Abstract des Autors

The effects of aerobic training on the menstrual cycle were examined in 15 regularly menstruating, unconditioned women, aged 18 to 34 years. Subjects were randomly assigned to low intensity (LI; n=7) or high intensity (HI; n=8) groups and studied for 4 complete menstrual cycles. All subjects exercised throughout Cycles 2-4, Cycle 1 serving as the control one for each individual. The subjects exercised 4.2+/-0.5 (Group LI) or 3.8+/-0.4 (Group HI) days/week at a relative intensity of 60-70% (mean HR = 132 bpm; Group LI) or 80-90% (mean HR = 163 bpm; Group HI) Hrmax (all values are means+/-SD). Mean distance/day was alike in LI and HI groups. The daily exercise volume was also alike in both groups. VO2max increased significantly in Cycle 3 in Group HI only. Percent body fat, determined by hydrostatic weighing, decreased significantly in Cycle 3 in Group HI. Cycle length and urinary pregnanediol glucuronide (determined daily from Day 10 till the end of the cycle) did not change throughout the study for either group. Monthly transabdominal ultrasonography revealed follicular development changes in 3 out of 7 HI subjects in Cycle 4, no ultrasonographic abnormalities being detected in LI subjects. It has been suggested that exercising aerobically at a high intensity may affect ovarian follicular development but not cycle length or urinary PdG levels. Verf.-Referat