Energy balance and reproductive function in active women.

Athletes engaged in rigorous training programs expend large amounts of energy and require appropriate energetic compensation to maintain or improve performance. If these exercise regimens are not fueled sufficiently, a negative energy balance will likely emerge and lead to a broad spectrum of menstrual cycle disturbances and less than optimal performance. This review examines the theory and evidence surrounding energy availability and reproductive function. Implications for performance and treatment strategies are also addressed.