The human body’s response to the conditions in the sauna

Aim: The aim of this study was to determine the effect of a 15-minute bathing session in a Finnish sauna on changes in systolic and diastolic blood pressure (SBP and DBP, respectively), heart rate (HR), and body mass. The effects of grouping variables (age, sex, BMI, frequency of sauna use, history of sauna use) were taken into account in the analysis. Materials and Methods: A total of 60 women (33.6±13.1) and 42 men (33.8±12.5) aged 17 to 79 participated in one 15-minute sauna session (temperature: 90-91°C; relative humidity: 14-16%) in December 2019, in the city of Wrocław, Poland. The participants’ body mass, SBP, DBP and HR were measured before and after sauna. Body height was measured only before sauna. Results: Sauna induced significant changes in the participants’ physiological parameters. Systolic blood pressure decreased (p<0.05) in both sexes, in older participants (p<0.001) regardless of their BMI, and in participants who had rarely used sauna and had used sauna for a minimum of several years. A significant decrease in DBP (p<0.001) and HR values and a significant loss of body fluids (p<0.001) was noted in both sexes regardless of age, BMI, frequency and history of sauna use. Conclusions: A 15-minute sauna session has a beneficial effect on the circulatory system and can be incorporated into cardiovascular therapies. Regular sauna use is an important factor, and optimal results can be achieved by visiting sauna several times a week.