REGIONAL DIFFERENCES IN BONE-DENSITY OF YOUNG MEN INVOLVED IN DIFFERENT EXERCISES

In this cross-sectional, retrospective study, the bone mineral content (BMC) and density (BMD) of the whole skeleton, upper limbs, lower lim bs, femoral neck and lumbar vertebrae were measured using dual photon absorptiometry and the results compared in healthy young males involve d in: weight-lifting, running, cross-training or recreational exercise s. When adjusted for body weight, the upper limb BMD was highest in th ose engaged solely in weight-lifting, (mean 1.021, SE 0.019, and 95% C I 0.981-1.061) and lowest in runners (mean 0.908, SE 0.019 and 95% CI 0.869-0.946). These differences were significant (P = 0.0004). There w ere no significant differences in upper limb BMD between weight-lifter s and cross-trained athletes and between runners and those engaged in recreational exercises. Significant differences in BMD were observed b etween weight-lifters and recreational athletes (P = 0.001) and betwee n cross-trained athletes and runners (P = 0.03). No other significant differences were observed. These data suggest that healthy, young adul t males reporting a history of intensive weightlifting had significant ly greater bone mass of the upper limb bones than those reporting a hi story of non-weight-lifting exercises. These results imply a specific versus generalized effect of mechanical load on bones of the skeleton.