Exercise Training and Bone Mineral Density (original) (raw)

The effect of exercise training on total and regional bone mineral density (BMD) in postmenopausal women is reviewed. Several studies on the non-estrogenreplete postmenopausal population show 1-2% changes in regional BMD with one year of weight-bearing exercises. Studies of exercise training in the estrogenreplete postmenopausal population suggest large BMD changes. The long-term effect of exercise on the rate of loss in BMD after menopause and its effects on osteoporotic fractures is a critical area for future investigations. The focus of this article is on the effects of exercise training on regional and total bone mineral density (BMD) in postmenopausal women. Excellent review articles on physical activity and bone mineral density have been completed (Drinkwater, 1994a, 1994b; Forwood & Burr, 1993; Marcus et al., 1992; Snow-Harter & Marcus, 1991). Much less is known on the relationship of physical activity to bone fracture risk. Studies on premenopausal female adults have shown that participation in exercise programs for up to one year can increase the regional BMD from 1 to 3% (Gleeson, Protos, LeBlanc, Schneider, & Evans, 1990; Lohman et al., in press; Snow-Harter, Bouxsein, Lewis, Carter, & Marcus, 1992). While this effect is statistically significant, it is not likely to have major health benefits on the incidence of osteoporosis in the elderly. Studies are needed on how exercise programs affect the older populations, where the rate of bone mineral loss may be decreased by exercise, as well as in the adolescent population, where bone mineral development may be enhanced by exercise. Drinkwater (1994b) summarizes the status of the literature in this area as follows: "There are no prospective studies to document the effect of increased physical activity with a resultant increase in bone mass on the incidence of osteoporotic fractures" (p. 724).