[Evaluation of exercise as a preventive therapy for osteoporosis]

Osteoporosis and osteoporotic fractures have become an epidemic in the industrialized world. Osteoporosis, low bone mass, is a silent condition with microarchitectural deterioration of the bone structure leading to decreased bone strength and osteoporotic fractures. Physical activity has been advocated as offering a potential means to increase and maintain bone mineral density. Previous cross-sectional studies showed that there is a strong association between exercise and bone mineral density, especially in athletic individuals. However, there might be a self-selection bias; i.e. individuals with larger muscles and bones are more likely to choose an athletic lifestyle. Although there is a report that physical activity is associated with a reduced risk for hip fracture among older community-dwelling women, the effects of vigorous exercises building bone mass is modest and considerably less than bisphosphonates. The proper evaluation of exercise as a preventative therapy for osteoporosis should focus on prevention of falls or osteoporotic fractures.