Body composition in postpubertal boy cyclists.

Twenty-two young male cyclists aged 15 to 19 years (mean 16.2 +/- 0.4 years) were studied in order to assess the effect of physical training on the body composition of adolescents. The subjects had been training on the road 10 hours per week for over 2 years, and were compared to 22 sedentary normal subjects of similar age range (mean 16.9 +/- 0.3 years). Food and calcium intake was similar in both groups. The total body bone mineral content and total body bone mineral density were lower in the group of cyclist adolescents (p < 0.05 respectively). There were no differences in height, weight, corporal index, percent body fat, fat-free mass and soft tissue mass between groups. Our results suggest that cycling in male adolescents may be associated with a lower bone mass gain. In our opinion, the recommendable nature, quantity and quality of exercise at these ages must be better defined, through additional experimentally-designed studies, in order to prevent negative effects over bone mass gain.