The effect of long-distance running upon appendicular bone mineral content.

The bone mineral content (BMC) of the os calcis was measured for a group of 20 male runners at the beginning and the end of a 9-month marathon training program. The participants had no previous running experience. The percent change in bone mineral in the runners was compared with that of a control group of male subjects of the same age range (38-68 yr). The consistent runners showed a significant increase in bone mineral over that of the controls; the increase was not significant for inconsistent runners. The data suggest that those runners with longer, more consistent distances gained more bone mineral than those with shorter, more inconsistent distances.