As an orthopaedic sports medicine physician, I am often asked if endurance sports are bad for the long term health of patients’ knees, and it is a question that I find extremely interesting. Many patients and physicians have been told that running long distances is bad for their knees. Historically, there has been concern that osteoarthritis (OA) is a “wear and tear” condition, and that running long distances can speed up the progression of cartilage loss in the knees. However, recent studies may call this way of thinking into question.
A study published in 2017 found that recreational runners had a lower prevalence of osteoarthritis than both sedentary controls and elite athletes (https://pubmed.ncbi.nlm.nih.gov/28504066/). Another study published in 2024 looked at the prevalence of hip and/or knee arthritis in marathon runners, and did not identify any association between cumulative running hours and risk of OA. In this particular cohort, a history of hip/knee injuries or surgery, advancing age, family history, and elevated body mass index (BMI) were risk factors for arthritis. (https://pubmed.ncbi.nlm.nih.gov/37555313/).
Another 2024 study looking at MRI scans of running athletes compared to sedentary controls found that the running athletes exhibited significant increases in thickness of both the femoral medial articular cartilage and the tibial medial articular cartilage. This suggests that long-term mechanical stress from running may lead to positive adaptive changes in the cartilage of certain regions in the knee. (https://pubmed.ncbi.nlm.nih.gov/39144037/).
In summary, recent evidence suggests that under the right conditions, running can actually be beneficial for cartilage in the knees- and that’s not to mention the innumerable other health benefits of running. It is important to note, of course, that if a patient already has damage to the cartilage or bone in their knees that running on an injured extremity can make it worse. It is important to weigh the risks and benefits of running long distances for each individual athlete, and to stay up-to-date on the current literature!
Links to articles cited here- I encourage you to check them out!
https://pubmed.ncbi.nlm.nih.gov/28504066
https://pubmed.ncbi.nlm.nih.gov/37555313
https://pubmed.ncbi.nlm.nih.gov/39144037
Heather Kellett, MD
February 2025