BY MICHAEL ROIZEN, M.D., AND MEHMET OZ, M.D.

If your knees bother you when you bend 'em, try these pill-free pain beaters:

Get strong quads. Strengthening these key leg muscles in the front of the thigh can help you maintain cartilage, because your muscles act as shock absorbers. Strong quads have been shown to protect against cartilage loss at a certain area of the knee (lateral compartment of the patellofemoral joint). Even if cartilage vanished in other parts of the knee, people with the strongest quads have still reported less knee pain and better physical function than people with the weakest. Don't wait to strengthen: More than half the people with cartilage breakdown are under age 65.

Take a hike. Or a walk. People who pick up their feet and commit to regular aerobic exercise have much less muscle and joint pain as they age. Even better, pick up the pace. Vigorous activities like running, swimming and brisk walking anything that boosts your heart rate and makes it slightly difficult to talk could increase the amount of cartilage in your knees. The caveat: "Vigorous exercise" equals "good for the knees." "Vigorous exercise that causes a joint injury" equals "really bad for the knees." Don't overdo it.

Fill up. Berries, ginger, avocado, flaxseeds, omega-3-rich fish (trout and salmon in North America) or the algae where the fish get their omega-3s from (you'd get it in the form of a DHA supplement), all help stifle joint-damaging inflammation.

The YOU Docs, Mehmet Oz and Mike Roizen, are authors of "YOU: The Owner's Manual." Want more? See "The Dr. Oz Show" on TV (check local listings). To submit questions, go to www.RealAge.com.