Exercise is one of the best forms of medicine for osteoarthritis. But if the condition has left your knees achy and stiff, then it may be time to rethink your cardio workout. If you currently jog or run on a treadmill to rev up your heart and burn calories, for instance, you may be worsening the damage your knees have already sustained.
Think about switching to a low-impact exercise such as swimming, cycling or walking. Whatever you choose, be sure to include plenty of stretching exercises before and after you work out, which will improve your joints' range of motion.