Energy Availability, Not Body Fatness, Regulates Reproductive Function in Women

In Brief LOUCKS, A. B. Energy availability, not body fatness, regulates reproductive function in women. Exerc. Sport Sci. Rev., Vol. 31, No. 3, pp. 144–148, 2003. The morbid consequences of menstrual disorders in athletes require medical diagnosis and treatment. Reproductive disruption appears to occur when energy availability (dietary energy intake minus exercise energy expenditure) falls below a threshold between 20 and 30 kcal ·kgLBM−1·d−1, and some women may be more severely affected than others by subthreshold energy availability. Exercise appears to have no suppressive effect on menstrual function beyond the impact of its energy cost on energy availability.