The influence of sauna training on the hormonal system of young women

Since there are only a few papers concerning hormonal changes in people not accustomed to sauna exposure and even less with women as the subjects, the main goal of the research was to analyze the basic responses of the hormonal system in women. Women were subjected to single and repeated thermal stress in Finnish sauna. Ten healthy female between the ages of 19-21 volunteered to participate in the experiment. All selected volunteers shared similar anthropometrical parameters. Volunteers underwent a series of seven baths in Finnish sauna. Baths were taken seven times every second day, always in the morning. Each sauna treatment lasted 30 minutes. During the sauna bath the subjects rested in a half-lying down position. Average temperature in the sauna was 80.1oC, and the relative humidity of the air was 26.6%. Significant decreases of body mass and plasma volume were observed both, after the first as well as after the last exposure to heat in sauna. However, the most pronounced changes in PV were observed after the last sauna. Increase of rectal and tympanic temperatures were milder after the last sauna compared with the first one which proves organism adaptation to high temperature of environment. Statistically significant decrease were observed in plasma TSH and T4 concentrations after the last sauna exposure, whereas more than twofold increase in hGH was observed after the first and the last sauna bath. There were a significant increases in ACTH and cortisol after each sauna bath, however the rise in cortisol concentration was less pronounced after the last sauna. Significant increases of prolactin concentration after bath sauna exposures were noted. Observed changes may be the result of acclimatization of the organism to repeated exposure to heat during sauna bath.