RESEARCH PLAN: The study will use a repeated measures, parallel group randomized design where 100 women (≥65 y) will be randomized to one of 4 groups: 1) Exercise and ibuprofen (400 mg immediately after exercise); 2) Exercise and ibuprofen placebo; 3) Placebo exercise and ibuprofen, 4) Placebo exercise and ibuprofen placebo. Women will participate in the exercise sessions 3 days per week. The intervention will be 9 months in duration. Dual energy X-ray absorptiometry (DXA) will be used to assess hip and lumbar spine areal bone mineral density, as well as geometric changes in hip structure, and whole body lean tissue (i.e. muscle) mass. Peripheral quantitative computed tomography (pQCT) and high-resolution-pQCT will allow us to investigate detailed changes in bone microarchitecture at the wrist and muscle cross-sectional area in the forearm in response to the intervention. Safety will be addressed by closely monitoring adverse events.