Effects of DHEA and Exercise on Bone Marrow Fat in Postmenopausal Women

Inclusion Criteria: * women aged 55 to 85 years * non-frail, as determined by Short Physical Performance Battery score \> 9 (0-12 scale) * 5 years or longer since menopause (defined as last menstrual period) * willing to participate in a 36-week exercise program that will start at a moderate intensity and gradually progress to a higher intensity * willing to take DHEA (50mg/d) or a placebo pill daily and remain blinded for up to 36 weeks * not performing resistance exercise training or high impact weight-bearing exercise (e.g., jogging) ≥ 2 days per week in the past 6 months * ambulatory without assistive devices * serum DHEAS \< 140 μg/dL (3.8 μmol/L) * low bone mass or moderate osteoporosis indicated by lumbar spine, total hip, or femoral neck aBMD t-scores \< -1.0 and ≥ -3.0 * refusal of standard osteoporosis treatment in women with moderate osteoporosis (BMD ≥-3.0 and ≤ -2.5) * evidence of a negative (no findings suspicious for breast cancer) mammogram within the past 12 months * planning to reside in the Denver area for the duration of the study * willing to provide evidence of completed COVID-19 vaccination * no implanted metal or electronic devices * no metallic foreign body in the eye * no "triggerfish" contact lenses * no gastric reflux device * no insulin pumps * no temporary transvenous pacing leads * no aneurysm clips * no cardiac pacemakers * no implanted cardioverter defibrillator * no magnetically-activated implant or device * no neurostimulation system * no s…