fruit</li>
</ul>
<p>The most important thing to remember is that there is no one size that fits all. Individual nutrition plans are best developed with the help of qualified sports nutrition experts and may involve some trial and error for the best outcome.</p><img src="https://counter.theconversation.com/content/19525/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nigel Stepto has received funding from National Health and Medical Research Council and Australian Institute of Sport (Australian Sports Commission). He is affiliated with Exercise and Sports Science Australia (ESSA).</span></em></p><p class="fine-print"><em><span>Kristina Vingrys (Nelson), Lily Stojanovska, and Michael Mathai 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>Sports performance was once thought to be enhanced by practices such as drinking cognac before an Olympic marathon run. Thankfully, today’s nutrition strategies are more scientific and properly researched…Kristina Vingrys (Nelson), PhD Candidate and Nutritionist, Victoria UniversityLily Stojanovska, Professor and Acting Director Centre for Chronic Disease Prevention and Management, Victoria UniversityMichael Mathai, Associate Professor, Victoria UniversityNigel Stepto, Associate Professor in Exercise Physiology and Clinical Exercise Science Research Program Leader in Institute of Sport Exercise and Active Living (ISEAL), Victoria UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/293902014-07-22T19:59:01Z2014-07-22T19:59:01ZSick of exercise? Here’s how training can lower immunity<figure><img src="https://images.theconversation.com/files/54397/original/j58cp2h4-1405922986.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">On your mark, get set ... ah-choo!</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/placbo/2826724783">placbo/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Exercise is good for you – we hear it all the time. <a href="http://www.runnersworld.com/health/sitting-is-the-new-smoking-even-for-runners">Sitting is the new smoking</a>. Exercise reduces the <a href="http://www.ncbi.nlm.nih.gov/pubmed/20159820">risk of cancer</a>, improves your <a href="http://www.ncbi.nlm.nih.gov/pubmed/24948672">memory</a> and makes you <a href="http://www.ncbi.nlm.nih.gov/pubmed/24982639">happier</a>.</p>
<p>But does exercise have a sinister side that we’re not aware of? There is a common idea held by athletes that intense training for an endurance event, such as running a marathon, will leave one more susceptible to illnesses. </p>
<p>Exercise, especially prolonged or intense exercise, <em>does</em> impact your <a href="https://theconversation.com/explainer-what-is-the-immune-system-19240">immune system</a>. The immune system protects us from disease, so upsetting the balance of these essential cells and molecules could potentially leave us susceptible to increased risk of disease.</p>
<p>Neutrophils are the most abundant immune cells in our blood and ingest invading microbes. Following exercise, these cells <a href="http://www.ncbi.nlm.nih.gov/pubmed/12690938">increase</a> in number in two waves: immediately after and several hours following exercise. But while the number of neutrophils increases, their ability to ingest, and therefore destroy, microbes actually <em>decreases</em>.</p>
<p>Numbers of natural killer cells, that help kill virally infected cells, have been shown to <a href="http://www.ncbi.nlm.nih.gov/pubmed/22990626">decrease</a> during intense training periods in elite swimmers.</p>
<h2>The first line of defence</h2>
<p>Secretory IgA (<a href="http://www.nature.com/mi/journal/v4/n6/full/mi201141a.html">sIgA</a>) is an important protein that plays a major role in protecting us from respiratory infections. </p>
<p>It is found in sites throughout the body such as the intestines, the lungs and importantly in saliva. sIgA binds to bacteria and viruses as they enter the body and stops them from entering our cells.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/21385218">Studies</a> have shown that when the level of sIgA in saliva is high the risk of upper respiratory tract infections (URTIs) is low, and people with <a href="http://www.ncbi.nlm.nih.gov/pubmed/23389234">sIgA deficiency</a> suffer from URTIs more than the general population.</p>
<p>A <a href="http://www.ncbi.nlm.nih.gov/pubmed/16596116">study</a> of athletes who completed the Western States 100-mile (161km) Endurance Run found that overall salivary sIgA secretion dropped by almost half, and, interestingly, those that developed an URTI had the greatest decrease in sIgA levels in the saliva. </p>
<p>Other <a href="http://www.ncbi.nlm.nih.gov/pubmed/22516911">studies</a> of athletes also showed a decrease in sIgA levels following prolonged or high-intensity exercise, but <a href="http://www.ncbi.nlm.nih.gov/pubmed/20051733">not all studies</a> agree.</p>
<h2>Why do these changes occur?</h2>
<p>The cause of changes to the immune system following intense exercise is unclear, although numerous factors probably play a role including hormonal and psychological factors. </p>
