Analysis of body water compartments after a short sauna bath using bioelectric impedance analysis

Studies have suggested that long-term sauna bathing may lower blood pressure in persons with hypertension by causing a direct loss of extracellular water and plasma minerals. The objective of the present study was to evaluate the effect of short-term sauna bathing on body water compartments as estimated by bioelectric impedance analysis (BIA). We recruited 15 men [mean age (+/-SD) of 23.93+/-5.12 years and mean body mass index (BMI) of 23.25+/-2.84 kg/m(2)] and 10 women matched for age and BMI. Total body resistance, reactance, and impedance were measured for all participants using BIA, at baseline, after a short sauna bath, and after a rest period. Total, extracellular, and intracellular water compartments were calculated using BIA formulae. There were no significant differences for any of the body water compartments when comparing the measurements taken before and after the sauna bath and after the rest period. However, it remains to be determined whether or not BIA is sensitive to rapid changes in water volume.