Lifelong Impact From Weight-Bearing Exercise?

Teenagers who participate in weight-bearing activities may have stronger bones later in life, suggests a new study in the January 2009 issue of the British Journal of Sports Medicine. Japanese researchers examined the bone structure and composition of 46 postmenopausal women, who were grouped according to their sport participation levels during the physically formative adolescent years (12-18 years).

The women ranged in age from 52 to 73 and were divided into two groups: the weight-bearing sports group and the non-weight-bearing sports group. Sixteen women participated in high-impact weight-bearing activities such as tennis, volleyball and basketball, while the remaining 30 participated in non-weight-bearing activities such as swimming or did no sports at all.

Researchers assessed bone mineral content (BMC) and bone mineral density (BMD) in the lumbar-spine and femoral-neck regions of the study participants and measured their femur size and geometry. While there was no difference in BMD between the two groups, the women who had participated in weight-bearing activities displayed greater BMC than those who had not. The femoral bone area was also larger in the weight-bearing exercise group.

None of the study participants were engaged in any weight-bearing exercise during the study, suggesting that such weight-bearing activity during the adolescent years can preserve bone structure 40 years later.