Osteoporosis, is a clinical syndrome in which a bone mass decrement greater than that normally expected in an individual of a given age, race, and gender prevails, thus causing bones to thin, become brittle, and liable to fracture. While estrogen therapy (ET) has been applied to postmenopausal women to assist them to maintain or increase their bone density levels, or to slow down the rate at which they lose bone mass, and is effective in increasing this, ET causes more side-effects. Since ET is still being recommended in some contexts of postmenopausal health care, we presently elected to examine the body of literature detailing the effects of exercise for preventing postmenopausal bone loss to better identify whether this non-pharmacological approach can be recommended as a substitute for ET. We specifically focused on examining a less well documented body of this voluminous literature, namely the efficacy of aerobic exercises for preventing osteoporosis among postmenopausal women. This body of research indicated, that unlike ET, the effects of moderate, prolonged aerobic exercise on bone, health status, and muscle strength are generally quite positive with few side-effects. Furthermore, due to their positive effects on cognitive and muscle neurophysiology, moderate aerobic exercises may have the additional benefit of preventing falls that lead to fractures. Pending further research to substantiate these findings, we conclude clinicians can safely recommend moderate intensity aerobic exercises to their premenopausal or perimenopausal patients in order to help prevent or retard the anticipated rate of bone loss and osteoporotic fractures commonly experienced by postmenopausal women if ET is not advisable.