<p>Some studies suggest that decreased salivary IgA may be due to an <a href="http://www.ncbi.nlm.nih.gov/pubmed/20631639">increase in salivary cortisol</a>. Those immune alterations may also be in part related to <a href="http://www.ncbi.nlm.nih.gov/pubmed/15560351">psychological stress</a> induced by training. </p>
<p>Supporting this, in one <a href="http://www.ncbi.nlm.nih.gov/pubmed/18821985">study</a>, stress from competing in an international championship was associated with reduction of salivary IgA in both athletes and staff members.</p>
<h2>Do these changes lead to illness?</h2>
<p>Do changes to neutrophils and sIgA, as well as other changes to immune cells and molecules, result in an increased risk of infections? </p>
<p>The science is unclear, especially given that changes seem to be transient, but the “<a href="http://www.ncbi.nlm.nih.gov/pubmed/20839496">open window</a>” theory suggests that these short-term changes may result in increased susceptibility to infection.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/54407/original/5zbdfjyb-1405925456.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&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"><a class="source" href="http://www.flickr.com/photos/mr172/8241245560">Michael/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>The “open window” hypothesis suggests that for a short period of time following exercise the athlete is more susceptible to any microbes they are exposed to during this time. While this proves an interesting idea, there have been no studies to support it.</p>
<h2>Avoiding illness</h2>
<p>Some authors suggest that <a href="http://www.ncbi.nlm.nih.gov/pubmed/19223675">vitamin C supplementation</a> might contribute to decrease in post-exercise salivary cortisol. Other studies show that a <a href="http://www.ncbi.nlm.nih.gov/pubmed/16320174">high carbohydrate diet</a>, or a diet high in <a href="http://www.ncbi.nlm.nih.gov/pubmed/23927572">beta-glucans</a> (found in oats, barley and mushrooms) may have some benefits for salivary cortisol and/or IgA levels and hence for post-exercise URTI occurrence. </p>
<p>So far, amongst all the nutrients tested in research, there is no expert recommendation on diet, but a high carbohydrate diet appears to be the <a href="http://www.ncbi.nlm.nih.gov/pubmed/23112908">best option</a>.</p>
<p>The best ways to avoid illness during the training period and immediately before and after competition is to stay away from infectious people (always good advice!), wash hands regularly particularly before eating and avoiding, as much as possible, touching your face. A well-balanced diet, potentially high in carbohydrates, is recommended.</p>
<p>Moderate exercise is associated with positive effects in many areas of life and may be anti-inflammatory. More intense exercise may lead to changes in the immune system, but these seem to be short-lived and may be of little importance in overall health. So don’t let these changes put you off entering your first, or next, race!</p><img src="https://counter.theconversation.com/content/29390/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>Exercise is good for you – we hear it all the time. Sitting is the new smoking. Exercise reduces the risk of cancer, improves your memory and makes you happier. But does exercise have a sinister side that…Kim Murphy, Immunology researcher, Monash UniversityFabien B. Vincent, Rheumatologist; PhD student, Department of Immunology, Faculty of Medicine, Nursing and Health Sciences, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/284282014-06-27T05:11:03Z2014-06-27T05:11:03ZWhy an autumn birthday could win you first place on sports day<figure><img src="https://images.theconversation.com/files/52243/original/dssc66yf-1403701095.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Born in the right month.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/lukebosman/188283893/sizes/l">longwayround</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>The playing field may not be level for school sports due to physical differences between children born in different months.</p>
<p>Our <a href="http://repository.essex.ac.uk/9686/">research measured 8,550 children’s stamina</a>, muscle strength and power. Those born in the autumn had a clear physical advantage over children born at other times of the year.</p>
<p>Unfortunately, long ago in England, we adopted a September 1 cut-off for school entry. This was historically to allow children to help with the harvest. Now, it means the oldest children in each year are also those who benefit from summer vitamin D exposure – a double advantage. If we moved the cut-off to April fool’s day the smaller and less fit children would be the oldest in their school-year which might cancel out the autumn advantage.</p>
