During this period, with regular exposure, physiological changes occur that help your body better deal with heat stress. For example, you sweat faster and the evaporation of this liquid from your skin allows for better cooling. Other indications include your skin and core temperature remaining lower and your heart rate and blood flow more stable.
All of this means it’s important to exercise in hot weather, Seely says; she wouldn’t have attempted a tough interval training session at the start of the summer.
Whatever your usual routine, take a few steps back the first few times you train in the heat, suggests Seely. Go for less time, fewer miles, or less intensity (perhaps more walking instead of running, for example). Over a period of a week or two, you’ll probably start to notice things feeling easier, and you can gradually start to come back up again.
However, even after you acclimatize, any given workout will likely be even harder in the heat, Kylee Van Horn, Dt.P.dietitian, certified running coach, and ultrarunner in Carbondale, Colorado, says SELF. It’s not necessarily bad, just something to keep in mind, so adjust your expectations and don’t dwell on hitting the same times or paces you might be able to do in cooler weather. Finally, if you still want to go really hard and it’s really hot outside, do your workout indoors.
2. Be warm when not exercising.
Although it may seem counterintuitive, you can speed up the acclimatization process by also spending time between workouts sweating it out. At a university in Birmingham study, the researchers asked 20 trained runners to jump in the sauna for 30 minutes after an easy run. After three weeks, they were more tolerant of heat, as measured by their core body temperature and heart rate during hot workouts. In addition, they ran faster in more moderate weather conditions.
When she was preparing for the Speed Project in 2021 – a 300+ mile race from Los Angeles to Las Vegas – ultrarunner Jes Woods used this method, adding 30 minutes in a sauna after each day of running for a 10-day period. And the athlete and ultrarunner Adidas Terrex Abby room goes to the sauna for 20-30 minutes for the last few weeks before a big event like the Western States 100 (a 100.2 mile event with temperatures over 100 degrees) or a Fastest known time race in death valley.
You don’t have access to a sauna? Simply sitting in a steam room can also work, Woods says. However, as Howard points out, research suggests that the water should be around 104 degrees, a temperature that might be difficult to maintain for the 20 to 40 minutes required. (Also, the water temperature should not be higher than this, according to the CDC.)
That doesn’t mean, however, that you can’t harvest some benefits without going super intense with it. Simply spending 60-90 minutes in the heat doing physical activity that isn’t as strenuous as your regular exercise (eg, going for a walk) can also stimulate similar physiological changes. And the simple act of sitting outside with a book or a smoothie could also be beneficial in helping you shift your mindset. « To sit in [high temperatures] will likely give you more mental capacity to endure and enjoy than any actual physical adaptation, but mental resilience is also very important,” says Howard.
3. Hydrate, hydrate, hydrate before your workout even begins.
Preparation is key to staying hydrated in the heat, hiker Natalie Smart, owner of a travel company called Hike to destination, says SELF. While hydration during every hike is essential – she advises participants on her hikes to bring two liters of water on every hot-weather adventure, no matter the distance – it’s not something you can cram. Instead, get off to a good start by staying on top of your fluids beforehand. « People don’t realize that it’s the day before that can set you up for success or failure, » she says.
