We all know exercise is good for your overall health. But what about the act of sweating itself? Does purposeful exposure to heat have health benefits? Studies show that exercise in heat stresses the body, but heat exposure can promote beneficial adaptations in fitness when managed strategically .
Extreme heat poses health risks, so approach heat training with care. In general, long, difficult race efforts at high temperatures should be avoided, as we see in cases such as the New York City Triathlon, which canceled its July 2019 event due to extreme temperatures. Exercise in the heat puts stress on the body that can cause heat-related illness like heat cramps, heat exhaustion and heat stroke if your core temperature gets too high.
Both exercise and passive heat exposure can cause the core body temperature to rise. The body responds with a higher heart rate to pump more blood through the skin and begin perspiration. If the air is humid, sweat cannot cool the body as effectively, causing more bodily stress. Bodily stress, however, isn’t always a bad thing. When treated as intentional training-related stress, heat exposure can bring impressive gains in fitness, so long as it’s monitored and balanced with proper recovery.
[Editor’s note: Running or exercising in the heat can be dangerous. Always consult a physician before beginning any new training plan.]
Here we explore how breaking a sweat is good for your health.
1. Sweating may improve VO2 Max, blood plasma volume, and adaptability to temperature changes
In 2010, Santiago Lorenzo conducted a heat training study with 20 athletes. After only ten days of heat acclimation, they showed remarkable gains in VO2 Max, increased blood plasma volume and the body’s ability to cool itself.
Following the study, Lorenzo told Outside Magazine heat training provides more substantial environmental improvements in aerobic fitness than altitude acclimation. Lorenzo concluded the body adjusts to temperature changes faster than it does to differences in altitude. In this particular study, cyclists improved their time trial results by 6 percent in cool conditions and 8 percent in hot conditions.
This is good news for runners who don’t live at altitude or have easy access to altitude training. Temporary exposure to heat is generally easier to access, whether it’s by exercising outdoors or relaxing in a sauna, hot tub or bath.