Long-distance running alters bone anthropometry, elemental composition and mineral density of young dogs

Ten young beagle dogs were run on a treadmill for 1 year, the last 15 weeks 40 km/day. Thereafter bone anthropometric variables, elemental composition, mineral density (BMD) and serum markers of bone metabolism were analyzed and compared with matched-paired control dogs. More osteophytes developed, weight-bearing bones grew larger and BMD of axial skeleton was reduced in the trained group. Zinc and sodium accumulated in bones of the runners. Zinc correlated negatively with BMD. Serum osteocalcin and C-terminal propeptide of type I procollagen did not correlate with the observed differences in BMD. This experiment implies that intensive endurance training in adolescence may reduce the peak bone mass and alter the structural properties of bone.