Running Isn’t Bad For Your Knees
If you've ever mentioned taking up running, chances are you've heard the familiar refrain: "Be careful, it's bad for your knees!" This belief is so widespread that many people avoid running altogether, fearing they'll damage their joints. But what if I told you that this common advice isn't supported by scientific evidence? In fact, research suggests that running might actually be good for your knees.
Does Running Damage Your Knees
The idea that running is harmful to knees stems from a simplistic understanding of joint mechanics. The thinking goes: running involves repetitive impact, impact causes wear and tear, therefore running must cause knee damage. Some runners develop knee pain so it must occur because of their running. It sounds logical on the surface, but as we'll see, the human body is much better at adapting than this reasoning gives it credit for.
The Science: What Research Actually Shows
Contrary to popular belief, studies have consistently shown that runners are not at a higher risk of developing knee osteoarthritis. In fact, a 2018 study by Lo et al. found that "running does not increase symptoms or structural progression in people with knee osteoarthritis." This finding challenges the notion that running accelerates joint degeneration.
Moreover, a comprehensive review by Miller in 2017 concluded that "runners on average do not have a high risk of developing knee osteoarthritis, even though running places very high loads on the knee joint." This seems counterintuitive at first, but it begins to make sense when we look at how cartilage responds to the stress of running.
Cartilage Adaptation: The Key to Healthy Knees
Rather than being worn down by the impact of running, knee cartilage appears to adapt and become stronger. Miller and Krupenevich's 2020 study supports what they call the "cartilage conditioning" hypothesis. They found that "running places high stresses on cartilage, and in a healthy state these stresses trigger an adaptation response that extends the fatigue-life of cartilage." Essentially running helps create the necessary stress that results in the body laying down tissue to make the knee stronger.
This adaptation isn't just theoretical. A study by Van Ginckel et al. in 2010 showed that "10 weeks of running in untrained females increased knee cartilage dGEMRIC index, an estimate of the glycosaminoglycan content that affects cartilage stiffness." In other words as we mentioned above, running actually improves the composition of knee cartilage.
Short-Term Effects vs. Long-Term Benefits
It's true that running does cause some immediate changes in the knee and without the proper recovery this can lead to pain. The stress put on the knees during running causes the cartilage to temporally change for 1-12 hours after running, but this temporary change allows for the cartilage and the muscles of the knee to get stronger helping to maintain its health long term. This is one of the reasons recovery is so crucial when it comes to running and really all movement activities.
How Running May Actually Benefit Your Knees
When we compare the effects of running on the knees to the effect of no activity on the knees running is very beneficial for knee health. Running provides the necessary stress in order to promote cartilage health in a way that being sedentary simply cannot.
Running helps to promote the process of nutrition penetrating into the cartilage of the knee as well as squeezing out the metabolic substance. This process helps maintain healthy, well-nourished cartilage.
Wait. I developed knee pain after running?!
Sometimes knee pain does occur - it is often the result of a combination of factors rather than the act of running itself. Recovery, progressive overload, and a history of past injuries are key contributors to this issue. Inadequate recovery between runs can prevent the body from properly adapting to the stress of running, leading to cumulative strain on the knees.
Similarly, if a runner increases their mileage or intensity too quickly—without allowing their muscles, tendons, and cartilage time to adapt—this progressive overload can result in pain and/or overuse injuries. Those with a history of knee injuries or biomechanical imbalances may also be more susceptible to pain, as their knees may not tolerate the repetitive impact of running as effectively. In such cases, it’s crucial to look deeper into the training regimen, adjusting the load and recovery strategies to ensure the knee has ample time to heal and strengthen.
While running is a popular choice for maintaining cardiovascular health, it's important to recognize that it is not the only effective form of exercise for improving cardiovascular health. Many alternative activities, such as cycling, swimming, or using an elliptical machine, offer similar benefits. These low-impact exercises can be particularly beneficial for individuals who are prone to knee pain or who are recovering from an injury. By varying the types of cardiovascular exercise, runners can reduce the risk of overuse injuries and continue to improve their heart health while helping to manage their training load. Ultimately, the best exercise is one that meets your health goals while also respecting your limits and needs.
However, if you want to run and keep running here are some tips.
Tips for Knee-Friendly Running
To get the benefits of running while minimizing any risks, consider these tips:
1. Gradual progression: Don't do too much too soon. Gradually increase your running distance and intensity.
2. Proper form and footwear: Ensure you have good running technique and shoes that suit your feet.
3. Incorporate recovery: Include rest days, cross-training, and pay attention to nutrition and hydration.
4. Listen to your body: If you’re feeling pain or discomfort decrease your training load that week. This can look like switching out a run for a walk, hoping in the pool for some laps or any other activity that can help speed up your recovery. If you experience persistent pain it might be time to see someone.
You're Allowed To Run
The myth that running is bad for your knees is just that - a myth. While running does place stress on the knees in the short term, research shows that it doesn't lead to increased risk of osteoarthritis or long-term cartilage damage. In fact, moderate running can actually strengthen your knee cartilage and promote joint health.
So, if you enjoy running, science suggests you can lace up your shoes without fear of damaging your knees. Just remember to progress gradually, use good technique, and give yourself adequate recovery time.
Of course, everyone's body is different, so if you have specific concerns about running and your knee health, always feel free to reach out. We can provide personalized advice based on your individual circumstances.
References
B Sun, H. (2013). Osteoarthritis – why exercise? Journal of Exercise, Sports & Orthopedics, 1(1).
Coburn, S. L., Crossley, K. M., Kemp, J. L., Warden, S. J., West, T. J., Bruder, A. M., Mentiplay, B. F., & Culvenor, A. G. (2023). Immediate and delayed effects of joint loading activities on knee and hip cartilage: A systematic review and meta-analysis. Sports Medicine - Open, 9(1).
Dong, X., Li, C., Liu, J., Huang, P., Jiang, G., Zhang, M., Zhang, W., & Zhang, X. (2021). The effect of running on knee joint cartilage: A systematic review and meta-analysis. Physical Therapy in Sport, 47, 147–155.
Esculier, J.-F., Jarrett, M., Krowchuk, N. M., Rauscher, A., Wiggermann, V., Taunton, J. E., Wilson, D. R., Gatti, A. A., & Hunt, M. A. (2019). Cartilage recovery in runners with and without knee osteoarthritis: A pilot study. The Knee, 26(5), 1049–1057.
Horga, L. M., Hirschmann, A. C., Henckel, J., Fotiadou, A., Di Laura, A., Torlasco, C., D’Silva, A., Sharma, S., Moon, J. C., & Hart, A. J. (2020). Prevalence of abnormal findings in 230 knees of asymptomatic adults using 3.0 T MRI. Skeletal Radiology, 49(7), 1099–1107.
Lo, G. H., Musa, S. M., Driban, J. B., Kriska, A. M., McAlindon, T. E., Souza, R. B., Petersen, N. J., Storti, K. L., Eaton, C. B., Hochberg, M. C., Jackson, R. D., Kwoh, C. K., Nevitt, M. C., & Suarez-Almazor, M. E. (2018). Running does not increase symptoms or structural progression in people with knee osteoarthritis: Data from the osteoarthritis initiative. Clinical Rheumatology, 37(9), 2497–2504.
Miller, R. H., & Krupenevich, R. L. (2020). Medial knee cartilage is unlikely to withstand a lifetime of running without positive adaptation: A theoretical biomechanical model of failure phenomena. PeerJ, 8.