Aerobic activity in prevention and symptom control of osteoarthritis.

Almost 27 million adults in the United States experience some form of osteoarthritis (OA). An epidemic of arthritis-associated disability is expected in the United States during the next 2 decades, largely fueled by the aging population and the tremendous growth in the prevalence of knee OA. Regular physical activity (PA), particularly strengthening and aerobic activity, can reduce pain and improve function and health status among patients with knee and hip OA. The focus of this review is on the impact of aerobic activity on the progression and symptom control of OA. In general, both strengthening and aerobic exercise are associated with improvements in pain, perceived physical function, and performance measures for persons with lower limb OA, although comparisons of strengthening versus aerobic exercise on these outcomes are unusual. Structural disease progression in persons with established OA has been directly evaluated by a limited number of PA clinical trials for persons with knee OA, but these protocols focused on strength training exclusively. In healthy subjects, it appears that overall PA is beneficial, rather than detrimental, to knee joint health. Possibly the most important reason for engaging in PA is to prevent obesity, which independently has been associated with many serious chronic diseases, including the incidence and progression of OA. More research is needed to determine the optimal types and dosing of aerobic conditioning.