Effect of repeated alternative thermal stress on the physiological and body composition characteristics of young women sporadically using sauna

Aim: The aim of this study was to determine the effect of repeated alternative thermal stress on the physiological parameters of young women sporadically used sauna. Materials and method: Twenty young women (age: 24.2±2.1 years) were exposed to four sauna sessions of 12 minutes each (temperature: 90-91°C; humidity: 14-16 %) with four 6-minute cool-down breaks including 2-minute cold water immersion (temperature: 9-11oC). Physiological characteristics were monitored before and after the 72-minute experiment. Systolic and diastolic blood pressures (systolic - SBP, diastolic - DBP), heart rate (HR), forehead temperature, and body composition were determined on each subject and dependent t-test were performed on each variable. Results: During the 72-minute experiment forehead temperature increased significantly (p<0.001). A significant decrease was observed in DBP (p=0.045), body mass (p<0.001), minerals (p=0.01), body fat mass (p=0.035), BMI (p<0.001), waist to hip ratio (p=0.042), visceral fat level (p=0.004) and obesity degree (p=0.044) during four successive 12-minute sauna sessions. Conclusions: Seventy-two minutes of alternating (hot and cold) repeated thermal stress has a significant effect on significant decrease in the values of DBP, and body composition (body mass, BMI, BFM and minerals) characteristics. Two-minute cold water immersions allow the body to cool down significantly and gives the opportunity to stay in the sauna for longer time. Long stays in the sauna can be used to reduce levels of body fat in the human body.