Mitigating exertional heat illness risk and preserving performance in mass-participation endurance events: a real-world analysis of a graded cooling and fluid replacement strategy.
Li H, Cao X, Feng S. · Journal of science and medicine in sport · 2026
Objectives: Endurance athletes competing in hot-humid environments face substantial thermoregulatory strain. This study evaluated whether participation in a structured graded cooling and fluid replacement program was associated with lower post-race core body temperature and improved physiological, medical, and performance outcomes.
Design: Retrospective comparative analysis of a prospectively collected, non-randomized event-based cohort.
Methods: Records from 312 endurance athletes competing in four hot-humid events in southern China (2023-2025) were analyzed. Propensity score matching within event retained 116 matched pairs. The primary outcome was post-race core body temperature; secondary outcomes included race-time deviation, heat-related medical encounters, cortisol, and interleukin-6.
Results: Post-race core body temperature was lower with graded cooling and fluid replacement (39.1 ± 0.4°C vs 39.6 ± 0.5°C; mean difference -0.50°C, 95% confidence interval -0.62 to -0.38; P
Conclusions: Participation in the structured program was associated with lower thermal strain, fewer heat-related medical presentations, and better preservation of race performance. The
Findings: support the feasibility of organizer-delivered multimodal cooling and individualized fluid replacement in hot-humid endurance events.