Exercise and female adolescents: effects on the reproductive and skeletal systems

It is generally accepted that exercise is beneficial for young women, since it increases cardiovascular fitness and reduces adiposity. Too much exercise can have negative effects on the reproductive and skeletal systems, however, including primary and secondary amenorrhea thought to be caused by several factors including low body weight and improper nutrition. Primary and secondary amenorrhea present similar patterns of luteinizing hormone and follicle stimulating hormone suppression, probably involving the hypothalamic-pituitary-gonadal axis and possibly also the hypothalamic-pituitary-adrenal axis. Recent research has also suggested that leptin (a hormone made by the fat cell) is a possible link between menstrual cycles and fat and energy levels. The female athletic triad consists of three interrelated problems: eating disorders, amenorrhea, and osteopenia. The most serious aspect of hypoestrogenism is its effect on bone growth of elite athletes; those with delayed menarche show a higher incidence of scoliosis, stress fractures, and osteopenia than do girls with normal menarche. The higher incidence of bone problems may be linked to a lower rate of bone accretion, which may lead to lower peak bone mass. Unfortunately, the loss may be irreversible. In addition to decreasing training and gaining weight, treatment for menarcheal delay may include oral contraceptive therapy.