Stay at a healthy weight or lose weight if you need to. Extra weight puts a lot of stress on the large, weight-bearing joints such as the knees, the hips, and the balls of the feet. Experts estimate that every 1 lb (0.5 kg) of body weight adds about 4 lb (1.8 kg) of stress to the knee.1 This means that if you lost just 5 lb (2.3 kg), you could take 20 lb (9.1 kg) of stress off your knees.
Be activeBe active. A lack of exercise can cause your muscles and joints to become weak. But light to moderate exercise can help keep your muscles strong and reduce joint pain and stiffness. For example, if your quadriceps (the muscles in the front of your thigh) are weak, you may be more likely to get arthritis of the knee.
Protect your joints. Try not to do tasks that cause pain or swelling in joints. And try to use the largest joints or strongest muscles to do things. A single major injury to a joint or several minor injuries can damage cartilage over time.