The discussion explores whether physical activity causes osteoarthritis and how patients should exercise once OA develops. Evidence linking lifelong activity to OA onset remains weak, with moderate activity likely protective rather than harmful. For those with established OA, most exercise—even running—is associated with better function and no clear acceleration of disease, provided pain is manageable. Emphasizing “hurt versus harm,” the conversation highlights that staying active within tolerable limits is beneficial, with programs like GLIDE and aquatic therapy offering strong support for improving symptoms and mobility.