Heat training involves training in a warm environment, which forces your body to adapt to heat and become more efficient at regulating temperature and fluid balance. The main goal? Stimulating the production of hemoglobin and hematocrit—two key factors in oxygen transport in your blood.

Research shows that a well-executed heat training protocol can increase hemoglobin by up to 5.7%—comparable to or even better than altitude training. It also improves endurance performance not only in hot conditions but in moderate temperatures too.

An effective plan includes an initial five-week phase with five sessions per week. Each session lasts 50–60 minutes at submaximal power (55–65% of your FTP/lactate threshold). Heat is increased by training in a 35–40°C environment or by wearing extra warm clothing. Crucially, your core temperature should rise to at least 38.5°C and stay there for at least 40 minutes. This often means reducing your power output during that time to prevent overheating.

After this intensive phase, there’s a three-week maintenance period with three sessions per week. The aim is to maintain the benefits, with slightly reduced training load.

Hydration and weight monitoring are also critical. Fluid loss shouldn’t exceed 3% of your body weight, and lost fluids should be replaced with 1.5 times the amount lost. Iron supplementation (100 mg per day) is also recommended to support the hemoglobin increase.

But what’s in it for amateurs? Let’s be honest—five times a week, 50–60 minutes in a heat chamber or wearing extra layers is a serious commitment—physically and mentally. Plus, heat training demands close monitoring of core temperature, hydration, and nutrition. It’s not something you can casually squeeze in during an evening session, because replacing lost fluids before bed becomes a challenge.

For pros, the effort is justified—they’re chasing those final performance gains. For amateurs, the real question is: is the time and effort worth the potential improvement?

Heat training is particularly useful after an altitude camp. It helps extend the positive effects of altitude by keeping the body stimulated to produce red blood cells. But for the average amateur, a three-week altitude camp is a stretch.

While heat training is now standard in pro training routines, for most amateurs it remains a questionable investment. Unless you’ve just returned from altitude and want to prolong the gains, your training time is probably better spent on other proven methods.