Summer’s heat is sizzling right now in much of the United States, making outdoor exercise difficult and draining.
Some of these techniques lower your temperature. Others make you feel as if you’re cooler, without actually changing how hot you actually are. None last long, or take the place of common-sense strategies for avoiding overheating, such as exercising early or late in the day, or strategically acclimating to high temperatures.
But if you plan to work out in the heat or have a summertime race or match coming up, the right mix of these cooling strategies at the right times could keep you feeling fresher and faster for longer.
The menthol method
One of the most surprising ways to make yourself feel cooler is menthol. A natural chemical found in peppermint oil or synthesized commercially in labs, menthol substantially reduces how hot we feel, studies show, by activating specialized receptors found in our skin cells and in the mucus membranes in our mouths.
These receptors are designed to pick up subtle changes in the temperature of the outside world and send messages to our brains telling it whether we should be feeling hotter or colder.
In ways that aren’t fully understood, menthol turns on the cold-related versions of these receptors, which then alert our brains that the world may not be as hot as our brains had been thinking, and we should start feeling cooler.
Athletes “increasingly are using” menthol, in various forms, to keep their cool during hot-weather training and competitions, said Martin Barwood, a professor of applied physiology at Leeds University, who studies exercise and heat.
In studies, athletes who drank or even rinsed their mouths with a beverage containing menthol while racing in overheated labs finished faster and reported feeling much less hot than athletes who weren’t using menthol, while a 2020 review of research co-authored by Barwood concluded that menthol “reliably improves thermal sensation.”
“Menthol definitely helps athletes feel cooler and more comfortable,” Barwood said.
Helpfully, menthol also is easy to come by. Do you remember your parents smearing Vicks VapoRub on your chest when you developed a cold as a kid? One of its key active ingredients is menthol. The same is true for peppermint tea, many brands of mouthwash, Hall’s mentholated cough drops, and some new sports drinks and sports goo’s. Look for the word “mentholated,” or menthol in the ingredient list.
As for how to cool yourself with menthol, you could fill your water bottle with “cooled peppermint tea” said Russell Best, an exercise scientist at Waikato Institute of Technology in New Zealand, who’s studied exercise in hot conditions. Peppermint is rich in menthol and also “affordable and accessible,” he said.
You could also melt a few Hall’s extra-strong cough drops in warm water, ice the mixture and either drink or just swish and spit the resulting beverage, said Maria Roriz, a nutrition researcher at the University of Porto in Portugal and team nutritionist for the FC Porto professional soccer club, who’s studied menthol and sports performance.
Because our mouths are full of the specialized cold receptors, we don’t need to swallow menthol to start feeling cooler, she said. “Rinsing seems to be enough to ensure the menthol cooling mechanisms” kick in, she said. In other words, you can swish a capful of menthol mouthwash or strong, chilled peppermint tea around in your mouth for a minute or so, expectorate and feel cooler while you run, ride or take on all comers in pickleball.
Slushies and smart decisions
Menthol’s effects don’t last, though, usually wearing off within about 15 minutes, Best said. At that point, you’ll need to chug more chilled mint tea or rinse your mouth with the travel-sized mouthwash you’ve discretely secreted in your shorts.
You could also start out cooler by having a slushie before heading out the door, Roriz said. Slushies, which combine crushed ice and water, lower your body’s core temperature by “absorbing a considerable amount of internal heat,” Roriz said.
But their benefits are slight. In a 2015 study, male runners were slower during a 5K race in a hot lab when they consumed a slushie than when they rinsed their mouths with menthol. Slushies also aren’t portable an icy slushie soon becomes a tepid puddle in the heat.
Fundamentally, both slushies and menthol are short-term fixes to the rigors of hot exercise, Barwood said. They make you feel better. They do not make the environment less sizzling. So, be cautious and smart, he said. Hydrate. Slow down if you feel tired. Acclimate with long, hot baths to prepare your body. Exercise in the morning or evening when temperatures are lowest and reroute your usual runs or rides so there’s plenty of shade.
Above all, “know your limits,” Barwood said. If you begin to feel ill, achy, crampy or nauseated, which can be symptoms of heat illness, stop, find shade, hydrate and seek medical attention if you continue to feel unwell.
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