Fig. 1.

Bone health throughout the lifespan. The solid line represents the natural progression of bone mass increasing during childhood and adolescence into early adulthood, and then its natural regression of continuously decreasing into older adulthood and the elderly years, which increases the risk of osteoporosis and fragility fractures. The dashed line represents how weight-bearing physical activity creates larger increases in peak bone mass during childhood and adolescence, which leads to continuously higher bone mass into adulthood and the elderly years to reduce the risk of osteoporosis and fragility fractures.