<p>The tests we used in our research are standard indicators of physical performance. We tested children during PE lessons, following a standardised procedure, but then we converted them to age-related percentile scores using a commercially <a href="http://www.FitmediaFitness.co.uk">available testing system</a>. </p>
<p>Stamina was measured using the 20m shuttle-run (bleep-test) in which the children ran as the speed gets faster-and-faster until they choose to stop. Global data from this test show us children’s fitness levels are declining about <a href="http://www.ncbi.nlm.nih.gov/pubmed/17387251">4% per decade</a> – but we found the rate was closer to <a href="http://news.bbc.co.uk/1/hi/health/8425161.stm">10% in English children</a>. </p>
<p>We also measured children’s strength using an handgrip dynamometer and their explosive lower body power via a timing “mat” which measures how long they are off the ground, also known as their flight time. Then, with some maths involving mass and gravity we calculated how powerful they are.</p>
<h2>September is the best month</h2>
<p>Media coverage of our research has omitted the important point that we controlled for the age of participants. This is important as it allows us to compare children of exactly the same age (we subtracted the date-of-test from date-of-birth to be accurate to the day). This means we did not look at the “relative age” effect (being older in your school year), and we didn’t compare by school year, only by age.</p>
<p>Previous research we <a href="http://repository.essex.ac.uk/7279/">published on relative age last year</a> showed a small advantage for autumn and winter-born children’s fitness level depending on when they were born, but the effect was nearly twice as big as our study on the month of birth. If we were studying the relative age effect, children born in September would be the fittest.</p>
<p>Other researchers have found that autumn-born babies are longer (crown-rump length), heavier and more <a href="http://www.ncbi.nlm.nih.gov/pubmed/16352684">muscular at birth than summer babies</a>. They have put this down to greater vitamin D exposure during the third trimester of the pregnancy. It is in this third trimester that the foetus develops much of its bone mass and musculature. This is why October babies whose mums get sunshine in July, August and September are bigger – and possibly why they go on to be fitter and stronger.</p>
<p>Finding ways to mitigate the disadvantage isn’t just important for sports. The chief medical officer, <a href="http://news.bbc.co.uk/1/hi/health/8568111.stm">Liam Donaldson has proposed national fitness assessments</a> for health monitoring purposes. I endorse this, but it has to be done properly, sensitively and accounting for relative age. </p>
<p>We used a health-related cut-offs for our tests to identify children with “clinically” low fitness. April-born children were twice as likely to have clinically low muscle strength and were 50% more likely to have low fitness. Such differences should be accounted for in any testing carried out in schools.</p>
<h2>Ways to level the playing field</h2>
<p>It’s unlikely the government will switch the school entry date based on differences in physical performance. However, in New Zealand (where the effect is reversed) they put weight limits in schools sports to take away the simple advantage of being the biggest. In Scotland, a small number of players in (for example) Year 8 are allowed to play for Year 7 teams. </p>
<p>More complex ideas could involve limiting the number of players in a team to 50% born between September and March and 50% born between April to August. Schools could even have two teams per year based on six-monthly age grouping (the under 12’s and the under 11 and a halves). </p>
<p>Of course this would mean some of the best and biggest children not being picked, but if sports is about talent development and potential that should be ok. That said, I would find it hard not to field the team most likely to win and imagine most teacher and coaches would, and parents of November born superstars sitting on the side-line might also query this.</p>
<p>One unexpected pattern in the data was that children born in October and November came from families which were, on average slightly richer than those of children born in other months. This might be that some better-off families are actually planning their family birth dates to give their children a better start by being born early in the school year. But that’s just an idea and we can’t prove it!</p><img src="https://counter.theconversation.com/content/28428/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gavin Sandercoc owns shares in FitmediaFitness.</span></em></p>The playing field may not be level for school sports due to physical differences between children born in different months. Our research measured 8,550 children’s stamina, muscle strength and power. Those…Gavin Sandercock, Reader in Sports Science (Clinical Physiology) , University of EssexLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/263262014-05-07T00:33:41Z2014-05-07T00:33:41ZVIDEO: The benefits of high-intensity workouts<figure><img src="https://images.theconversation.com/files/67425/original/image-20141217-14150-1s6nhu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">High intensity workouts</span> </figcaption></figure><figure>
