Aim for Acclimatization
We also should accustom ourselves, slowly, to unfamiliar swelter, Dr. Gibson says, a process known to exercise scientists as acclimatizing, which involves working out sometimes, by choice, when the day is warmest. This approach helps to condition our bodies to better cope with the heat. Once acclimatized, we will sweat earlier and more abundantly than before, dissipating internal heat better and leaving us feeling bouncier and less fatigued.
Acclimatizing should be gradual, however. To start, slather on sunscreen, fill a water bottle, head outside after about 10 a.m., when temperatures intensify, and try to complete a gentler version of your standard workout, says Carl James, a senior physiologist at the National Sports Institute in Kuala Lumpur, Malaysia, and co-author of the review. If you usually run for 30 minutes, for instance, maybe jog for 20, and monitor how you feel. If your heart seems to be racing, he says, or you feel lousy, “slow down.”
After a few acclimatization sessions, you should notice your clothes and skin are drenched, Dr. Gibson says. Congratulations. “Earlier and more profuse sweating is a great sign that heat adaptation is taking place,” he says. Most of us acclimatize after about five to 10 hot workouts, he adds, although women, who tend to sweat less freely than men, may require an extra easy session or two to be fully prepared for harder workouts in the heat.
Take a Warm Soaking
After each acclimatization session, head for the showers, but dial up the heat. Standing under a warm shower spray or soaking in a hot bathtub for 10 minutes or so after a sweltering workout prompts our bodies to continue acclimatizing, Dr. Gibson says. “It extends the stimuli for heat adaptation,” he points out, “and is therefore welcome and beneficial.”
Slurp a Slushie Beforehand, Consider Cold Underwear
An icy beverage before a hot workout “will help with hydration and provide a combination of perceptual and actual cooling,” Dr. Gibson says. Aim to drink about 16 ounces of cold fluid 20 minutes or so before you head out. Drinking closer to the session’s start could cause stomach upset during your workout.