Neuroendocrine mechanisms in athletes.

Athletic activity may be associated with alterations in various neuroendocrine axes depending on the state of energy availability. In addition, genetic factors and an underlying predilection for polycystic ovarian syndrome (PCOS) may predispose some athletes to develop functional hypothalamic amenorrhea earlier than other athletes. In conditions of low energy availability associated with athletic activity, changes that occur in various neuroendocrine axes are primarily adaptive, and aim to either conserve energy for the most essential functions, or allow the body to draw on its reserves to meet energy needs. These hormonal changes, however, then lead to changes in body composition and bone metabolism. Impaired bone accrual in younger athletes and low bone density in older athletes constitutes the major pathologic consequence of neuroendocrine changes associated with low energy availability. The female athlete triad of low energy availability, menstrual dysfunction, and low bone density is prevalent in certain kinds of sports and activities, particularly endurance sports, gymnastics, and ballet. It is essential to screen for this condition in athletes at every preparticipation physical and during office visits, and to put in place an effective treatment team to manage the triad early, in order to optimize outcomes.