Bone mineral density and dietary intake of female college gymnasts

The purposes of this study were to determine bone mineral density (BMD) of female college gymnasts (N = 26) and age- (+/- 1.0 yr), height- (+/- 5.1 cm), and weight- (+/- 2.3 kg) matched controls (N = 26) using dual energy x-ray absorptiometry and to examine the relationship of physical activity, diet, menstrual history, and BMD in these athletes. Energy expenditure, dietary intake and menstruation were assessed using standardized questionnaires. The BMD of the gymnasts were significantly (all P < 0.0001) higher than controls for the lumbar spine (L1-4), total proximal femur, femoral neck, Ward's triangle, and whole body. Mean calcium and kcal intakes for both groups were lower than the Recommended Dietary Allowances, and gymnasts had significantly lower kcal intakes than controls (P < 0.05). More gymnasts than controls (59% vs 24%) reported that their menstrual cycle had been interrupted at some point since menarche (P < 0.02). The major finding of this investigation is that the BMD of gymnasts were higher than matched controls despite the fact that gymnasts as a group had inadequate dietary calcium and a higher propensity to have an interruption of their menstrual cycle.