Long-term basketball playing enhances bone mass and isokinetic muscle strength

Aim: To evaluate bone mass in female basketball players and the relationship between bone mineral density (BMD) and isokinetic muscle strength. Methods: We investigated 29 female basketball players, age 21.9 +/- 9.1 years, training for about 6-8 hours per week. The reference group consisted of 22 non-active female, age 21.4 +/- 1.5 years. BMD was measured using dual-energy-X-ray absorptiometry in total body, lumbar spine, the whole femur and humerus. Isokinetic peak torque of the quadriceps and hamstring muscles were measured at 60 and 180 degrees/s. Osteocalcin (OC) and cross-linked C-telopeptide (CTX) were measured by radioimmunoassay and electrochimiluminescence, respectively. Results: Compared to the controls, the basketball group had significantly (P < 0.001) a higher BMD in the total body (11.6%), the lumbar spine (9.83%), the dominant femur (16.8%), the non-dominant femur (15.8%) and the dominant humerus (8.47%). The female basketball players had also significantly higher peak torques at both isokinetic velocities (60 and 180 degrees/s) and for both lower limbs. All muscle peak torque measured for the female basketball players were significantly correlated with correspondent leg BMD and for both velocities tested. However, no significant correlations were noted for the control group. Values of formation (OC) and resorption (CTX) markers were significantly higher in the athletic females (P < 0.01 and P < 0.05, respectively). Conclusion: Our results show clearly that practice of basketball is associated with the improvement of bone mass. In addition, the most important finding of our study is that isokinetic muscle strength seems to be correlated with correspondent BMD in female basketball players.