Are Olympic athletes at greater risk for developing osteoarthritis?
As I have stressed in previous blogs, as I emphasize in my book, The Arthritis Handbook: Improve Your Health and Manage the Pain of Osteoarthritis (Diamedica, 2008), and as I tell my patients every day, joints need movement and exercise to stay healthy. Without exercise, joints start to degenerate. Study after study indicates that exercise prevents osteoarthritis from occurring, and helps treat it if it has occurred.
Exercise has other important benefits for the joints as well. Exercise, for example, strengthens the muscles around the joints, which allows those muscles to take the pressure off the joints. But, can there be too much of a good thing?
How Our Bodies Care For Our Joints
Joints do not have a direct blood supply. If they did have blood flowing through them, then each time they were twisted, banged, or otherwise stressed, they might bleed. Bleeding into the joint, even if there were an easy way for the blood to flow out of the joint (which there is not), would result in the development of scar tissue within the joint. This scar tissue would lead to chronic pain and immobility. Because there is no blood supply into the joint itself, the joint capsule receives a limited blood supply. The structures within the joint receive their nourishment and have their waste products taken away by the process of diffusion between the blood supply within the capsule of the joint and the synovial fluid within the joint. This communication between the two fluids allows for waste products built up within the joint to exit into the blood stream outside the joint, and it allows for important nutrients within the blood stream to make their way into the joint.
In a resting joint, the synovial fluid remains inside of the cartilage within the joint. As the joint is stressed and made to weight-bear, the cartilage is squeezed and the fluid exits the cartilage--just as water rushes out of a sponge that is squeezed. This action allows the synovial fluid to bathe, lubricate, and cushion the joint while it is being used--and it also allows the fluid to exchange waste products for nutrients with the blood supply within the outer capsule.
Muscle Strength and Conditioning May Balance Joint Wear and Tear
As we all know, Olympic athletes are truly amazing individuals. Their physical prowess is something to marvel at; their dedication, hard work, courage, and determination make them excellent role models. However, when the lights fade, the dust settles, and the years pass, does the repetitive stress that Olympic athletes put their bodies through day in and day out place them at greater risk for osteoarthritis as they advance in years?
As a group, athletes do tend to show more "wear-and-tear" radiographic signs of osteoarthritis within their joints. However, if you have read my book or other blogs, you know that radiographic signs do not necessarily correlate with clinical symptoms. That means that someone with severely arthritic knees on x-ray might have no pain, while someone with normal looking knees on x-ray might have a lot of pain. In the end analysis, there have not been any studies specifically looking at the development of osteoarthritis in Olympic athletes in a variety of sports. It seems reasonable to hypothesize that as a group they would show more arthritic changes in their joints on x-ray years after stopping their sport.
However -- and this is critical -- remember that Olympic athletes also have superbly trained and balanced muscles. These muscles help take the pressure and stress off the joints, and help keep those joints symptom free. If an Olympic athlete stays in shape after they are done competing, it is very likely he or she would also remain pain-free. If, however, he or she takes a long-deserved break from exercising and does not return to keeping their body in shape, they may very well have a price to pay down the line for such devotion to their sport.
Of course, another way an Olympic athlete may end up with an increased risk of osteoarthritis is through injuries. Each injury to a joint (torn ligament, meniscus, sprained ankle), puts that joint at increased risk of osteoarthritis later in life. Here, again, though, the Olympic athlete's strength and conditioning, if maintained, will help offset that risk.
What can we learn from all this, and how do we apply it to our own lives?
While it is true that repetitive stresses on the joints through sports may create some wear and tear in the joints, the benefits of exercise far out weigh the downside. The plain truth is that everyday life -- climbing stairs, sitting in cars, walking on concrete -- can be hard on our joints. By keeping our muscles strong and flexible, everyday activities are no longer difficult for our joints to face. The scale tilts heavily towards exercise being beneficial. If you want to exercise, and are planning to exercise a lot, but are concerned about creating damage to the joints in the long run, (after consulting a doctor to make sure it is safe for you to exercise) pick an activity that does not include pounding the joints. Running for example, over time, can be hard on the knees and hips. However, running on an elliptical machine does not include the pounding and is easier on the joints. Swimming is another good activity that is generally well tolerated by joints.
Of course, in addition to being good for the muscles supporting the joints, being active has benefits for the heart, mind, lungs, and general sense of well-being. Again, talk to your doctor to make sure it is safe for you to start a new exercise before beginning.