Heat training can help athletes — and the rest of us — adapt to hot weather

Athletes kick, run, bike, jump, flip, and otherwise push themselves to reach their goals during this summer’s Olympic Games. For some athletes, those events can push the limits of their heat tolerance.

“[The] the combination of heat and humidity can really overwhelm an athlete quickly,” says Dr. Francis O’Connor, professor of military emergency medicine and medical director of the Consortium for Health and Military Performance Uniformed Services University in Bethesda, Md. -author of a recent piece in a medical journal JAMA on heat-related illness in athletes.

O’Connor says extreme heat is more likely to occur in the tournament. “In Paris, you’re going to get a medal. Or if you’re a soldier trying to finish your course, or trying to get [personal record] in a marathon – you’re going to push, and you can push yourself to the limit,” he says.

Heatstroke is a very serious condition in which a person’s core temperature is generally 104 degrees or higher and they are in an altered mental state; can lead to organ failure and death. It can happen even if you don’t do competitive sports, but stay in the heat for too long without proper hydration.

One of the best ways to prevent complications, O’Connor says, is to receive heat, also known as heat training. The concept involves controlled exposure to heat stress, which causes changes in the body that help it cope with hot and humid conditions. In fact, the medical department of the Olympics has published guidelines that recommend pre-heat training for athletes coming to Paris.

Heat training is not just for competitive athletes. Recommended for military personnel and those who work outdoors in hot weather. It may even help healthy community members, O’Connor says. He says: “People should not be afraid of the heat. “We can develop and increase adaptive responses to help us thrive in heat. But it has to be controlled.”

When done right, heat training can help people stay comfortable during the long, intense heatwaves that mark the unusually hot summer of 2024 and future heat waves that are expected to become more frequent as a result of climate change. the weather.

A solution with caveats

There are two important points to consider before exploring the topic of heat training.

One is that it is not for everyone. Heat illness is serious and can be fatal. And it can appear quickly.

“Everybody needs to be aware and self-examination and work with their health care providers,” says Eugene Livar, an epidemiologist and chief heat officer in Arizona’s notorious heath area. coaches and others to consider their views.” Also, when people work long hours in the sun, or otherwise exert themselves too much in the heat – that can lead to heat stroke, which is considered a serious medical emergency.

The second is that the ultimate goal of our planet, say climate scientists, is not to say, oh, it’s getting hotter, so it’s up to individuals to figure out how to deal with it. how is it. Scientists stress that as climate change continues to raise temperatures, the world’s last strategy to prevent warming is to reduce pollution – especially from burning fossil fuels – by this is responsible.

But in the meantime, it’s too hot out there. In recent weeks, temperatures in Las Vegas, Nev., and Delhi, India have soared above 120 degrees.

Health adaptation to heat

Heat and health experts say that careful exposure to heat can gradually lead to adaptations that help the body better tolerate hot days. “There is evidence to suggest that it can improve overall blood flow, boost your immune system and heart health,” says Jason Kai Wei Lee, director of the Center for Heat Resilience and Performance Center at the National University of Singapore Medical School.

Research on heat tolerance has focused on athletes, members of the military and outdoor workers, says Lee. Most people may not stay as long in the heat as those groups, he says. But the same principles apply. Gradually increasing the summer heat, and there is a period of rest between cooling, can help to adapt.

It’s difficult to develop a one-size-fits-all model, as a person’s heat tolerance depends on factors such as age, basic physical activity, and how healthy their immune system is, Lee said. we.

Sweating profusely is the key

A person’s sensitivity to overheating can vary from day to day, depending on factors such as sleep quality, fatigue and illness, O’Connor of the Uniformed Services University says.

“When I was examining veterans who had heatstroke, most of them had infections,” he says. “Colds, epilepsy, sinus infections, periodontal disease, blisters — things.” these raise the temperature of your body,” he says, so increasing the temperature or heat stress, on top of that it is possible that a person will enter the life stage. heat illness.

Your risk of overheating also depends on what you’re trying to do in the heat — going for a walk with a friend or going for a long, fast run — as well as external factors such as the temperature and whether somewhere honestly. cool down.

And since the body relies on evaporating sweat to cool itself, it matters how hydrated a person is, what they’re wearing and how humid they are.

But the bottom line is that you can’t improve your endurance without sweating. “You have to get stronger, but at the very least, you have to get out there and sweat,” says O’Connor. “If you don’t encourage sweating, that’s not enough physiological stimulation.”

Take it slow

The advice from Lee of the National University of Singapore is to take it slow and easy, with long rest breaks in between. “Broadly, the five methods we recommend would be aerobic conditioning, heat acclimation, activity relaxation, cooling and hydration – in that order,” he says.

Lee says it’s best to practice before very hot days. One recommended method says: “Exercise slowly every day in a hot place.” On Monday, walk for 15 minutes, rest on Tuesday, walk 30 minutes on Wednesday, rest on Thursday – you get the idea.

With a few weeks of normal temperature, the body begins to adapt and cool itself more efficiently. “The most obvious one is to increase your ability to sweat. As sweat evaporates, it cools the body,” says Lee.

Circulation improves and blood volume increases, so the heart does not need to work as hard to pump blood around the body.

The gradual exposure to heat will also help people learn how their bodies respond to heat, and to drink water when they’re thirsty and slow down when it’s hot, Lee says — all things that help keep the core temperature low.

Always watch for signs of overheating

Research shows that it takes several weeks of exposure to acclimate to exercise in the heat – and perhaps a week or more of heat exposure to lose it.

So while heat training may help some, it won’t be a cure-all for extreme, sudden, and climate-changing heat.

Rather, it’s part of a larger strategy for approaching hot days safely. “When it comes to the heat, stay cool, stay informed, stay hydrated and smart, and stay connected by checking on your friends, family and neighbors throughout the heat,” Livar of Arizona says.

And if you’re out of heat – watch out for signs of heatstroke in yourself or those around you. “If you’re getting extreme headaches, extreme fatigue — this is the time to tell yourself you have to take a step back, calm down, slow down,” says O’Connor.

And watch carefully for signs of mental changes that may indicate heat stroke.

He says: “If you’re going out with a friend and you notice that the friend can’t communicate well, maybe they’re wobbly, they seem confused, they have a change in their personality—which is related.” .