Exercise has really been shown over and over to be most effective for mild to moderate osteoarthritis. A walking program is used by many people because it is easy to do and doesn't require special equipment. A good pair of walking shoes and comfortable clothing are all you need.
Many communities offer walking clubs for those who don't want to walk alone. Groups may meet at the local mall each day. Some combine walking and hiking for those who prefer an outdoor experience.
If walking isn't possible but you have access to a pool, then consider a pool therapy program. The warmth and buoyancy of the water offer gravity-free exercise for painful joints.
Strengthening exercises for the quadriceps muscle may be helpful, too. The quadriceps muscle is the large four-part muscle along the front of the thigh. Resistive training exercises to improve strength have been shown effective.
Finally, some experts advise a good diet with adequate hydration. Clear liquids (especially water) may help lubricate joints.