Premenarcheal gymnasts possess higher bone mineral density than controls

Purpose: The purpose of this study was to examine bone mineral density (BMD ), body composition, dietary intake, physical activity, and energy expendit ure (EE) in premenarcheal gymnasts (N = 16; age = 10.5 +/- 1.5 yr) in compa rison to age- (+/- 0.35 yr), height- (+/- 2.6 cm), and weight- (+/- 1.5 kg) matched controls (N = 16; age = 10.5 +/- 1.3 yr). It was hypothesized that premenarcheal gymnasts would have higher BMD, fat-free soft tissue (FFST) mass, physical activity, and EE, but lower fat mass, percent body fat, and dietary intake than controls. Methods: Dual energy x-ray absorptiometry was used to measure whole body, femur, and lumbar spine (L1-4) BMD, FFST, and fat mass. Three-day diet records were used to estimate mean daily dietary e nergy, macronutrient, and calcium intakes. Physical activity and EE were es timated by the Seven-Day Physical Activity Recall. Results: The BMD means o f the gymnasts were significantly higher (P < 0.05) than controls at all si res, except whole body, as were lumbar spine and femoral neck bone mineral apparent densities, despite lower protein intake expressed per kg FFST mass . Fat mass was significantly lower in gymnasts versus controls (P < 0.01) a s was percent body far (P < 0.001). Very hard physical activity during week days (P < 0.0001) and estimated EE (P < 0.01) were significantly higher in gymnasts compared with controls. Conclusion: Premenarcheal gymnasts have hi gher BMD than age-, height-, and weight-matched controls.