Does Running Increase the Risk of Hip and Knee Arthritis? A Survey of 3804 Marathon Runners

BACKGROUND: Long-distance running is a popular form of cardiovascular exercise with many well-described health benefits, from improving heart health to the management of obesity, diabetes, and mental illness. The impact of long-distance running on joint health in recreational runners, however, remains inconclusive. HYPOTHESIS: The prevalence of osteoarthritis in runners is not associated with an athlete's running-related history, including the number of marathons completed, cumulative years of running, average weekly mileage, and average running pace. STUDY DESIGN: Prospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: A survey was distributed to all participants registered for the 2019 or 2021 Chicago marathon (n = 37,917). Surveys collected runner demographics and assessed for hip/knee pain, osteoarthritis, family history, surgical history, and running-related history. Running history included the number of marathons run, number of years running, average running pace, and average weekly mileage. The overall prevalence of osteoarthritis was identified, and a multivariable logistic regression model was used to identify variables associated with the presence of hip and/or knee osteoarthritis. RESULTS: Surveys were completed by 3804 participants (response rate of 10.0%). The mean age was 43.9 years (range, 18-83 years) and participants had completed on average 9.5 marathons (median, 5 marathons; range, 1-664 marathons). The prevalence of hip and/or knee arthritis was 7.3%. A history of hip/knee injuries or surgery, advancing age, family history, and body mass index (BMI) were risk factors for arthritis. Cumulative number of years running, number of marathons completed, weekly mileage, and mean running pace were not significant predictors for arthritis. The majority (94.2%) of runners planned to run another marathon, despite 24.2% of all participants being told by a physician to do otherwise. CONCLUSION: From this largest surveyed group of marathon runners, the most significant risk factors for developing hip or knee arthritis were age, BMI, previous injury or surgery, and family history. There was no identified association between cumulative running history and the risk for arthritis.