Some researchers suspect genetics may be a factor in osteoarthritis. If so, degenerative joint disease may be an inevitable fact of life for some people. However, that does not mean one should simply accept it. Most experts believe exercise is the key to remaining arthritis-free, or to prevent the disease from progressing. Exercise and stretching effectively spread the all-important synovial fluid around joints, ensuring that cartilage receives its essential nourishment.
Swimming is probably the best exercise available.
With other forms of exercise, it is important to wear sneakers with excellent cushioning and support. Bear in mind, too, that the worst possible surface on which to exercise is cement. Because it is hard and inflexible, it does not absorb shock during exercise, instead transmitting the entire force of your feet striking the ground to the joints. Asphalt pavement is also bad, but still better than cement. The best possible surfaces on which to exercise are a dirt or an athletic track if one is available.