Heat Acclimation Decay and Re-Induction: A Systematic Review and Meta-Analysis.

HAD and HRA differ considerably between physiological systems. Five or more HA days are sufficient to cause adaptations in HR and T c; however, extending the daily heat exposure duration enhances T c adaptations. For every decay day, ~ 2.5% of the adaptations in HR and T c are lost. For SR, longer HA periods are related to better adaptations. High heat exposure intensities seem beneficial for adaptations in SR, but not in T c. HRA induces adaptations in HR and T c at a faster rate than HA. HRA may thus provide a practical and less disruptive means of maintaining and optimizing HA prior to competition.