Athletic Menstrual Cycle Irregularity: Endocrine Response to Exercise and Training

In brief: Studies over the last five years show a relatively high incidence of menstrual cycle irregularity in athletes. We have attempted to analyze and report on the survey literature on athletic menstrual irregularity. The evidence shows that chronic exercise stimulates marked changes in the menstrual cycle and that profound increments can occur in the availability of sex hormones during exercise. However, it is not understood how exercise stimulates changes in the cycle. Researchers now must synthesize the exercise-induced effects on hormone concentrations.