Use it or lose it; exercise is instrumental in keeping you healthy but it also offers benefits specific to arthritis. One of the best ways to keep joints healthy is to be and stay active. Exercise keeps muscles pliable, improves bone density, and maintains integrity of tendons, ligaments, and cartilage. Most importantly, exercise will maintain the viscosity of synovial fluid within joints. Synovial fluid is a thick fluid that keeps joints lubricated and reduces friction, like our bodies own WD-40, very important for those with arthritis.