Evaluation of the Preparation of Runners and the Impact of an Ultra-trail Event in a Hot and Humid Environment

Human beings are characterized by their extraordinary ability to thermoregulate. During a physical exercise, only 25% of the energy provided by the substrates is converted into muscular mechanical work. The remaining 75% is released as heat. In fact, thermoregulation has always been an integral part of exercise's physiology. Due to current climate change, study and understand the mechanisms of thermoregulation and the practices of runners to cope with these constraints becomes increasingly necessary in order to optimize the sports performance and protect the health of athletes of all levels. Heat stroke is responsible for more deaths than any other environmental disaster and is the second leading cause of sport mortality after heart problems. The exercise-related hyperthermia and malignant hyperthermia, dehydration and hyponatremia problems have been relatively well studied in several sports. For ultra endurance disciplines, the data remains very fragmentary.