How to Get Used to Exercising in the Heat
No one likes to feel sluggish and sweaty, so when the sun goes down, we know you’d be better off doing your workout in an air-conditioned gym. But if you can handle it in the heat, your workouts will not only be easier, but your endurance will also increase when the mercury drops again.
Hot workouts can be dangerous, so we hope you have some sound advice about running in hot weather. Among the most important: drink to stop yourself thirsty (or a little more) and stop and seek help if you start to experience symptoms of heat sickness, such as nausea, dizziness, or weakness. And while it’s great to work on your ability to run in the heat, don’t be foolish – stay home if the temperatures are higher than you can handle, and keep an eye on smog and ozone levels (which worsen on hot days) if you live in an urban area.
Why exercise in hot weather seems so unbearable
Running is bad, and the heat is negligible, so running in the heat is a shame. But that’s not all: training in the heat seems even worse than it should be.
Your brain perceives stress differently in heat, so even before overheating, you feel sluggish. In a studypublished in the European Journal of Physiology , cyclists who trained in a laboratory at 95 degrees were slower than when they did the same time trial at 59 degrees. This makes sense, but here’s what’s strange: they didn’t overheat, and then they slowed down. They were slower from the start . It seems like our brains are slowing down our bodies by actively trying to conserve energy just because we know it’s a hot day.
As we continue to exercise, our bodies heat up. When asked to cycle to exhaustion, participants pooped when their core temperature reached 104 degrees, no matter what temperature they started at. In this study,published in the Journal of Applied Physiology , the athletes who took the longest to reach that temperature were the ones who wore the fancy water-cooled jacket. You can mimic this effect in your workouts by drinking ice cold drinks and pouring water on your head . The longer you can keep your body cool, the longer you can sustain heavy effort.
But cooling the body is not a complete solution. A cup of ice cold water over your head or belly brings only short-term relief, and water-cooled jackets are not practical outside of physiology labs. Let’s see what happens in real life.
Your body is trying in part to cool itself through sweating. When moisture evaporates from your skin, it carries a little warmth with it. However, in humid weather, sweat does not evaporate so easily because the air is already filled with water vapor. So when we talk about “warmth,” we actually mean more than “perceived heat,” which is a combination of heat and humidity. This heat index chart shows the relationship:
In hot (and humid) weather, you will run slower. While you may find charts like these that predict exactly how much slower you will be, it really depends on how much you are used to the heat and your body size.
That’s right, not your physical shape, but your actual size. Larger people have more muscle, fat, or both. Muscles generate heat, while fat acts as an insulator. Smaller people, on the other hand, generate less heat but have more skin through which this heat can be dissipated – the same surface area to volume ratio . Younger runners do better on hot days.
Some people think that being physically fit will help you cope better with heat, but the opposite is true: the more fit you are , the more heat you generate just because you work so well.
Aside from changing body shape (which is possible , but not likely to be corrected in the short term), what can you do to better cope with the heat? The answer is simple: spend more time exercising in the heat.
How to adapt to the heat
Running in hot weather helps you run better in hot weather – and it makes you a better person, period.
Let’s say you’re training outdoors this summer, and your twin is in the same athletic form doing identical workouts on a treadmill in an air-conditioned gym. Who do you think will finish first in the 5 km race on a hot weekend in August? That’s right, you will.
But even if the weather is unseasonably chilly on that August day, heat training can still help you beat your twin. Part of the magic of heat training is that it increases the amount of blood in your veins (it’s best to direct it to your skin for cooling, but still leave enough to fuel your muscles). The effect is similar to the mild, completely legal version of blood doping .
Bad news: Adapting to the heat takes effort. It’s not enough to sit in the air conditioner all summer, going outside only for infrequent workouts. A studypublished in the European Journal of Applied Physiology found that people who did not exert much effort to exercise in hot weather did not tolerate the heat in the fall better than in the spring. If you want to reap the benefits of heat training, you must work on it.
This U.S. Army training protocol provides a good roadmap for heat adaptation: it says spend at least two hours a day in the heat and include cardiovascular exercise (like running, cycling, or anything that increases your heart rate). abbreviations). as part of it.
You can expect to be able to better adapt to the heat after about two weeks, although you may be able to see results after just a few days.
Don’t expect to be able to do the same workouts at first: remember that your body is still trying to convince you that you are very tired and need to slow down. The worker safety manual is a reality check here. On the first day of the heat, the Occupational Safety and Health Administration (OSHA) recommends giving workers only 20% of their normal workload. Over the course of the week, they should gradually increase to 100%.
In addition, to adapt to the heat, you must spend time in it. You can take a few days off, but if you relax for a week, you start to lose your superpowers in hot weather: the army estimates a loss of about 75% in three weeks.
To proceed with heat training in cool weather, you can try to wear long sleeves and tights, as did elite runners Kara Gusher in preparation for the World Championships in Osaka stuffy. (She won the bronze medal, the first American woman to do so.) She also spent a few weeks in Osaka before the start of the race – an option worth considering if you’re an avid athlete on vacation.
You can also try the opposite of our advice to stay cool by running in the hottest part of the day on tarmac roads with no shade. Stay safe and enjoy your new super powers!
Illustration by Tara Jacoby.
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