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.
Keywords
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Article info
Publication history
Published online: April 26, 2014
Accepted:
April 17,
2014
Received in revised form:
April 10,
2014
Received:
December 23,
2013
Identification
Copyright
© 2014 Sports Medicine Australia. Published by Elsevier Inc. All rights reserved.
