Does daily physical exercise favorably affect the bone mass of postmenopausal women?

To investigate the effects of physical exercise on bone mass during the climacteric and menopausal period. The study group were 1123 postmenopausal Japanese women (mean: 55.4 +/- 3.7 years). Their current bone mineral density of lumbar vertebrae (L2-4) was analyzed taking the presence or absence of regular physical exercise, the type of exercise and its duration into consideration. Of the 1123 postmenopausal women, 643 (57.3%) were currently involved is some form of physical exercise on a regular basis. Bone mineral density did not differ significantly between the women exercising at present (1.035 +/- 0.08 g/cm2) and the women who had never been involved in regular physical exercise at any time in their life (1.089 +/- 0.08 g/cm2). The bone mineral density did not differ significantly in relation to the duration of physical activity (less than 6 months: 1.054 +/- 0.169 g/cm2; 6 months to 3 years: 1.049 +/- 0.128 g/cm2; over 5 years: 1.024 +/- 0.168 g/cm2). Although a majority of the postmenopausal women surveyed were involved in some form of physical activity, the practice of mild exercise at and around the time of perimenopause did not significantly increase bone mineral density.