Heat acclimation produces a real, moderate time-trial performance benefit, with 8-14 day protocols generally outperforming shorter ones
Interpretation
Mohammed Rahimi et al.'s meta-analysis of 11 RCTs found a pooled standardized mean difference of 0.50 for time-trial performance improvement following heat acclimation, with medium-term (8-14 day) protocols showing larger gains than short-term (≤7 day) ones. The underlying sample skews heavily male (91%) and relatively young (mean age 26), so apply some caution generalizing exact magnitudes to a broader age-group population.
Practical implication
Recommend an 8-14 day heat-acclimation protocol ahead of a hot-weather race where feasible, rather than a token few days, while being explicit that the supporting evidence base is still predominantly young and male.
Sources
1 source, independently verified.
JSSM 18(2):316-326. Pooled SMD of 0.50 for time-trial performance improvement after heat acclimation; medium-term protocols (8-14 days) outperformed short-term (≤7 days). No DOI could be confirmed for this journal/article after two search passes — linked via its stable PMC record instead.