One hundred twenty postmenopausal women ( mean [ + / - SD ] age , 56 + / - 4 ) who were selected because they had low forearm bone density were enrolled in a double-blind , placebo-controlled , randomized study comparing the effects of an exercise regimen ( exercise group , n = 41 ) , exercise plus dietary calcium supplementation ( exercise-calcium group , n = 39 ) , and exercise plus continuous replacement of estrogen and progesterone ( exercise-estrogen group , n = 40 ) .
