The effect of high level physical activity (8.5 METs or greater) and estrogen replacement therapy upon bone mass in postmenopausal females, aged 50-68 years.

The purpose of this study was to assess the effect of physical activity (PA) and estrogen therapy (ET) upon bone mass at the 1/3 and 4 mm distal radial sites in 50 postmenopausal females. The Ss (means age = 57.4 +/- 5.4 yrs) completed: 1) activity and gynecological surveys, 2) Balke treadmill tests (85% of age determined HR), and 3) single photon absorptiometry measurements of the radius. The activity surveys and treadmill tests were used to categorize Ss into high (8.5 METs or greater, n = 27) and low (6.0 METs or less, n = 23) physical activity groups (HPA/LPA), and the gynecological surveys were used to distinguish Ss who were on estrogen therapy (n = 17) and those who had never been on estrogen therapy (n = 33). Data revealed the HPA group had significantly higher BMC (g/cm) and BMC/BW (g/cm2) at the 1/3 distal radial site than the LPA group (.834 g/cm to .721 g/cm, p less than .01; and .698 g/cm2 to .653 g/cm2, p less than .06, respectively) but were not significantly different at the 4 mm distal site. The ET group had a significantly higher bone mass than the never on ET group for BMC/BW at the 4 mm site (.907 g/cm to .809 g/cm p less than .027). It was concluded that high level physical activity (8.5 METs or greater) or estrogen therapy was helpful in reducing the risk of bone loss in postmenopausal women.