WESTPORT, CT (Reuters Health) - Aerobic exercise can increase women's bone density, and it need not be a high-impact exercise regimen, new research shows.
 
In fact, recommendations for general health--walking for about 30 minutes a day, a few days a week--is enough improve bone mass, Dr. George A. Kelley, of the MGH Institute of Health Professions in Boston, an affiliate of Massachusetts General Hospital, told Reuters Health.
 
In a review of 24 studies that examined aerobic exercise and bone mineral density in women, Dr. Kelley's team found that, on average, regular exercisers saw about a 2% bone mass gain over non-exercisers.
 
Whether the modest gain translates into a lower risk of osteoporosis and related fracture is unclear, Dr. Kelley said. However, he added, because exercise improves balance and coordination, it could also reduce older women's odds of falling.
 
Dr. Kelley presented the study findings last week in Atlanta, Georgia, at the annual meeting of the American Public Health Association.
 
Dr. Kelley's team analyzed studies that included women who were 18 years and older, the majority of whom were sedentary. In each study, some women were assigned to an aerobic exercise regimen that lasted at least 16 weeks.
 
Walking was the most common form of exercise used in the studies, Dr. Kelley said. On average, women walked about a half hour, 3 days a week.
 
Overall, women who exercised gained close to 0.4% in bone mineral density in the lumbar vertebrae, while non-exercisers saw a decrease of nearly 2%. Exercisers also had femoral increases of 1.4%, while non-exercisers recorded a loss of about 0.6%.
 
The benefits were similar among premenopausal and postmenopausal women, Dr. Kelley noted.
 
The good news from this study is that the most popular form of exercise in the US--walking--can give a lift to bone mass, according to Dr. Kelley.
 
Since strength training with weights also helps bone density, he added, the ideal exercise plan includes aerobics and weights.