This proposal aims to conduct a 10-week randomized controlled trial comparing walking and resistance training with and without computerized cognitive training in older Veterans with Multiple Sclerosis, followed by 12 months of fall tracking with sensors and fall calendars. The primary objectives of this proposed CDA2 are to provide critical preliminary data on 1) the feasibility of conducting a 10-week RCT, 2) preliminary treatment effects on gait, cognition, and falls, and 3) neuroinflammatory biomarkers. Dr. Katherine Hsieh will receive hands-on training in the design and conduct of clinical trials (Dr. Hackney), mechanisms underlying physical activity, cognitive rehabilitation, and falls (Drs. Twamley, Hackney, \& Kesar), fall detection technology (Prof. Sanford), and clinical problems faced by MS participants (Dr. Backus) to achieve her long-term career goal of becoming an independent falls prevention investigator.