Run for your knees

Getty Images

One of the perennial questions runners get is 'Won’t all that running ruin your knees?' The research that exists actually tends to show that runners are no more likely, and perhaps even less likely, to get osteoarthritis than non-runners. This isn’t new - here, for example, is an article I wrote back in 2008, and many others have written similar articles.

Still, the research isn’t perfect. When you select a group of runners to study, you’re inevitably exposing yourself to the possibility of selection bias: perhaps these self-described runners are the subgroup of people who are particularly suited to run without damaging their knees. With that in mind, I was interested in an abstract from last year’s American College of Rheumatology meeting (which took place last November, but my wife just pointed out the abstract to me recently), from a research team led by Grace Lo at Baylor College of Medicine.

The data comes from a big multicentre study called the Osteoarthritis Initiative that is following thousands of patients with regular assessments, X-rays, health questionnaires and so on. What’s crucial, the authors point out, is that the subjects were recruited from the community. They’re not a special running cohort. In this particular analysis, there were 2,439 participants, average age 65, of whom 28 percent reported running at some time in their life.

The participants filled out a questionnaire that included listing the three most frequent physical activities performed at various stages of their lives (12-18, 19-34, 35-49, over 50). The researchers then looked for any links between people who reported running at various stages of life (or any or all stages) and their subsequent risk of developing knee osteoarthritis.

The results are pretty straightforward: for any combination you can think of (running when young, running when old, running throughout life, etc.), the runners were less likely to develop arthritis than non-runners, by between 16 and 29 percent. Some of this was because of the fact that runners tend to weigh less - which is, indeed, one of the benefits of running - but even when the results were adjusted to account for that difference, the runners still came out ahead.

This data still isn’t perfect, but it adds another brick to the growing pile suggesting that running will not ruin your knees. In contrast, a similar analysis of data from the same Osteoarthritis Initiative, published last year, found that acute knee injuries were associated with more rapid progression of osteoarthritis. That’s consistent with earlier studies suggesting that increased risk of knee arthritis among former athletes is pretty much entirely explained by acute injuries. If you want to save your knees, in other words, worry more about twisting them than pounding them.