Effect of physical activity on bone turnover in young boys

Aims: to evaluate the effect of the physical activity on bone turnover in young male soccer players at the Tanner's stage of 1-2. Material and methods: 61 young soccer players (13,4 0,3 years old) who actively participated in soccer since 3,7 0,7 years were compared to 60 age and sex-matched non active subjects. Bone mineral density (BMD) of whole body, and in specific skeleton sites, fatty body mass (FBM) and lean body mass (LBM) were determined by a dual energy X-ray absorptiometry (DXA). Total plasma alkaline phosphatase (ALP) and plasma bone alkaline phosphatase (BALP), plasma osteocalcin (OC) and plasma collagen type I cross-linked C-telopeptide (CTX) were measured. Results: BNID of the whole body and at the lumbar spine (L2-L4), femoral, lower limbs and LBM were significantly higher in young soccer players than in controls. The biochemical markers of bone turnover: ALP (6,7%), BALP (8,9%), OC (3%) and CTX (3,1%) were not significantly higher in sportsmen than in controls. The calcium was significantly higher in sportsmen than in controls. Conclusion: these results suggest that soccer practice induced an increase of bone mass in boys. The increase in the level of bone turnover evaluated by the new biochemical markers was not significant in the sportsmen.