ANDREOLI, A., M. MONTELEONE, M. VAN LOAN, L. PROMENZIO, U. TARANTINO, and A. DE LORENZO. Effects of different sports on bone density and muscle mass in highly trained athletes. Med. Sci. Sports Exerc., Vol. 33, No. 4, 2001, pp. 507–511. It is known that participating in sports can have a beneficial effect on bone mass. However, it is not well established which sport is more beneficial for increased bone mineral density (BMD) and appendicular muscle mass (AMM). This study investigated the effects of different high-intensity activities on BMD and AMM in highly trained athletes. Sixty-two male subjects aged 18–25 yr participated in the study. The sample included judo (J;N = 21), karate (K;N = 14), and water polo (W;N = 24) athletes who all competed at national and international level. Twelve age-matched nonathletic individuals served as the control group (C). All athletes exercised regularly for at least 3 h·d-1, 6 d·wk-1. Segmental, total BMD, and AMM were measured with a dual-energy x-ray (DXA) absorptiometry (Lunar Corp., Madison, WI). DXA analysis also includes bone mineral content (BMC) and fat and lean masses. Total BMDC was significantly lower (mean ± SD: 1.27 ± 0.06 g·cm-2, P J This cross-sectional study has shown that athletes, especially those engaged in high-impact sports, have significantly higher total BMD and AMM than controls. These results suggest that the type of sport activity may be an important factor in achieving a high peak bone mass and reducing osteoporosis risk.