A joint (joynt) is where two or more bones are joined together. Joints can be rigid, like the joints between the bones in your skull, or movable, like knees, hips, and shoulders. Many joints have cartilage (KAHRT-uh-lij) on the ends of the bones where they come together. Healthy cartilage helps you move by allowing bones to glide over one another. It also protects bones by preventing them from rubbing against each other.

Keeping your joints healthy will allow you to run, walk, jump, play sports, and do the other things you like to do. Physical activity, a balanced diet, avoiding injuries, and getting plenty of sleep will help you stay healthy and keep your joints healthy too.

The right kinds of exercise can improve health and fitness without hurting joints. Combined with a treatment program, exercise can add to quality of life. And it can:

• Strengthen muscles around joints.
• Help maintain bone strength.
• Increase energy.
• Make it easier to sleep well.
• Help control weight.
• Improve balance.
• Improve mood.

Bones need strong muscles for support. Not exercising weakens those supporting muscles. Weak muscles put more stress on joints.

If you haven’t exercised in a while, start slowly. Don’t push yourself too hard — that can overwork muscles and make joint pain worse.

Consider these tips:

• Keep the impact low. Low-impact exercises help keep joint stress low while you move. Examples include stationary or recumbent bicycling, elliptical trainer workouts, or exercise in the water.
• Use heat. Heat can relax joints and muscles and lessen pain before exercise. Deliver the heat with warm towels, hot packs or a shower. The temperature should be warm, not painfully hot. Use for about 20 minutes.
• Move gently. Move joints gently at first to warm up. You might begin with range-of-motion exercises for 5 to 10 minutes before you move on to strengthening or aerobic exercises.
• Go slowly. Exercise with slow and easy movements. If you feel pain, take a break. Sharp pain and pain that’s worse than the usual joint pain might mean something is wrong. Slow down if you see swelling or redness in your joints.
• Ice afterward. Use ice on your joints for up to 20 minutes as needed after activity. This is even more important if your joints are swollen.

Listen to your body. Don’t push too hard. Build up slowly. Add more and harder exercise as you get stronger.