Acute Finnish sauna heating and cold water immersion effects on cardiovascular dynamic response in normotensive women

The study aims to evaluate the acute effects of sauna heating and cold immersion on cardiovascular dynamic response in normotensive women. Twenty-eight healthy females underwent a sauna protocol comprising three consecutive 10-min exposures, each separated by a 10-min cooling interval. Blood pressure and heart rate (HR) were measured immediately after leaving the sauna room and in the last minute of the cooling period. Three acute responses after heating in the sauna and three cooling responses had a statistically significant effect on SBP (systolic blood pressure) (p < 0.001), DBP (diastolic blood pressure) (p < 0.001), and HR (p < 0.001). SBP was significantly higher in the first heating session compared to the baseline measurement, while DBP was significantly lower. HR was significantly higher in all three heating sessions compared to the baseline measurement (p < 0.001). Progression analysis revealed a decreasing trend in SBP across heating sessions, whereas no significant trend was observed during cooling sessions. DBP and HR remained stable across heating and cooling cycles. SBP shows high sensitivity to repeated sauna stress, suggesting adaptive cardiovascular effects. However, it is still a preliminary study in young, healthy women, and in the future, more longitudinal studies are needed to identify cardiovascular responses in different age and sex groups, as well as the impact of sauna cycles on individuals with coexisting cardiovascular diseases.