It’s getting hot out there. Bundle up.
Heat training can improve your fitness, help you adjust to altitude, and improve your racing, even in cold weather.
The body responds to stress with the production of heat shock proteins (HSPs). HSPs are so named because they were first identified as a response to heat stress, but are produced in response to many stresses. but they are thought to be responsible for a number of beneficial physiological responses including increased blood volume and quicker and more effective perspiration (1). The latter is an important part of heat acclimatization.
Increase blood volume is similar to what you get with altitude training/living. This may be due to the fact that when it’s hot, more of your blood is diverted from your muscles to help dissipate heat. Thus, your body reacts to the decreased blood/O2 available to working muscles by producing more blood. Some (not all) research has shown similar effects to what you would get training/living at altitude. And, the benefits from heat training seem to occur faster than with altitude training, though maybe not as great. It seems to help regardless of whether racing in hot or cold, high or low.
There are several ways to do heat training.
- Train when it’s hot. Do it on your long or medium relatively moderate intensity. Do not do your hard workouts in the heat as it’s hard to get enough intensity safely when it’s hot. Also, don’t do your easy/recovery workouts because training in high heat is high stress.
- Bundle up with extra clothes to simulate heat. Former elite runner Benji Durden used to bundle up during the hot and humid Georgia summers (2,3). That may be extreme. 100-mile world record holder Camille Herron covers up if it’s below 80-ish (4). This is especially effective over the winter (6)
- After a run, spend time in a sauna or take a hot bath. Ultra coach Jason Koop recommends 20-30 minutes. This may give similar benefits to training in the heat with low stress (5, 6).
Heat training affects people differently, so be alert to how it affects you personally. Start small to let your body adapt.
Stay hydrated in the heat. The goal is exposure to heat, not dehydration. Dehydration is damaging.
Train smart. See you on the trails (and roads).