Researchers discovered that the cyclists who worked through the heat improved their performance by 7% (a noticeable and significant amount in cycling), while the control group did not show any improvement. What surprised researchers most was that the experimental group not only showed that they had achieved a level of heat acclimation, but the training also helped them to function better in cooler environments.
Here are the magic numbers you need to know to maximize your heat acclimation:
101. The number of degrees Fahrenheit you need to elevate your core body temperature during training sessions, says Minson.
60. The number of minutes you want to have that elevated core temperature maintained during your heat training to make sure that you’re truly getting the heat acclimation benefits, says Minson.
5 to 10. The number of days you need to train in the heat. “To really heat acclimate the way we’re talking about, someone has to really go out and exercise in the heat for five to ten days, with pretty significant exposure at times,” Minson says. Just be sure to follow warm-weather precautions to keep from overly stressing your body.
Elevating your core body temperature so much that you pass out (or worse!) during a workout is not going to score you any points in the fitness department, so it’s up to you to know your limits. “People just need to be wise enough to listen to their bodies,” says Cedric Bryant, Ph.D., a fitness expert for the American Council on Exercise. “It isn’t a ‘no pain, no gain’ situation.”
Try these tips to stay safe when the heat is on.
Drink up. You obviously sweat more as it gets hotter and more humid, so you’ve got to make sure you’re replacing all those fluids as you run, bike, or do other workouts in such extreme weather. Dr. Bryant recommends consuming 16 to 24 ounces of water a couple hours before exercising in hot temperatures. Past that, he says to take in another six to eight ounces of fluids every 15 to 20 minutes of exercise.
Mind the humidity. Humidity is also a huge factor to take into account, and it’s something Minson’s study didn’t test for. “The principle way in which the body cools itself during exercise is through sweat,” Dr. Bryant says. Bryant says to consider moving activity indoors on days that are extremely hot and humid, since it just makes the environment particularly stressful on your body.
Don’t go overboard. Finally, know that you can still be in good shape without heat acclimating. Minson and Bryant each say they only recommend it to very fit, competitive athletes who need to be ready for weather extremes and/or want to get an edge.