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<p><br></p>
<p>High intensity workouts (HIT) are the number-one fitness trend worldwide, comprising short intervals of exercise at a very high intensity, interspersed with periods of recovery or rest. And despite its lower energy and time commitment, HIT workouts are actually quite good at improving our aerobic fitness. </p>
<p>So how do they stack up against more traditional exercise regimes? We find out in this week’s episode of TCTV.</p>
<p>This video is a co-production between <a href="http://www.sbs.com.au/news/">SBS World News</a> and The Conversation.</p>
<p><strong>See also:</strong><br>
<a href="https://theconversation.com/health-check-high-intensity-micro-workouts-vs-traditional-regimes-18617">Health Check: high-intensity micro workouts vs traditional regimes</a><br>
<a href="https://theconversation.com/video-how-laser-tattoo-removal-works-25857">VIDEO: How laser tattoo removal works</a><br>
<a href="https://theconversation.com/video-solving-the-worlds-toilet-shortage-25738">VIDEO: Solving the world’s toilet shortage</a><br>
<a href="https://theconversation.com/video-were-the-first-artists-women-25590">VIDEO: Were the first artists women?</a></p><img src="https://counter.theconversation.com/content/26326/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nigel Stepto receives funding from NHMRC. He is affiliated with and accredited by Exercise and Sport Science Australia.</span></em></p><p class="fine-print"><em><span>Chris Shaw has received funding from BUPA Foundation UK and the Insulin Dependent Diabetes Trust. He is a member of the PCOS alliance, European College of Sports Science and the American Physiological Society. He is also an accredited Exercise Physiologist with Exercise & Sports Science Australia.</span></em></p>High intensity workouts (HIT) are the number-one fitness trend worldwide, comprising short intervals of exercise at a very high intensity, interspersed with periods of recovery or rest. And despite its…Nigel Stepto, Associate Professor in Exercise Physiology, Victoria UniversityChris Shaw, Research Fellow, Institute of Sport, Exercise and Active Living, Victoria UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/242762014-04-10T04:33:20Z2014-04-10T04:33:20ZBrute force: reducing the impact of rugby collisions<p>The legendary American Football coach Vince Lombardi <a href="http://www.quotes.net/quote/1364">once said</a> “Football is not a contact sport, it’s a collision sport – dancing is a contact sport”. This is equally applicable to the various codes of rugby, which captivate audiences with player-on-player impacts. </p>
<p>And from time to time, a tackle gone wrong results in serious injury, as we saw when Newcastle forward Alex McKinnon broke his spine after <a href="http://www.abc.net.au/news/2014-04-03/mclean27s-suspension-ranks-among-heftiest-sideline-stints/5364730">landing on his head</a>.</p>
<p>So, how big are the collisions in rugby? And how can we reduce the risk of injury from that force? </p>
<p>In rugby union, there are multiple forms of collisions – in the tackle, joining <a href="http://news.bbc.co.uk/sportacademy/hi/sa/rugby_union/rules/newsid_3434000/3434821.stm">rucks and mauls</a> (which can end up looking like a pile-up of bodies), <a href="http://en.wikipedia.org/wiki/Scrum_(rugby)">scrum engagement</a> (where players form rows and literally go head to head with their opponents), or even with the ground. </p>
<p>In <a href="http://www.ncbi.nlm.nih.gov/pubmed/17474043">an analysis</a> of Bledisloe Cup rugby matches between Australia and New Zealand in 2004, researchers counted an average of nearly 500 collisions in a game: 26 scrums, 200 rucks and mauls, and 270 tackles.</p>
<p>In rugby league, the scrums are fewer and less contested, and rucks and mauls non-existent. Tackles, while less frequent, are no less fierce. In 2011, <a href="http://www.ncbi.nlm.nih.gov/pubmed/21689986">Sydney researchers recorded</a> on average, 111 tackles per game among professional players. </p>
<p>Inadvertent collisions can be added to the number of impact events in a game, along with all the collisions in training that often go unreported.</p>
<p>The force involved in a player-on-player clash is related to the speed immediately before and after the collision, the mass (weight) of the bodies involved, the duration of impact and where on the body the impact occurred (soft abdomen or rigid shoulder). </p>
<p>But measuring the impact mass of the player(s) involved in the collision is not as simple as it appears. It’s not just the body weight of the player – it can be a lot less, as arms and legs may be free to swing during the moment of impact and therefore don’t contribute to the impacting mass calculations. </p>
