structural:reformatting
Exercise-related

Exercise alone is known to hyperactivate the HPA axis, but the fact that LH pulsatility is altered in amenorrheic female athletes indicates the role of negative energy balance, rather than exercise intensity per se, in menstrual irregularities. When energy balance is maintained, exercise alone has not been indicated as a factor which leads to menstrual dysfunction; however, disturbances are common in weight-stable exercising women without extreme caloric deficiency who experience negative energy balance due to high energy expenditure. This negative energy balance, in turn, causes both a state of hypometabolism as well as hormonal and metabolic alterations. Genetic predisposition, psychological stress, and hypoleptinemia caused by low FFM may in some cases some combine with the negative energy state to inhibit the hypothalamic generation of GnRH pulses required for regular menstrual cycling, thereby causing hypoestrogenism. Additionally, in athletes with exercise-induced FHA, there have been specific associations between hypercortisolism and decreased LH pulsatility. In endurance athletes with varying menstrual status, the number of menses in the past 12 months has been found to be negatively associated with diurnal cortisol secretion. It is also possible that factors such as exercise intensity and duration as well as athletic discipline have differing effects on GnRH pulsatility; this may be especially relevant for women participating in sports that emphasize strength over leanness. However, excessive exercise can cause FHA in normal weight patients who present no abnormal metabolic or gonadotropic laboratory results. In these cases, combined hormonal contraceptive pills will not address the primary cause of menstrual cessation: inhibition of the HPO axis due to excessive exercise. Thus, behavioral modifications should be pursued.