Comparative Effects of Hydrothermal Recovery Modalities on Physiological Variables in University-Level Athletes: A Randomised Controlled Trial

Background: Recovery strategies are essential for maintaining athletic performance and preventing overtraining. Hydrothermal therapies, including sauna, steam, and whirlpool baths, have gained popularity among athletes; however, their comparative physiological effects remain inadequately characterised. Objective: To compare the effects of sauna bath, steam bath, and whirlpool bath on selected physiological variables, including vital capacity, blood pressure, heart rate, oxygen saturation, and blood lactate levels in university-level male athletes. Methods: A six-week randomised controlled trial was conducted with 40 university-level male athletes (aged 18-25 years) from Banaras Hindu University. Participants were randomly assigned to four groups (n = 10 each): a sauna bath group, a steam bath group, a whirlpool bath group, and a control group. Each experimental group received three 20-minute recovery sessions weekly for six weeks following regular training. Physiological measurements were taken before and after the intervention using standardised equipment, including spirometry, oximetry, a sphygmomanometer, and lactate analysis. Results: Significant improvements were observed across multiple physiological parameters in intervention groups compared to controls. Vital capacity increased by 8.61% in the steam group, 6.97% in the sauna group, and 4.76% in the whirlpool group versus 1.27% in controls (p<0.001). Systolic blood pressure decreased significantly in the sauna (-6.15%) and steam (-4.55%) groups. Blood lactate clearance was enhanced in all intervention groups: whirlpool (-21.03%), sauna (-19.08%), and steam (-18.05%) compared to minimal change in the control group (-0.72%). Conclusions: All hydrothermal recovery modalities demonstrated significant physiological benefits compared to passive recovery. Steam and sauna therapies were most effective for improving respiratory and cardiovascular function, while whirlpool therapy demonstrated superior lactate clearance. These findings support the integration of hydrothermal recovery strategies in athletic training programs.