Abstract

We have investigated the effect of a 3-month endurance training program (running and cycling) on plasma hormone responses during standardized bicycle ergometer work (15-min consecutive work loads of 60, 70, 80, and eventually 90 VO2max) in eight previously untrained eumenorrheic women. The subjects were investigated before and after training both in the follicular and luteal phases of the menstrual cycle (between the 7th-10th and 20th-25th days of their menstrual cycle, respectively). Blood was obtained 15 and 2 min before the onset of exercise and at the end of each work load from an indwelling catheter. In each sample, the plasma concentrations of estradiol 17beta (E2), progesterone, testosterone (T), androstenedione, dehydroepiandrosterone sulfate(DHEA-S), prolactin, and adrenocorticotropic hormone (ACTH) were assayed in duplicate by RIA; lactate was assayed as well. The hormone concentrations were expressed in absolute as well as in relative values. After training basal DHEA-S and ACTH levels were significantly lower in both phases of the menstrual cycle, whereas basal luteal phase E2 and T levels were significantly lower after training. Exercise induced significant increments in the relative values of all hormones in both phases. After training, T and DHEA-S increased relatively more pronounced in the follicular and luteal phase, respectively. Verf.-Referat