The influence of body hydration on chosen physiological reactions to sauna training

The main aim of this work was description of body hydration on chosen physiological reaction on sauna training. The experiment was conducted on 10 healthy men age 22 years. Subjects did not used sauna earlier and were not professional athletes. In first experiment subjects did not received any drinks during sauna session. In second experiment subjects drink water warmed to body temperature according to individual needs approx. 600 ml/person, while in third session received the same amount of 4% glycerol solution . In all series subjects were on empty stomach having last meal before 2200 on the day before. Sauna session consisted from 3 repetitions (15 min.) with rests (2 min.) during which subject cooled down with water (20-22°C). The following variables were registered: Tre, HR, BWT, Hct, Hb and subjective thermal perceptions. In I experiment body mass decreased by 0.78 kg, while stayed unchanged during II and III sauna schedule. The highest increase in HR were registered in I experiment, while in II and III the tendency was similar but changes significantly smaller. Rectal temperature increased at the slowest rate in III experiment and the increase was also the smallest one. The highest plasma loss was registered in I experiment, no change was observed in second, in small increase in third experiment. The value of subjective thermal perceptions (according to Bredford scale) were smallest in third experiment. The glycerol hydration increased the level of hot environment tolerance.