What the Olympic athletes in Tokyo reveal about heat waves and climate change

This summer’s Olympics may be warmest in decades. Tokyo, where the games are held, can see dangerously high temperatures, i over 90 degrees.

The athletes will likely be prepared. Scientists like Oliver Gibson, a training physiologist at Brunel University in the UK, has spent decades researching how athletes can adapt to extreme heat conditions. He says that the human body with training has a remarkable capacity to cool itself when the temperature rises.

These days, though, Gibson is less worried about the athletes. While running a marathon in 90 degree heat can be dangerous, even in preparation, there is a much greater threat to ordinary people dealing with the new realities of climate change. “Much of what we do now takes the decades of insight that we have gathered from the athletes and begins to apply it to the general population,” says Gibson.

Dealing with heat stress is a growing problem that “will affect more than just your dozen around Olympic finalists,” he says. “Millions, billions of people will undoubtedly be affected by climate change.” Heating situations are already the deadly weather events and are likely to continue to get worse. To beat the heat, we have to confront it, Gibson says. He believes that research into elite athletes can help make our bodies more resilient in a warming world.

This conversation has been edited for length and clarity.

Brian Resnick

Can anyone adapt to the heat, or is it just top athletes?

Oliver Gibson

Yes, anyone can adapt to the heat. We have recently published work on elderly British residents who had very little heat exposure. We asked them to train on the treadmill for a short period of time. Also [they sat] in a hot bath to keep their body temperature high. What we have shown is that they can adapt to the heat within five days [under the supervision of medical professionals].

Brian Resnick

When you say “adapt to the heat”, what do you mean?

Oliver Gibson

What we seem to do with heat adaptation is to improve the body’s baseline. If an athlete trains in the heat for two weeks, we know that their body temperature will be reduced by maybe about 0.5 degrees Celsius as an average. Some a little more, others a little less.

What it does is drop the existing body temperature so that when they are always heated, they have a larger window. They can train for so much longer it takes for them to increase by that amount.

And then a body starts sweating faster. Only a small change in temperature starts sweating. And the signal of sweat will also come to a greater extent. So it will not be sweating minimally later; it will be sweating maximum faster. The rates of dehydration will be higher and faster.

Brian Resnick

Are athletes better at adapting to the heat?

Oliver Gibson

Athletes have earned their advantage by decades and decades of training. They have more blood so they can pump the blood more efficiently around the body. So they are not limited in that respect; they have a larger heart that will generally beat more often so that their heart effect can respond to the heat.

For the public, it might take three or four exposures to the heat to even really see the signs that they are adapting. While an athlete who trains regularly, the adjustment is right there.

People with previous exposure to heat stress are able to induce the same amount of adaptation more quickly. So if they have already lived in a warm environment, they adapt a little faster.

Brian Resnick

I’m curious to learn some of the basics here. How does the human body normally cope with the heat?

Oliver Gibson

The human body is really efficient at dissipating heat. We are the very best mammals – the best creatures – to sweat on the planet. So if someone is training in very cool conditions or even temperate conditions, they may sweat enough to lose heat. As long as they are not exposed for too long or become very dehydrated.

Brian Resnick

What happens if they is exposed for too long?

Oliver Gibson

As body temperature begins to rise, we see a greater distribution of blood to the skin. Blood vessels open up. When someone gets hot, you see the red blush of the skin.

And when a drop of sweat evaporates from the skin, the space below, the blood, cools. Cooler blood circulates and cools down in the body.

Brian Resnick

But that system sometimes fails.

Oliver Gibson

We do not have this infinite capacity to increase our heart volume or the amount of blood pumped by the heart. We get to a point where there is just an insufficient cardiovascular response to cool us optimally. And that is at the time when body temperature begins to rise.

For many people, the challenge comes when both exercise and heat are combined. The challenge with exercise is that you have competing requirements for that blood supply: from the skin from cooling down, but also from the muscles to the activity of the movement.

It gets worse when the environment is hot and humid, so that when the sweat leaves the body, it leaves more slowly, so there is not so much cooling. If the area is 100 percent saturated, if the humidity is very high, all that sweat drips on the floor and does not give it evaporation cooling.

Brian Resnick

What is the worst case scenario?

Oliver Gibson

A clinical diagnosis of hyperthermia comes from high body temperature and neurological dysfunction – effectively the brain gets too hot. We have this area of ​​the brain, the hypothalamus, which is our thermostat. And the high temperature can actually disrupt this treatment system, so in fact our bodies would go in the opposite direction and we would actually stop sweating. The signal is confused by extreme heat. It is an almost deadly condition.

Brian Resnick

Something I hear here is perhaps: Good cardiovascular health will be important for people who adapt to a warming world to deal with worse heat waves.

Oliver Gibson

Absolutely. A person – especially in a mid to late phase of life – who has a more robust cardiovascular system will have a generally more robust body, whether it is the challenge of temperature or other things thrown at it.

Brian Resnick

Often during a heat situation, the public health message is that we need to be inside as much as possible. And I imagine it is useful because many people are not adapted to the heat.

But when we see how heat waves become more common, can we take advantage of confronting it a little more and trying to adapt?

Oliver Gibson

I think my philosophy is that the body can respond to heat stress. As long as we embrace it in a measured way and we are wise with how we approach the heat, we should not be in a situation to just avoid. Embracing stress is definitely the right approach.

Brian Resnick

Can it be dangerous to try to adapt to the heat? There is a bit of a riddle here: To get better at handling heat we need to train in the heat, but the heat is dangerous if we are not trained.

Oliver Gibson

If you want to adapt to the heat, it is important to listen to your body, to do things gradually and slowly. We will never say that you should not try to adapt to the heat. But going out and being a little gung-ho or blasé over it, I think, would put you at great risk. So what we always suggest is to do things in a measured way. If you are not already exercising regularly, this is probably the very first step before you start adding heat to the mix.

But if someone is used to exercising – even if it goes fast – doing so in a warmer environment should not come with any major risk as long as you are listening to your body. And the moment you start to feel overheated – if you feel light hair, if you start to feel uncomfortable in every respect – call it back right away, seek shade, make sure you are hydrated.

We would be comfortable saying to recreational athletes, maybe go for the same duration of running in the heat, but call the intensity back a bit. Calibrate your expectations until you start seeing the adjustments. So when you start to see that you sweat more – and if you measure your heart rate when it looks like it might look cooler – it’s a good signal that your body is starting to react. You can push a little harder.

Brian Resnick

Do you have general tips to help people cope with the heat, perhaps when they are not so well adapted to it?

Oliver Gibson

Drink often. Have a planned drinking strategy and a cool drink with you. Then the other thing is to make the skin cool. To do so, of course, you can seek shade and air conditioning. Even if it is not available, do not be afraid to rub exposed parts of the body – arms, legs, face – with very cold water. It’s something incredibly simple.

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