Matthijs T W Veltmeijer1, Thijs M H Eijsvogels2, Dick H J Thijssen3, Maria T E Hopman4. 1. Department of Physiology, Radboud University Medical Centre, the Netherlands. 2. Department of Physiology, Radboud University Medical Centre, the Netherlands; Henry Low Heart Centre, Department of Cardiology, Hartford Hospital, USA. 3. Department of Physiology, Radboud University Medical Centre, the Netherlands; Research Institute for Sport and Exercise Science, Liverpool John Moores University, United Kingdom. 4. Department of Physiology, Radboud University Medical Centre, the Netherlands. Electronic address: Maria.Hopman@Radboudumc.nl.
Abstract
OBJECTIVES: Current knowledge about the incidence and risk factors for exertional hyperthermia (core body temperature ≥40°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°C, core body temperature increased from 37.6±0.4°C at baseline to 37.8±0.4°C after warming-up, and 39.2±0.7°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<0.01) during the warming-up compared to non-hyperthermic peers, but similar race times (p=0.46). CONCLUSIONS: 15% of the recreational runners developed exertional hyperthermia, whilst core body temperature change during the warming-up was identified as strongest predictor for core body temperature at the finish. This study emphasizes that exertional hyperthermia is a common phenomenon in recreational athletes, and can be partially predicted.
OBJECTIVES: Current knowledge about the incidence and risk factors for exertional hyperthermia (core body temperature ≥40°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°C, core body temperature increased from 37.6±0.4°C at baseline to 37.8±0.4°C after warming-up, and 39.2±0.7°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<0.01) during the warming-up compared to non-hyperthermic peers, but similar race times (p=0.46). CONCLUSIONS: 15% of the recreational runners developed exertional hyperthermia, whilst core body temperature change during the warming-up was identified as strongest predictor for core body temperature at the finish. This study emphasizes that exertional hyperthermia is a common phenomenon in recreational athletes, and can be partially predicted.
Authors: Dieter Leyk; Joachim Hoitz; Clemens Becker; Karl Jochen Glitz; Kai Nestler; Claus Piekarski Journal: Dtsch Arztebl Int Date: 2019-08-05 Impact factor: 5.594
Authors: Jeremy Joslin; Martin D Hoffman; Ian R Rogers; Chad A Asplund; William O Roberts; Benjamin D Levine Journal: Sports Med Date: 2015-04 Impact factor: 11.136