Effects of Post-Exercise Heat Exposure on Acute Recovery and Training-Induced Performance Adaptations: A Systematic Review.

Background: Whole-body heat exposure, such as sauna bathing or hot water immersion (HWI) has been shown to induce various physiological adaptations that can improve athletic performance. However, the effects of post-exercise heat exposure on acute recovery and promoting training-induced performance adaptations are not well understood. The aim of this systematic review was to summarise the current evidence on the effects of post-exercise heat exposure on physical performance in healthy adults.

Methods: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search for articles was conducted in December 2023 and updated in June 2025 using the PubMed, SPOLIT, Medline, and SPORTDiscus databases. Eligible studies were randomised or crossover trials comparing whole-body post-exercise heat exposure (≥ 36 °C, e.g., hot water immersion to at least sternum level, or sauna bathing) to passive or placebo recovery. The risk of bias of the included studies was assessed using the Cochrane Collaboration Risk of Bias Tool version 2. Only studies that provided results on maximal physical performance outcomes in healthy adults were included.

Results: Fourteen studies, including a total of 194 participants, met the inclusion criteria. Nine studies investigated acute effects after heat exposure and five were long-term training intervention studies. The acute studies reported uncertain results, with studies showing no effects (n = 4), beneficial (n = 4), or adverse (n = 1) effects of post-exercise heat exposure on performance recovery. The chronic studies suggested that post-exercise heating may improve running performance, at least in hot conditions. However, repeated heat exposures had no effect on cycling performance or VO₂max. The overall quality of the evidence was low to moderate. The heterogeneity of study designs, heating protocols, exercise modes, performance outcomes and recovery times precluded meta-analysis.

Conclusion: Based on the current evidence, it is not possible to draw definitive conclusions about the effects of post-exercise heat exposure on recovery and physical performance development. Additional high-quality studies are needed to determine the optimal heat exposure methods and recovery strategies for different types of training and performance outcomes.