With road racing season in full force, many runners are hitting the pavement pounding out mile after mile searching for that one last PR (personal record) to finish out 2017. As a self-described “runner”, the worst part of running is not the endless miles of challenging myself physically, it is defending my favorite form of exercise to my family, friends, and yes, even my patients. “You shouldn’t run, you will kill your knees! Don’t you know running gives you arthritis!?”

All runners have had this conversation below. I used to just smile politely and bite my tongue, but with the holiday season fast approaching I think it is time to give my fellow runners some facts to defend themselves when their family members offer up those same comments over Thanksgiving dinner.

Running and OA

First, let’s talk about the most common knee ailment in people over the age of 50, osteoarthritis (OA). Knee osteoarthritis occurs as the cartilage (meniscus) in the knee wears down over time, leading to irritation and swelling of the thigh bone (femur) and shin bone (tibia). You can also have arthritis of the kneecap (patella). If you hear people say their knee is “bone on bone,” they are likely referring to osteoarthritis.

Despite everyone saying running causes arthritis, the first five predictors for having knee arthritis are age (>50), being overweight, gender (women > men), family history of arthritis, and repetitive stress injuries, which include lifting, kneeling, and squatting (1).

Kujala, et al conducted a study on 117 former top-level athletes and found that among them, the highest prevalence of knee OA was found among weightlifters (31%), due to the high body mass index (BMI). Only 14% of runners were found to develop OA later in life. In fact, people with higher BMI, previous participation in heavy work (squatting or kneeling), and people with previous knee injuries were more likely to develop OA of the knee than runners (2). Are you still not convinced? Don’t worry, I have more. A second study followed 45 long distance runners for 18 years and compared their x-rays to a control group of non-runners. They concluded that OA was not more prevalent in runners vs. non-runners (3).

The Weight Effect

Did you know that for one pound of weight you gain, it adds an extra four pounds of pressure to your knees? Overweight women have almost four times the risk of developing knee OA and for overweight men the risk is five times greater than for people of normal weight (1). Running is an excellent form of aerobic activity which can be used for weight loss or to maintain a healthy weight. Due to the weight effect, you can almost argue running can decrease your chance of getting knee OA if you can maintain a healthy weight.

The key to avoiding any injury is to make sure you keep yourself balanced. Runners should be supplementing their running with the appropriate cross-training, strength training, core stabilization, and stretches to ensure proper body mechanics to avoid any overuse injuries. Now, I am not saying that if you run you will never have knee pain. Nor am I telling you to go out and start running if you never have before. Moral of the story is, running has not been shown to cause knee arthritis.

So runners: the next time someone tells you not to run, you can either enlighten them with the above information or smile and sprint past them!

References
1. Anderson J, Felson DT: Factors associated with osteoarthritis of the knee in the First National Health and Nutrition Examination (HANES I). Am.J.Epidemiol. 1988;128:179-189.
2. Kujala, U. M., Kettunen, J., Paananen, H., Aalto, T., Battié, M. C., Impivaara, O., Videman, T. and Sarna, S. (1995), Knee osteoarthritis in former runners, soccer players, weight lifters, and shooters. Arthritis & Rheumatism, 38: 539–546. doi:10.1002/art.1780380413
3. Chakravarty, E.F.,Hubert, H.B., Lingala, V.B., Zatarain, E. and Fries, J.F. (2008) Long Distance Running and Knee Osteoarthritis: A Prospective Study. American Journal of Preventative Medicine, 35 (2):133-138.