The main purpose of the present study was to investigate the effect of 16 weeks of resistance training (RT) on body water in men and women. Thirty men (22.7 ± 4.4 years, 68.4 ± 9.0 kg and 174.5 ± 6.6 cm) and 34 women (22.7 ± 4.1 years, 58.8 ± 11.9 kg and 162.6 ± 6.2 cm) underwent progressive RT for 16 weeks (2 phases, 8 weeks each), 3 times per week, that consisted of 10-12 whole body exercises with 3 sets of 8-12 repetitions maximum. Total body water, TBW (intracellular water, ICW and extracellular water, ECW compartments) and skeletal muscle mass (SMM) were assessed using a spectral bioelectrical impedance device (Xitron 4200 Bioimpedance Spectrum Analyzer). TBW, ICW compartment and SMM increased significantly (P < 0.05) over time in men (+7.5%, +8.2% and +4.2%, respectively) and women (+7.6%, +11.0% +3.9%, respectively), with no sex by time interaction (P > 0.05). We conclude that progressive RT promotes an increase in body water, principally by intracellular content; however, the hydration status is not influenced by sex.
Keywords: Strength training; cellular hydration; gender; skeletal muscle.