The Link Between Running and Arthritis
Bad to the bones: Is arthritis from running a myth or fact of life?
Illustration by Steve Graepel
Running often gets associated with adjectives like pounding, jarring and jolting, the rap for why running is bad for your joints. Because of the repetitive impact of running, yes, even trail running, runners often assume that long-term running will eventually lead to arthritis of the knees, hips or ankles. Many hang up their running shoes when confronted by arthritis’ warning signs, assuming its onset is imminent.
First the good news: runners are no more likely to suffer arthritis than non-runners, according to a 2010 review article in the Clinical Journal of Sports Medicine. Although the rate of injury among runners is high, osteoarthritis (OA) is by no measure the sport’s most common malady.
Arthritis, or more specifically osteoarthritis, is the degeneration of the articular cartilage that forms a cushion-like layer on the ends of the bones in each joint. Its loss leaves the bone susceptible to impact. The once-smooth cartilage becomes rough and cracked while the bone, without its protective layer, produces bone spurs. The pain often associated with arthritis arises not from the loss of cartilage itself but rather from trauma to the exposed, sensitive bone.
Impact or twisting forces, muscle weakness, joint instability and a history of previous joint injury can stress this important layer of cartilage and hasten the development of osteoarthritis. Given that with each stride the legs experience forces equal to several times a runner’s bodyweight, it’s no wonder runners fear the onset of injury.
“A fear that a running injury is arthritis is often the first question I hear from injured runners,” says Dr. Anthony Luke, director of the University of California, San Francisco’s Run Safe clinic, a running wellness program that focuses on injury prevention and biomechanical analyses.
Runners at Risk?
Indeed, theoretical arthritis research has generally supported the concept that repetitive stress leads to joint degeneration. Yet for runners, in an apparent contradiction, the scientific literature does not support any link between running and an increased risk of osteoarthritis.
“For 99 percent of individuals, running does not result in any increased risk of osteoarthritis,” says Dr. Stuart Willick, an osteoarthritis researcher at the University of Utah. Several possible explanations exist for this seemingly contradictory finding. One of the more compelling findings points to evidence that running seems to have a stimulating effect on the cartilage, suggesting that it may offer protection to healthy joints. Additionally, among people who do not exercise, obesity has been linked to increased risk of osteoarthritis.
A recent review of arthritis research in the journal Physical Medicine and Rehabilitation did not find a link between running and arthritis. In fact, one study examined rates of arthritis in former collegiate swimmers and runners between two and 55 years after graduation and found equal rates of hip and knee arthritis in the two groups.
In a study conducted by the Center for Disease Control, 5000 runners and walkers over the age of 20 were followed over a 13-year period. No association was found between running and either the incidence of arthritis or its progression. As with many other studies, the progression of arthritis was associated with greater body-mass index (BMI greater than 25), older age (over 50) and a history of prior knee injuries.
It’s not only the knees of runners that appear to resist the repetitive impact of running. A 2013 study by the Lawrence Berkeley Laboratory determined that, “Whereas other exercise increased OA and hip-replacement risk, running significantly reduced risk due, in part, to running’s association with lower BMI.”
As the bulk of research has concentrated on knee and hip osteoarthritis, limited information exists about the link between running and development of osteoarthritis at the ankles or lower back.
It is comforting that running does not seem to be associated with an increased risk of knee or hip arthritis. Perhaps most encouraging, older individuals, the population most commonly connected with arthritis, who run are less prone to OA than those who don’t. “The beneficial effects of running outweigh any potential risks, including osteoarthritis,” says Dr. Willick.