I don’t want to ruin anything, but I think it’s finally safe to put away the balaclava. In the coming months, it is important to stay cool while exercising in the open air.
Warm weather workouts can be challenging, but they also have some surprising benefits. Here are five things you should know about the science of summer exercise:
You’ll get used to it
It’s no illusion: the same 20-degree heat that felt like a godsend in May will seem downright vibrant in August. Regular exercise in hot conditions causes a series of physiological changes that keep you cooler: your sweat glands kick in faster, your blood volume increases and your heart rate stays lower.
This process of heat acclimation begins after just two warm-weather workouts and peaks after about two weeks. But you can’t just lie on your recliner waiting to acclimate: The adaptations happen when you raise your core temperature, so you’ll need to exercise in the heat to reap the benefits.
It makes you fitter
Athletes preparing for competitions in warm weather, such as last summer’s Olympics in Tokyo, have long known that they must train in the heat. But a new study from researchers in Norway confirms an even stronger claim: Heat training makes you fitter, even when competing in cool conditions.
The study, published last month in the journal Medicine and Science in Sports & Exercise, found that cyclists increased their hemoglobin levels by 2.5 percent after five weeks of training in warm conditions, compared with a control group who did the same workouts in cool conditions. . Hemoglobin is the protein in red blood cells that carries oxygen to your muscles, so this increase translates to better cycling performance, regardless of temperature.
Movement is important
Another recent study, this one from researchers in Spain, collected eight years of training and racing data from 74 professional cyclists to investigate the effect of temperature on their power. Surprisingly, they found that performance did not drop noticeably until the thermometer rose above 25°C.
In contrast, a similar study of runners found that performance began to decline above 18 C. The difference? Cyclists generate their own cooling wind. Runners too, but at slower speeds. Whichever option you choose, consider the findings as an incentive to go faster.
Watch out for the sun
It’s not just the temperature, it’s the humidity, right? That’s true, but it’s also the sun. When you step out of the shade into the full sun, you will feel the difference. The air itself is not warmer; instead, you are directly heated by electromagnetic radiation from the sun, much like a microwave oven cooks food without heating the air.
A 2016 study by researchers in Japan had volunteers cycle to exhaustion in a 30°C heat under artificial solar lamps corresponding to varying degrees of cloud cover. Even with constant temperature and humidity, the volunteers only lasted half as long in full sun as in cloudy conditions.
The takeaway: Wear a hat, opt for morning or evening workouts, and factor in cloud cover in addition to temperature and humidity when checking the weather forecast.
Perception is reality
Perhaps the most fascinating line of heat-related research in the past decade has been the role of perception. Athletes are more likely to give up if the thermometer has been manipulated to display a falsely high temperature, or if they are fitted with a heating pad that makes them feel slightly warmer without actually raising their body temperature.
That doesn’t mean the physiological effects of hot weather workouts — dehydration, rising core temperature, and so on — aren’t real. But your brain will start applying the brakes well before you’re in danger.
It’s important to deal with hot weather: drink when you’re thirsty, seek shade if you can, and leave if you feel dizzy or nauseous, for example. But in most cases, the main consequence of summer training is that you get hot and sweaty. You may not like it, but it beats frostbite.
Alex Hutchinson is the author of Enduring: Mind, Body, and the Curiously Elastic Limits of Human Performance† Follow him on Twitter @sweatscience†
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