[Exercise and physical activities for the prevention of osteoporotic fractures: a review of the evidence].

According that osteoporosis is the common condition in an aging society such as in Japan, much progress has been made in understanding the treatment and prevention of osteoporosis. Among potential risk factors, exercise and physical activities have been recognized as lifestyle factors that might influence the risk of osteoporosis and osteoporotic fractures. To assess the relationship between exercises including physical activities and the risk for low bone mass and osteoporosis-related fractures, a literature search over past 13 years was conducted. Accumulating evidence indicates that exercises decrease the risk for hip fractures among middle aged and older men and women. Exercises also help to maintain muscle strength, muscle volume, balance, and joint flexibility, which might prevent falls and fall-related fractures. One randomized controlled trial showed back-stretching exercise reduced the risk for vertebral fractures. The literature search also indicates that high-impact and/or weight-bearing exercise might increase the bone density in the elderly and the peak bone mass among young women, while there is no association between moderate or lower-impact exercise and bone mineral density. Future research should be required to evaluate the types and quantity of physical activity needed for the prevention of osteoporosis.