REMEDY: Impact of Menstrual Status on Musculoskeletal and Hormonal Health

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The prevalence of exercise-induced menstrual dysfunction (ExMD) is high (6-79%) in active women and may result from low energy availability (EA). ExMD increases the risk for musculoskeletal injuries and is associated with hormonal imbalances. Currently, a non-pharmacological treatment does not exist for ExMD. PURPOSE: To determine if improvements in EA in endurance-trained women, using a daily Carbohydrate-Protein supplement (CHO-PRO), will restore menstrual function and improve musculoskeletal health. METHODS: Active women with menstrual dysfunction (n=8; 7 amenorrheic, 1 oligomenorrheic, age=23±3y, VO2max =49±6 ml/kg/min, body fat=22±4%) participated in a 6-mo intervention, where they consumed 325ml of CHO-PRO drink/d (360kcal/d). Menstrual status was confirmed by measuring reproductive hormones. Energy intake and expenditure were assessed at baseline (0-mo) and post-intervention (6-mo) using 7-d weighed food and physical activity records and accelerometer. Lower body strength and power, bone mineral density (BMD), and blood hormonal levels were determined. Comparisons were made using multiple linear regression, blocking on participants. RESULTS: All women resumed menses (2.6±2.2 mo to 1st menses, 3.5±1.9 cycles during intervention). Women with longer duration of ExMD took longer to resume menses. No differences were detected in BMD (p>0.05), but improvements were observed in women with low BMD at the spine. Two women had low hip BMD at 0-mo and had no change in status at 6-mo. Two women had low spine BMD at 0-mo, and one improved status to normal at 6-mo. One women had osteoporosis of the spine at 0-mo and improved status to low BMD at 6-mo. Knee extension was higher at 6-mo vs. 0-mo (p=0.002), but no other strength differences were detected (p >0.05). CONCLUSION: Increasing daily energy intake using a CHO-PRO supplement was effective in resuming menses in active women. Although all participants did resume menses, improvements in muscle strength were only observed in knee extension. Improvements in BMD were only observed in women with low BMD. More time may be required after the resumption of menses before improvements in muscle strength and BMD are realized. Supported by Gatorade Sports Science Institute.