One of the most recognizable traditions from my years in public school was running in the Terry Fox Run every autumn. What I hadn’t realized at that time is that the Terry Fox Run is conducted in cities across the country, even internationally! I thought this was a school thing only – oh for the days with my tiny public-school only worldview.
Apart from the developing a proper discussion about cancer awareness, research, and Terry’s incredible journey, the Terry Fox Run also gets people talking about running — who can do it, who can’t, and what about my knees? Won’t long-distance running wear down my knees? This is something I can speak to: so let’s talk running and knees.
What’s in the Running Research?
The common suggestion is that all the impact associated with running can’t be good for your knees. Blow after blow, strike after strike — it makes sense that our understanding of “wear-and-tear” breakdown would occur in our knees. However, a 2009 study out of Stanford University in the US actually started with this same hypothesis — people who run a lot will show more wear-and-tear (called “osteoarthritis”) over the long-term compared to people who don’t run as often. They then assembled a group of 113 people, 45 long-distance runners (from the Fifty-Plus Runners Association) and 53 controls (randomly selected from a lipid research clinic), and recorded the changes their knees showed by taking radiographs in 1984, 1986, 1989, 1993, 1996, and 2002. Patients had to be at least 50 years old at the beginning of the study (average age runners in 1984 = 59.8; average age “non-runners” in 1984 = 60.2), and had to receive with at least two radiographs (before dropping out) to be included in the results.
At the beginning, the running group actually did show more x-ray evidence of arthritis — 6.7% of runners compared to 0% of community controls. However, and it’s a big however, following the last radiographs taken, the runners were no more likely have knee osteoarthritis than those who didn’t run, nor were they more likely to have severe knee osteoarthritis. In fact, the study data suggests the non-runner group were showing signs of increased prevalence and severity — the exact opposite of what was expected! — though we cannot say for certain since these differences were not significantly different, which means it is possible the difference is simply random chance.
So what’s the big deal here? Runners did not show any more significant knee arthritis compared to those who don’t run. Well particularly because runners started with slightly more signs of knee osteoarthritis than the control group, this suggests that running may in fact be preventative against the progression of this type. Similarly, if you assume the runners placed more stresses and impact on their knees during the time between X-rays due to their running habits, this further suggests running might not be to blame.
These conclusions were certainly supported by other research published at the Osteoarthritis Initiative in 2014— part of the American College of Rheumatology Meetings — who reviewed data from 2439 participants in their Initiative (and they used a non-elite running sample — so more like you and me). Their results concluded that exposure to running at any time in life is not linked with higher odds of knee osteoarthritis, either on X-ray or as measured by symptoms. This remained true regardless of the age sub-category examined (12-18; 19-34; 35-49; >50). And again, looking at the raw data, there appears to be a trend towards less knee osteoarthritis in those who do run as compared to those who do not.
Overall then, while it might not be prudent at this time to suggest that running will prevent osteoarthritis in your knees, though it is a possibility that could be teased with further research, it appears that running does not influence your odds of developing knee osteoarthritis negatively.
Confused? It is a difficult topic to give firm answers on, so here are two answers: one based on research alone, and one based on research plus my clinical impression.
Final answer – complete
More research needed! I haven’t seen enough definitive data to make a concrete statement one way or the other, and this is supported by a recent Editorial piece (not yet published) in the British Journal of Sports Medicine by Leech et al., who cite factors that might unfairly influence the results of past studies — such as only using older study participants (>50 years) who by definition must have maintained their ability to run (what about people forced to stop running earlier in life due to knee pain?).
Final answer – clinical
No! Running does not appear to be detrimental to your knees. This recommendation is based on the best evidence available at this time, but may change depending on future research available.
References
- Chakravarty EF, Hubert HB, Lingala VB, Zatarain E, Fries JF. Long Distance Running and Knee Osteoarthritis: A Prospective Study. Am J Prev Med. 2009;35(2):133–8.
- Leech RD, Edwards KL, Batt ME. Does running protect against knee osteoarthritis? Or promote it? Assessing the current evidence. Br J Sports Med [Internet]. 2015;0:1–2. Available from: http://bjsm.bmj.com/lookup/doi/10.1136/bjsports-2015-094749
- Lo G, Driban J, Kriska A, et al. Habitual running any time in life is not detrimental and may be protective of symptomatic knee osteoarthritis: data from the osteoarthritis initiative [Abstract]. 2014; Abstract Number Retrieved from: http://acrabstracts.org/abstracts/habitual-running-any-time-in-life-is-not-detrimental-and-may-be-protective-of-symptomatic-knee-osteoarthritis-data-from-the-osteoarthritis-initiative/ (accessed 10 Sept 2015).