Running is not actually bad for your knees, and may in fact help
prevent osteoarthritis. Photo from the Chevron Houston Marathon 2007
"If you keep running, you'll ruin your knees!" It's hard to ignore this advice offered by well-meaning non-runners, especially when it's dispensed so often and with such earnestness. Even some well-intentioned doctors buy into the belief that running ruins your knees. Osteoarthritis is caused by the wearing down of cartilage that cushions and lubricates joints. The theory is that the pounding of running causes knee cartilage to be ground away over time. Without cartilage to lubricate and cushion the knee joint, the bones grind against each other, causing pain and a rueful regret of all those years of reckless morning jogs.
But is it true? Ask that to 74-year-old Mary Harada of Newbury, Mass who will soon be inducted into the USATF Masters Hall of Fame. At one time or another Harada has held the Masters record for every distance from 400m to 5K. After 40 years of running, her knees are still intact and she continues to run six to eight miles four times a week.
Another runner you might ask is 71-year-old Emory Duick, who arrived in Santa Monica, California on Monday after running the 2,250-mile length of Route 66. Duick ran/walked an average of over 10 miles a day for 212 consecutive days, through seven states, to cover the distance between the Chicago lakefront and the Santa Monica pier. Duick doesn't think it's the running that will get you, but sitting still. "I've seen people say all they want to do is watch TV and relax [when they retire], but then they're dead in two years," Duick told the San Bernidino Sun. "That's not right. The quality of your life is dependent on how active you are." Duick completed the challenge in order to inspire other seniors to lead more active lives.
Research suggests that despite what your friends, your coworkers, your mother, and maybe even your doctor tell you, running does not increase a person's risk of osteoarthritis in the knees. A German study published in the orthopedics journal Der Orthopade found that arthritis was rare in the knees of former elite marathon runners. Another study conducted at the Johns Hopkins school of medicine and published in 2006 in the Journal of the American Osteopath Association showed that although there was radiographic evidence of osteoarthritis in endurance athletes, long-distance runners did not report any more pain symptoms than the controls. "[I]t appears that long-distance running does not increase the risk of osteoarthritis of the knees and hips for healthy people who have no other counterindications for this kind of physical activity. Long-distance running might even have a protective effect against joint degeneration," the study concluded (boldface mine).
There is a growing body of evidence that suggests that running may actually prevent knee pain. Because the cartilage in your joints does not have its own direct blood supply, it relies on movement to supply oxygen and nutrient-bearing fluids to the cartilage. The knee movement in running works as a pump, with your body weight squishing the old fluid out of the joint with each footfall, and sucking in fresh fluid every time you bend your knee to step forward. Because of this, running can actually increase the amount of cartilage in the knee joint. A study conducted at the Australian National Health and Medical Research Council found that regular activity increased cartilage volume in the knees and was not associated with knee cartilage defects in healthy middle-aged women. Another study from the Stanford Department of Immunology/Rheumatology published in Arthritis Research & Therapy in 2005 found that seniors who exercised regularly experienced 25% less musculoskeletal pain than the sedentary controls. The study also showed that not only did runners have a lower incidence of osteoarthritis, but even those who had been runners in the past and stopped showed lower pain scores than those who had never been runners.
Another reason why running may prevent osteoarthritis is because of its role in controlling weight. Obese individuals are four times more likely to suffer from osteoarthritis because of the increased strain their weight puts on their joints with every step. "Runners do not show a higher risk of developing joint arthritis on their lower extremities. However, frequency of arthritis is significantly higher in inactive and obese persons," concluded Frohnauer, et al in their article Does Running Increase the Risk of Osteoarthritis (2006). The correlation between body mass and osteoarthritis was also observed by the Stanford researchers.
It is important for aging runners to allow more time for recovery in order to prevent injuries. Herada knows this, and taking more recovery time than she has in the past is part of her recipe for senior success. For those who already suffer from osteoarthritis, exercise may actually help relieve their symptoms or prevent further degeneration. "Moderate physical activity is recommended for people already suffering from [osteoarthritis] with the goal of increasing muscle-strength, reducing pain and preserving the range of movement in the affected joints," recommend L. Zeller and S. Sukenik in an Israeli article titled The association between sports activity and knee osteoarthritis.
The best way to avoid osteoarthritis and knee pain is to moderate weight gain and keep up with regular physical exercise. An excellent way to reach both these goals is through a regular running routine.
To learn more about how to prevent chronic running injuries, read Born to Run by Christopher McDougall.