Jumping improves lower limbs bone mass and lean mass in elite jumpers.

BACKGROUND: The present study was designed to examine the influence of extreme impact loading induced by jump training on bone mineral density (BMD) and bone mineral content (BMC) in high level jumpers. METHODS: Forty boys volunteered for the study aged 20 to 21 years. They were 22 high level jumpers and 18 controls. Bone mass and body composition measurements were performed by dual-energy X-ray absorptiometry, in the total body and at different sites. RESULTS: The results showed that BMC, BMD, bone area, and lean mass (P<0.0001) were significantly higher in the jumpers compared to the controls. A strong positive correlation was found between lean mass and bone parameters (BMC at the right femur, r=0.80; P<0.01). The values of the same correlation were weak in the control group. In addition, the effects of the regular practice of jumping on the BMD, BMC, and bone area were more pronounced in the lower limbs (P<0.01). These adaptations were site-specific, with increased bone mass at the lower limbs (P<0.01), especially at the legs, right and left leg (LRL) (P<0.05). It appears that the time dedicated to this activity may be account for the difference between jumpers and controls. CONCLUSIONS: The practice of high level jump starting at pubertal age generates an increase and an acquisition of the bone mass in males. This adaptation is further enhanced by the times dedicated for this activity. Therefore, it would be interesting to program jumping activities daily to conserve bone mineral and to prevent osteopenia.