The effect of menstrual cycle and submaximal exercise on acute body composition estimates from bioelectrical impedance

The purpose of this study was to investigate changes in percent body fat (BF%) estimates through bioelectrical impedance analysis (BIA) before and after moderate intensity exercise during the follicular and luteal phases of the menstrual cycle. Ten healthy eumenorrheic female subjects performed 45 min of exercise during the follicular phase and during the luteal phase of their menstrual cycle. BIA estimates of BF% and total body water were examined immediately before exercise and 30 minutes after the end of exercise, without fluid replacement. The results indicated no significant effects of exercise (p = 0.170) or menstrual phase (p = 0.688) on BF%. These results suggest that neither menstrual cycle nor acute exercise needs to be considered when using BIA to estimate BF% in moderately exercising women