Abstract
Aim: To assess the within-subject variation of thermoregulatory responses during 2 consecutive
15-km road races. Secondly, we explored whether gastrointestinal temperature (TGI) data from the first race could improve our previously established predictive model
for finish TGI in the second race.
Methods: We measured TGI before and immediately after both races in 58 participants and determined correlation
coefficients. Finish TGI in the second race was predicted using a linear regression analysis including age,
BMI, pre-race fluid intake, TGI increase between baseline and the start of the race and finish TGI in the first race.
Results: Under cool conditions (WBGT 11–12°C), TGI was comparable between both races at baseline (37.6±0.4°C vs. 37.9±0.4°C; p=0.24)
and finish (39.4±0.6°C vs. 39.4±0.6°C; p=0.83). Finish TGI correlated significantly between both races (r=0.50; p<0.001). The predictive model
(p<0.001) could predict 32.2% of the finish TGI in the second race (vs. 17.1% without
finish TGI in race 1).
Conclusion: Our findings demonstrate that the use of previously obtained thermoregulatory responses
results in higher predictability of finish core body temperatures in future races,
enabling better risk assessment for those athletes that are most likely to benefit
from preventive measures.
Key word
heatstroke - heat stress disorders - body temperature regulation - body temperature
- exercise physiology
