Exercising in the heat represents a number of challenges for an athlete, ranging from discomfort to severe health threats. This is particularly relevant this year, as we approach the summer Olympic games in Tokyo, where temperature and other ambient conditions can be severe and non-predictable. Effects of heat on the body Our bodies function best at temperatures between 35 and 39°C (1). Exercise stress can result in exercise-induced gastrointestinal syndrome, which consists in decreased integrity and function of the gastrointestinal system. This condition is worsened when our core temperature goes up to 39°C. A compromised gut can, in turn, cause other issues such as bacteria entering the bloodstream, decreased nutrient…