The effect of acute aerobic exercise on body composition determined by the hand-to-foot and foot-to-foot bioelectrical impedance method in different phases of the menstrual cycle

The aim of this study is to evaluate the effect of acute aerobic exercise on body composition determined by BIA technology in the early follicular phase (EFP), ovulation phase (OP) and luteal phase (LP) of the menstrual cycle. 17 volunteer active female athletes (age = 20.6 ± 3.5 years, menstrual cycle = 28.8±1.2 days) with a regular menstrual cycle participated in the study. Participants performed aerobic exercises at 65-70% of the reserve heart rate on a bicycle ergometer on EFP (days 2nd-5th), OP (days 13th-15th) and LP (days 21st-25th) of the menstrual cycle in random order. Phases of the menstrual cycle were confirmed by follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone hormone analyses. In each phase, body weight (BW) was measured before, after (1-3rd minutes) and 20 minutes after exercise, and body fat percentage (BFP), lean body mass (LBM) and total body water (TBW) were measured by foot-to-foot (BIAF-F) and hand-to-foot (BIAH-F) BIA, respectively. BW measured at the 20th minute after aerobic exercise is lower than PE (p<0.05), and BW measured at LP is higher than OP (p<0.05). The effect of menstrual phase and measurement (exercise) on BFP measured by both BIAF-F and BIAH-F was not found to be significant (p>0.05). The menstrual phase effect is not significant on FFM measured by either method (p>0.05). On the other hand, FFM, measured 1-3rd minutes after exercise is higher than the 20th minute in both methods (p<0.05). The effect of menstrual phase on TBW measured by both methods was found to be insignificant (p>0.05), while the effect of exercise was found to be significant (p<0.05). On the other hand, for BIAF-F, TBW at the 20th minute is significantly lower than that measured in PE and 1-3rd minutes after exercise, and it is significantly lower than that measured in PE only for BIAH-F (p<0.05). Exercise-induced changes in BW, LBM, and TBW are less than 1.0%. For all variables obtained in both methods, the menstrual phase x time (Exercise) interaction is not significant (p>0.05). The findings of this study showed that neither the menstrual cycle nor acute moderate intensity aerobic exercise has