Incidence and predictors of exertional hyperthermia after a 15-km road race in cool environmental conditions.

Item does not contain fulltextOBJECTIVES: Current knowledge about the incidence and risk factors for exertional hyperthermia (core body temperature >/=40 degrees C) is predominantly based on military populations or small-sized studies in athletes. We assessed the incidence of exertional hyperthermia in 227 participants of a 15-km running race, and identified predictors for exertional hyperthermia. DESIGN: Observational study. METHODS: We measured intestinal core body temperature before and immediately after the race. To identify predictive factors of maximum core body temperature, we entered sex, age, BMI, post-finish dehydration, number of training weeks, fluid intake before and during the race, finish time, and core body temperature change during warming-up into a backward linear regression analysis. Additionally, two subgroups of hyperthermic and non-hyperthermic participants were compared. RESULTS: In a WBGT of 11 degrees C, core body temperature increased from 37.6+/-0.4 degrees C at baseline to 37.8+/-0.4 degrees C after warming-up, and 39.2+/-0.7 degrees C at the finish. A total of 15% of all participants had exertional hyperthermia at the finish. Age, BMI, fluid intake before the race and the core body temperature change during warming-up significantly predicted maximal core body temperature (p<0.001). Participants with hyperthermia at the finish line had a significantly greater core body temperature rise (p