Activity-associated differences in bone mineral are evident before puberty: A cross-sectional study of 130 female novice dancers and controls

It is not clear at what age or maturational stage physical activity is most effective in optimizing peak bone mass in girls. We compared bone mineral of 78 pre- and early-pubertal novice female ballet dancers (mean age, 9.6 years, SD, 0.8) with that of 52 age-matched controls. Dancers had 4.5% greater total hip bone mineral density (BMD) and 4.9% greater femoral neck BMD (both p <.01) than controls. BMD at the lumbar spine and upper and lower limbs was similar between groups. These findings could not be explained by maturity, size, body composition, or dietary calcium intake differences between groups. While genetics may partially explain these findings, we propose that the mechanical loading of dance training provided appropriate skeletal stimulus to generate site-specific BMD advantage.