<p>Also, whether the impact was direct or oblique will affect the impact force. </p>
<p>To get around this, several research teams have attempted to measure tackle impacts using instrumented training sleds, tackle bags and, more recently, instrumented shoulder pads. Using shoulder pads, Australian researchers <a href="http://www.sciencedirect.com/science/article/pii/S144024401100106X">reported</a> rugby shoulder tackles had an average force of 1997 newtons (1997N), the equivalent of 206kg. </p>
<p>Researchers from the United States have reported much larger forces among American Football players. The athletes <a href="http://ajs.sagepub.com/content/25/3/317.short">hit</a> an instrumented tackle training sled at 3013N, or almost one third of a tonne; while <a href="http://www.sciencedirect.com/science/article/pii/S1440244011001228">the force</a> of an instrumented helmet-on-helmet impact during games was as around 7191N, or nearly three-quarters of a tonne.</p>
<p>This shows the cushioning effect of impacting softer body parts in unprotected rugby players compared to padded and helmeted American Football players. It increases the time over which the collision takes place and lessens the impact of the force.</p>
<p>The stresses experienced by front-row forwards during rugby union scrummaging are also substantial. An international research team recorded forward-directed forces of up to 7982N (more than three-quarters of a tonne), as players packed down against an instrumented scrum machine. The hooker alone (the player at the centre fo the scrum) <a href="http://bjsm.bmj.com/content/early/2014/01/07/bjsports-2013-092972.short?rss=1">carries</a> up to 3778N (385kg). </p>
<p>In 2007, the International Rugby Board introduced the <a href="http://news.bbc.co.uk/sport2/hi/rugby_union/rules_and_equipment/5410346.stm">“crouch-touch-pause-engage” sequence</a> in all levels of rugby to control these large forces during scrum engagement. These rules were <a href="https://secure.ausport.gov.au/__data/assets/pdf_file/0009/142686/Australian_Rugby_Football_Union_Annual_Report_1992.pdf">trialled at the school level</a> in Australia in the 1980s and had an immediate effect on reducing catastrophic neck injuries to almost zero.</p>
<p>The high average number of high-energy impact events in a game demonstrates the dynamic and physical nature of both rugby codes and helps explain the high level of attrition experienced by players. As players <a href="https://theconversation.com/not-so-gentle-giants-how-rugby-players-are-getting-bigger-23978">get bigger</a>, train more intensively and get faster, the collisions are going to get harder. </p>
<p>Sports administering bodies must therefore improve their management of collision events, particularly at the lower playing levels, where players are less mature or not as well prepared physically for the demands of the game. This can be done by teaching and enforcing correct technique.</p>
<p>Increased muscular development allows players to better resist force and is something all players can easily attain. But it can also make them heavier and faster, so the impact forces can be greater. Ironically, it is the most highly trained, strongest and fittest players who are most frequently injured because of the increased collision energy. </p>
<p>Unfortunately, body padding does not provide the protection players would hope for. While it might absorb some direct impact to the torso or head, it will not protect the limbs or joints from injury, and may encourage a player to use unsafe techniques, taker greater risks and engender a false sense of security during an impact.</p>
<p>Tactics such as other players recklessly entering rucks and mauls, shoulder charges, or second and third tacklers coming in late to effect the tackle, all add to the risk of injury. Referees and judiciaries have tightened up on these dangerous tactics in recent years in an attempt to eliminate them from the game. </p>
<p>While it is impractical to alter the nature of rugby to the extent where all risk is eliminated, it’s easy to make the game safer without significantly altering the collision aspect that makes rugby so attractive.</p>
<p><em><strong>Further reading:</strong> <a href="https://theconversation.com/not-so-gentle-giants-how-rugby-players-are-getting-bigger-23978">Not so gentle giants: how rugby players are getting bigger</a></em></p><img src="https://counter.theconversation.com/content/24276/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Milburn 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>The legendary American Football coach Vince Lombardi once said “Football is not a contact sport, it’s a collision sport – dancing is a contact sport”. This is equally applicable to the various codes of…Peter Milburn, Professor, School of Allied Health Sciences, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.