How to train for the heat indoors

Sure, most of your workouts take place in the comfortable, climate-controlled environment of the gym. But it’s nice to take those runs and lunges out into the fresh air sometimes. Enter summer, the steamy, stifling season that draws extra sweat from your pores and sucks the energy from your previously 10k-ready body. Is there a way to prep yourself for the summer heat and avoid that soul-crushing moment when you suddenly feel, after all of 10 steps, that you’re running under water? Can this be done at the gym, before you even set foot outdoors? To some extent, yes.

“Heat puts cardiovascular stress on the body,” says Jason Martuscello, a strength and conditioning specialist and Tier 3 trainer at Equinox in Miami Beach (where it gets really, really hot). “Getting your heart rate and thermoregulatory response up while you’re still inside can help get you ready for the heat.”

How? Spend a couple weeks mimicking the hot outside environment by adding a layer of clothes to your normal workout wear. Martuscello recommends sweatpants and a sweatshirt—gear that’s not so bulky that it’ll mess with your range of motion or gait.

Once you’re ready to take the party out into the heat, opt for a two-week transition period. For the first week, you’ll split workouts between indoors and outdoors, 50-50. Hop on the treadmill and get in half of that 10k, then finish the rest at the park. During the second week, you’re good to do the full 10k outside, but take it easy. Come week three, you’ve got Martuscello’s green light to turn the intensity up.

Another indoor activity that can help: hydrating. Drink tons of water (even on your off-days). “Once you think you’ve drank enough, drink more,” Martuscello says.

You’ll probably want to toggle between indoor and outdoor workouts all summer long. You can do that without losing ground on your heat-ready condition by making sure to really turn up the intensity when you’re in the nice, cool gym.

Lucky for fresh-air lovers, training in the heat can actually be really, really good for you.

“If you can condition your body to meet the demands the heat places on you, you’ll be able to run longer and run faster once you’re back inside,” says Martuscello. “In other words, the heat can actually get you a better workout and result in lower resting heart rate and more efficient regulation of body temperature.” Working out in a cooler place, whether at the gym or outside come September, will also feel a lot easier after your intense summer sweat sessions.

“It’s actually a technique that many athletes use to gain an edge,” Martuscello says. “Train high, compete low.”