Abstract des Autors

Changes in protein synthesis caused by training form the basis for improved cell function. Metabolites accumulated during training act as "inductors" and determine the specific nature of adaptive protein synthesis. The role of metabolites is enhanced by hormones, and in particular testosterone increases the synthesis of myofibrillary proteins whereas thyroid hormones boost mitochondrial protein synthesis. No significant differences were observed between the two sexes in terms of hormonal response to training. Plasma testosterone levels were lower in women, but the variations were similar. No major differences in the hormonal response to training existed in relation to different stages of the menstrual cycle, although minor variations were observed during the post-ovulatory stage. No constant variations were observed in cortisolemia in women skiers undergoing strenuous training for 30 minutes at 75% VO2max during periods between days 3-4, 11-14, and 18-21 of the menstrual cycle. In non-active women the excretion of the 17-hydroxycorticoids increases following intense regular training during the menstrual period, decreases during the pre-ovulatory stage and remains constant during and after ovulation, whereas in athletes these differences are minimal. Lower levels of androgenous hormones in women serve to explain the lesser increments in strength in relation to training load. It is now well known increased strength in women depends, as in men, on the intensity and duration of resistance training due to increased muscular fibre rather than improved neurosensorial adaptation. Strength increases but is accompanied by minimum variation in fibre area. It should also be emphasised that low testosterone levels may be compensated by a high level of sensitivity to the anabolic action of testosterone. Further research is necessary to clarify the differences between the two sexes in relation to the anabolic action of androgens and the catabolic action of glucocorticoids. The interference of high estradiol levels during ovulation and high progesterone levels during the menstrual period must also be evaluated in relation to adaptive protein synthesis. According to recent research the administration of progesterone appears to annul the effects of glucocorticoids on the capacity of adrenalectomised rate to produce work. Verf.-Referat