No Increase in Knee Osteoarthritis from Running

Running does not increase the risk for knee osteoarthritis (OA), according to a new study presented here at the meeting of the American College of Rheumatology. No increase in knee OA or knee pain was associated with habitual running in any age group in a study of over 600 individuals who reported running as a regular activity at some point in their lives.

“Controversy exists over whether habitual running is harmful or beneficial,” said lead author Grace Hsiao-Wei Lo, MD, of Baylor College of Medicine in Houston, Texas. Guidelines from the Centers for Disease Control recommend either 150 minutes weekly of moderate aerobic activity, such as brisk walking, or 75 minutes weekly of vigorous aerobic activity, such as running.

Concern over the risks of running have been partially alleviated by studies showing no increase in KO among elite runners, but the small sample sizes and unique populations in those studies have limited their applicability to the millions of recreational runners.

To address these concerns, Lo and colleagues examined subjects enrolled in the Osteoarthritis Initiative, a multicenter longitudinal observational study. They administered the Lifetime Physical Activity Questionnaire, asking about frequently performed leisure activities (defined as having been performed 10 or more times) during 4 epochs in the subject’s past: from 12 to 18 years of age, 19 to 34, 35 to 49, and age 50 or older. Those who identified running as one of their frequent activities were defined as runners during that epoch. As part of the Initiative, subjects also underwent knee radiography and pain assessment at the 48-month visit.

Of the 2,683 participants, 776 (29%) were classified as runners during at least one epoch. Runners were much more likely to be male than non-runners, and had a marginally lower body mass index.

Frequent knee pain was reported at any time in life by 42% of non-runners and 35% of runners, providing an odds ratio 0.89 favoring running (95% CI 0.81-0.98). Knee pain was also less in all individual epochs, again with odds ratios favoring running, though each with 95% confidence intervals that spanned 1.0.

There was no significant difference in the rate of radiographic osteoarthritis among the two groups at any time point. Symptomatic OA (knee pain plus radiographic OA) was significantly less common in runners over the lifespan (30% vs 23%, 95% CI 0.79-0.98), and also less common in 2 of the 4 epochs.

“Non-elite running at any time in life does not appear detrimental,” Lo concluded, and may be protective of knee pain, radiographic osteoarthritis, and symptomatic osteoarthritis.” She noted that the findings are not applicable to those with pre-existing knee OA, who were excluded from the Osteoarthritis Initiative. “However, among those without OA, running should not be discouraged over a concern of an increased risk of developing knee OA.”