The Role of Impact Activity in Peripubertal Bone Accrual

Osteoporosis has been established as a major public health problem, primarily effecting women. The attainment of maximal peak bone mass is crucial in the prevention of osteoporosis, yet little is known about the specifics of bone accrual. Physical activity has been identified as an important modifiable factor controlling bone accrual. It is has been shown that increased activity during peri-pubertal years increase bone mineral content during adulthood. Thus, strategies designed to increase peak bone mass should target the peri-pubertal years of critical bone acquisition.

Hypothesis 1a: The amount of bone mineral accrued during the peri-pubertal years is greater in girls who engage in impact activity than in those who do not.

Hypothesis 1b: The positive effects of impact activity on bone accrual are maintained after cessation of the activity, resulting in greater bone mineral density in girls who participate in impact activity during a portion of the peri-pubertal years than in those who never participated in impact activity.