How Training in the Heat Wrecks Your Sleep and Recovery

Deep navy graphic showing two core body temperature curves overnight, a full dip on a cool night and a blocked shallow dip on a hot night, with the headline Heat takes deep sleep first

Hot-weather training does not just make the run harder. It follows you home, and the thermal load, fluid deficit and mineral losses you bring to bed take deep sleep first, which is the stage where growth hormone fires and muscle repair runs. Here is what the research shows, and how to protect recovery through a heat block.