Effect of precooling and acclimation on repeat-sprint performance in heat

Area of Science:

• Environmental Exercise Physiology
• Sports Science
• Human Performance in Heat

Background:

• Partial heat acclimation enhances exercise performance in hot conditions.
• Precooling strategies are used to mitigate heat stress during exercise.
• The additive effect of precooling on repeat-sprint performance post-acclimation is not well-established.

Purpose of the Study:

• To investigate the additive effect of precooling on repeat-sprint cycling performance in heat following partial heat acclimation.
• To compare performance between pre-acclimation, post-acclimation, and post-acclimation with precooling conditions.

Main Methods:

• Ten males completed three cycling trials: Pre Acclimation (Pre Acc), Post Acclimation (Post Acc), and Post Acclimation with precooling (Post Acc +PC).
• Participants underwent five heat acclimation sessions between pre and post trials.
• Repeat-sprint cycling protocol was conducted in a hot environment (∼35°C, 60% RH).

Main Results:

• No significant differences in performance variables were observed between Post Acc and Post Acc +PC.
• Moderate effect sizes indicated improved work performed in Post Acc versus Pre Acc.
• Precooling (Post Acc +PC) led to significantly higher sweat loss compared to other conditions.

Conclusions:

• Partial heat acclimation improves repeat-sprint cycling performance in the heat.
• Precooling does not provide additional performance benefits when superimposed on partial heat acclimation.
• Further research may explore different precooling methods or acclimation durations.