The primary outcome measures will be spine bone mineral density (SpBMD) and total hip bone mineral density (HipBMD) measured by dual energy X-ray absorptiometry (DXA). Secondary outcome measures will be total body bone mineral content and forearm bone mineral content. In addition, we will perform studies to characterize the mechanism of the effects of these regimens. These studies will consist of measurements of urinary bone resorption markers, serum bone formation markers, calcium excretion, calcium absorption, and application of a model developed in our laboratory to estimate and compare the magnitudes of the anabolic effects (if any) of all three interventions on SpBMD and HipBMD.