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Hot, humid days are already uncomfortable\u2014now imagine that discomfort multiplied as you go all-out during an evening pickleball<\/a> game or lunchtime run. For some, that heat can be enough to make you not want to exercise outside at all.\u00a0<\/p>\n But, now is the time to use that workout inspiration we\u2019re all getting from the summer Olympics<\/a>\u2014because, according to experts, working out in the heat can help us get fitter, if we do it correctly.<\/p>\n Higher temperatures and stifling humidity make the body work harder.\u00a0<\/p>\n \u201cI always think that exercise and heat is a big cardiovascular challenge,\u201d says Chris Byrne, registered physiotherapist and senior lecturer at the University of Exeter.<\/p>\n That\u2019s because our cardiovascular system has to juggle two substantial jobs: circulating blood, oxygen, and metabolic fuel to our muscles, and cooling our bodies down.<\/p>\n \u201cThere\u2019s competing demands. Some of\u2026the cardiac output from the heart needs to be channeled into losing heat,\u201d Byrne says. \u201cThat can start causing problems.\u201d<\/p>\n That\u2019s when what Byrne calls \u201cheart rate drift\u201d can happen.\u00a0 In cooler conditions, your heart rate will remain steady while maintaining the same effort during exercise. In the heat, despite running at the same speed, for example, heart rate starts to drift up. \u201cAnd that is a sign of the cardiovascular system putting more focus on heat loss,\u201d Byrne says.<\/p>\n \u201cOur physical fitness in the hot environment can certainly be improved through things like heat training,\u201d says Chris J. Tyler, who researches the impact of environmental extremes on the human body at the University of Roehampton in Britain.\u00a0<\/p>\n With properly paced and progressive training, our bodies can not only adjust to heat, but we\u2019ll also be able to work out harder at hotter temperatures, Tyler says.<\/p>\n Those adaptations interact to make your cardiovascular system function more efficiently, with a higher volume of blood leaving the heart per minute, Byrne explains.<\/p>\n Heat adaptation leads to a lower resting core body temperature in order to improve our ability to lose heat, Byrne says. Our body temperature can lower from the standard 98.6 F to as low as 97.7 F\u2014giving us a lower starting temperature as we begin exercising, meaning we\u2019ll start sweating earlier, cooling down earlier, and we won\u2019t get as hot as quickly.\u00a0<\/p>\n Byrne says we also start to sweat earlier at our newly lowered body temperature. That means our bodies have adapted to trigger heat loss mechanisms more quickly, which helps us cool down.<\/p>\n With these adaptations, you can reach much higher cardiac outputs\u2014or much harder efforts\u2014during exercise, Byrne says.\u00a0<\/p>\n \u201cThese adaptations allow the heart to function more efficiently to meet those dual tasks of supplying fuel to working muscles and losing heat from working muscles,\u201d Byrne says.<\/p>\n Heat adaptations can occur quite quickly, says Tyler, if you do it right.<\/p>\n \u201cThe adaptation isn\u2019t getting hot\u2014it\u2019s getting hot and staying hot,\u201d Tyler says. \u201cIt\u2019s not how long you exercise for, it\u2019s how long you\u2019re hot.\u201d<\/p>\n Byrne advises to work out for at least 30 minutes every day, or 60 minutes every other day, if you\u2019re running or cycling\u2014at whatexperts would call \u201csubmaximal effort.\u201d\u00a0<\/p>\n Even if your heart is pounding in the heat, your core temperature may not be high enough to reap heat adaptation benefits. It\u2019s most ideal to get that core temperature high and keep it high for at least 30 minutes, Byrne says, since it takes a longer time for body temperature to rise and fall than it does heart rate.\u00a0<\/p>\n You can start to see those benefits as soon as five to seven days into daily training, Tyler says. If you\u2019re exercising more like every other day, then he says you can expect to see those adaptations in about two weeks, maybe sooner.<\/p>\n When it comes to other types of exercise\u2014like pickleball, tennis, or football\u2014which include high intensity intervals<\/a>, Byrne says heat adaptation is possible, even with brief rest periods between sets or games, since body temperature takes a while to fall.<\/p>\n \u201cWith something like tennis, you\u2019ll probably see a rise in body temp, and if there\u2019s a break in between sets you\u2019ll probably see a subtle fall, but quickly it\u2019ll be back up again,\u201d Byrne says.<\/p>\n Even with adaptations, training in hot conditions is hard, especially when you first start out. Tyler says the key is to start slow, gradually increasing the difficulty.<\/p>\n \u201cJust like you wouldn\u2019t go to the gym and instantly try and lift 400 pounds, you might start light and get heavier as you progress,\u201d Tyler says. If you go too quickly, he warns, you could get injured or suffer from heat-related illnesses. On the other hand, if you don\u2019t increase the difficulty at all, you likely won\u2019t see your fitness progress much.<\/p>\n Starting slowly can look like going for a 30-minute jog with walk breaks, Byrne says, and then building up gradually from there.<\/p>\n The average athlete should pay attention to heart rate and rate of perceived effort, or RPE, Tyler says. Once you see your heart rate lower during the same workouts and feel that they become easier than when you first started heat training, that\u2019s when you feel those adaptations happening in real time.<\/p>\n Safety should be your number one priority. Heat illnesses are real\u2014and can be deadly in the most extreme cases.\u00a0<\/p>\n Byrne advises to only exercise in what you can handle\u2014if you feel you\u2019re overheating, slow down or stop immediately and cool down. Humidity can be a dangerous factor as well, he says, as the moisture in the air prevents you from sweating\u2014one of the most vital things our body does to cool down.<\/p>\n Here\u2019s advice from experts and the CDC<\/a> on how to stay safe while going after summer goals:<\/p>\n\nWhy is exercising in the heat so hard?<\/strong><\/h2>\n
What is heat adaptation?<\/strong><\/h2>\n
That\u2019s where three vital physical adaptations come in:\u00a0<\/h3>\n
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Here\u2019s how safely heat train<\/strong><\/h2>\n
How to stay safe in the heat<\/strong><\/h2>\n
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