Physical activity may play an important role in maximizing bone mass during adolescence to young adulthood and may have long-lasting benefits on bone health. Because peak bone mass is thought to be attained by the end of the third decade, the early adult years may be the final opportunity for its augmentation. High-impact weight-bearing exercise during youth may provide lifelong benefits in terms of bone mineral content, structure and strength, and consequently reduce fracture risk. Weight-bearing exercise in youth affects bone, and these effects may be preserved as BMC, geometric and structural advantages even after 40 years. In order to evaluate the bone strength enhanced by the exercise and sporting activity, not only measuring the BMD by DXA but also the cross sectional geometric bone analysis may clarify the further contributions.