Purpose: To determine if walking, independently of other types of physical activity, influences bone density and rates of bone loss from the lumbar spine and whole body.
Patients and methods: Healthy, white, postmenopausal women (n = 239) participating in a 1-year, placebo-controlled trial of vitamin D supplementation were studied. Bone densities of the lumbar spine and whole body were measured semiannually by dual-energy x-ray absorptiometry. Current and historical participation in outdoor walking and other leisure-time physical activities was assessed by questionnaire.
Results: Women who walk more than 7.5 miles per week had higher mean bone density of the whole body and of the legs and trunk regions of the body than women who walk less than 1 mile per week. The current level of walking activity was reflective of lifelong walking habits. The number of miles walked per week was also correlated with longitudinal rates of change in bone density at the legs (rp = 0.16, p = 0.03).
Conclusions: Healthy postmenopausal women who walk approximately 1 mile each day have higher whole-body bone density than women who walk shorter distances. Walking is also effective in slowing the rate of bone loss from the legs. These results strongly support the widely held belief that walking is a beneficial form of physical activity for maintaining skeletal integrity.