Reduced resting metabolic rate in athletes with menstrual disorders.

Purpose: This study investigated metabolic and nutritional determinants in association with menstrual disorders in athletes. Athletes with normal menstrual function (AN; N = 21) and athletes with menstrual disorders (AD: N = 12) participated in this study.

Methods: The quality of the menstrual cycle was judged according to salivary progesterone concentrations. Resting metabolic rate (RMR) and diet-induced thermogenesis (DIT) were measured by indirect calorimetry. Body composition, energy intake and restrained eating scores were obtained.

Results: When adjusted for body composition by ANCOVA, RMR was significantly (approximately 460 kJ, P < 0.02) lower in athletes with menstrual disorders than in athletes without menstrual disorders. The DIT and the daily energy intake of the groups did not differ. Athletes with menstrual disturbances scored significantly higher on the Restraint Eating Scale (TFEQ). Thyroid hormones (fT3 and fT4), analyzed by a competitive chemiluminescent immunoassay, were in the normal range and not different between groups.

Conclusions: The results provide evidence that restrained eating and low RMR are associated with menstrual cycle disturbances in athletes.