[Do endurance sports lead to osteoporosis in women?].

Numerous studies show that (high) performance sport may reduce the ovarian function by disturbing the distribution of the hormones at the level of the hypothalamic-pituitary axis. Before puberty a delay in sexual maturity (in particular delayed menarche) and after menarche oligomenorrhoea or secondary amenorrhoea may result, most frequently in aerobic-type activities associated with lower body weight such as running, aerobics and gymnastics. Body composition and specificity of sport, intensity of training, previous menstrual history and eating disorders are all important factors. After stopping with performance sport, the regular menstrual cycle will return, but the chronic lack of oestrogen may reduce bone density and increase the prevalence of stress fractures. In conclusion, female performance athletes require medical facts about training and nutrition and individual information and guiding if a long-term hormone substitution is needed.