Abstract
The objective was to compare the efficacy of three different heat acclimation protocols
to improve exercise performance in the heat. Thirty four cyclists completed one of
three 10-day interventions 1) 50-min cycling per day in 35 °C, 2) 50-min cycling per
day wearing thermal clothing, and 3) 50-min cycling wearing thermal clothing plus
25 min hot water immersion per day. Pre- and post-intervention hemoglobin mass, intravascular
volumes and core temperature were determined at rest. Heart rate, sweat rate, blood
lactate concentration and core temperature were evaluated during 15-min submaximal
and 30-min all-out cycling performance conducted in 35.2 ± 0.1 °C and 61 ± 1% relative
humidity.
There were no significant between-group differences in any of the determined variables.
None of the interventions statistically altered any of the parameters investigated
as part of the 15-min submaximal trial. However, following the intervention period,
heat chamber, thermal clothing and thermal clothing + hot water immersion all improved
30-min all-out average power in the heat (9.5 ± 3.8%, 9.5 ± 3.6 and 9.9 ± 5.2%, respectively,
p < 0.001, F = 192.3). At termination of the 30-min all-out test, the increase in
blood lactate concentration, rate of perceived exertion and sweat rate were not different
between the three interventions.
In conclusion, daily training sessions conducted either in ambient 35 °C, while wearing
thermal clothing in temperate conditions or while wearing thermal clothing combined
with hot water immersion are equally effective for improving exercise performance
in the heat.
Keywords
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Article info
Publication history
Published online: June 11, 2021
Accepted:
June 7,
2021
Received in revised form:
May 27,
2021
Received:
October 29,
2020
Identification
Copyright
© 2021 Published by Elsevier Ltd on behalf of Sports Medicine Australia.
