Hartwell et al. used a prospective cohort study design to ask the question: Does running increase the risk of hip and knee arthritis? They hypothesized that the prevalence of osteoarthritis (OA) in runners was not associated with an athlete’s running-related history. This hypothesis is in direct contrast to the long-standing dogma that running is a direct cause of hip and knee OA. This study included the number of marathons completed, cumulative years running, average weekly mileage, and average running pace.

They conducted this study by issuing a survey to all participants registered for the 2019 or 2021 Chicago marathon (n = 37, 917). 3804 people participated in this study. The mean age was 43.9 years and they finished on average 9.5 marathons. hip and/or knee arthritis prevalence was 7.3%. What’s cool is that the runner characteristics for number of marathons run has a range of 1 to 664. If you lived to 100, that’s 6.6 marathons run a year!

This study determined that the risk factors for hip/knee arthritis are:
⦁ A history of hip/knee injuries or surgery
⦁ Advancing age
⦁ Family history
⦁ BMI

These factors did not predict arthritis:
⦁ Cumulative number of years running
⦁ Number of marathons finished
⦁ Weekly mileage
⦁ Mean running pace

Something I found interesting is that this study reported that despite 24.2% of participants being told by a physician to not run any more marathons, 94.2% of runners planned to run another marathon.

Below is a graph from of the prevalence of hip and knee OA, along with pain of the hip and knee with different running characteristics. Graph B stuck out to me. Pain drops precipitously along with number of marathons run.

This is the largest surveyed group of marathon runners. There was no identified association between cumulative running history and the risk for arthritis. They did not find a dose-response relationship between running history and the risk of developing either hip or knee arthritis.

Hartwell MJ, Tanenbaum JE, Chiampas G, Terry MA, Tjong VK. Does Running Increase the Risk of Hip and Knee Arthritis? A Survey of 3804 Marathon Runners. Sports Health. 2024;16(4):622-629. doi:10.1177/19417381231190876