Light Exercise May Protect Against Osteoarthritis

From the Radiological Society of North America (RSNA) comes breaking news for all middle-aged exercisers, but particularly women. If you have risk factors for osteoarthritis such as a previous knee injury and surgery as well as a family history of osteoarthritis (with joint replacement), engaging in light exercise, such as frequent walking, may actually protect against the cartilage deterioration that is at the heart of osteoarthritis of the knee. In fact, those at risk for osteoarthritis – particularly women – may accelerate knee cartilage damage by participating in strenuous exercise such as running or tennis for more than 1 hour on more than 3 days a week. Our UCSF Radiology study also found that frequent knee-bending (such as squatting, deep knee bending and kneeling for more than 30 minutes/day) is also associated with increased risk of osteoarthritis.

Osteoarthritis affects an estimated 27 million Americans over the age of 25. For this study sponsored through the Osteoarthritis Initiative of the National Institutes of Health and performed at the University of California, San Francisco (UCSF), our researchers analyzed 132 subjects who did not have any symptoms of knee osteoarthritis, but who were at risk based on family history, previous knee injury and knee surgery as well as knee symptoms in the last 12 months. They were matched with a control group. All participants were separated into three groups based on answers to life style questions – sedentary, light exercisers, and moderate to heavy exercisers. MRI exams revealed that the light exercisers had the healthiest knee cartilage among all exercise levels. Further, the study found that women who participated in moderate to strenuous exercise had higher water content and collagen abnormalities of the knee cartilage more frequently, these changes are found in more degenerated cartilage.

If you are between 45 and 65 and are at risk of osteoarthritis – that is you had a knee injury or knee surgery, you have a family history of osteoarthritis (with knee replacement), you are at an excessive weight, or engage in frequent knee bending – what should you do?

First, maintain a healthy weight. Second, avoid risky and strenuous activities that involve heavy exertion or weight lifting, such as deep knee bends (more than 30 minutes), walking up or down many flights of stairs per day (more than 10 flights); lifting objects heavier than 25 lbs; or squatting, kneeling or deep knee bending (due to work for example) more than 30 minutes per day. Consider lower impact sports such as walking, swimming, or – at the gym – an elliptical trainer. Avoid high impact activities such as running more than 1 hour for more than 3 days/week and above all run safely, non-aggressively and avoid injury.

Once again, moderation is key and for those at risk of osteoarthritis, lighter activity is better than either no activity or heavy activity. Ask your doctor for his or her advice based on your own particular risk factors.