Explainer · Fitness & Exercise
Is running bad for your knees? What the research shows
Running is often blamed for worn-out knees. Studies of more than 100,000 people suggest recreational runners have less hip and knee osteoarthritis than non-runners, though years of high-volume competitive running may differ.
- A 2017 review of 17 studies and 114,829 people compared hip and knee osteoarthritis in runners and non-runners.
- Arthritis affected 3.5% of recreational runners, 10.2% of non-runners and 13.3% of competitive runners.
- A US study found people who had run at some point had no more knee arthritis symptoms than those who never ran.
- Among 675 active marathon runners, 8.8% of the Americans reported arthritis, against 17.9% of a matched US group.
- The research is observational; past injuries, weight and family history also shape arthritis risk.
Running puts repeated impact through the hips and knees, and the idea that it wears joints out is one of the most familiar warnings in fitness. It seems intuitive: more pounding, more wear.
The research mostly points the other way for recreational running. Large reviews find less hip and knee osteoarthritis in recreational runners than in people who do not run. The picture is less clear for years of high-volume competitive running, and all of the evidence comes from observational studies rather than trials.
What knee and hip osteoarthritis is
Osteoarthritis is the most common form of arthritis. The smooth cartilage that cushions the ends of the bones in a joint breaks down, and the joint can become painful and stiff. A 2016 review in the American Journal of Sports Medicine describes knee osteoarthritis as a chronic condition characterized by pain, impaired function, and reduced quality of life.
The same review lists established risk factors for knee OA, including obesity, occupation, and injury, with OA standing for osteoarthritis. Age and family history matter too. Running is different: whether it adds to the risk has been genuinely unclear, which is why the question persists.
What studies show about running and arthritis
The largest summary is a 2017 review in the Journal of Orthopaedic and Sports Physical Therapy. It gathered 25 studies of 125,810 people and pooled 17 of them, covering 114,829 people, comparing hip and knee osteoarthritis in runners and in sedentary non-runners.
Osteoarthritis affected 3.5% of recreational runners, 10.2% of non-runners and 13.3% of competitive runners, defined as professional or elite athletes or people who raced internationally. Recreational runners had a lower occurrence of OA compared with competitive runners and controls, the authors wrote, with OA standing for osteoarthritis. People who had run for less than 15 years also had less arthritis than non-runners.
The authors read this as two risks at either end: a sedentary lifestyle on one side, and long exposure to high-volume or high-intensity running on the other, were both linked with hip and knee osteoarthritis. They noted that they could not tell whether these links were causal or confounded by other risk factors, such as previous injury.
What a US study of runners found in their knees
A study from the US Osteoarthritis Initiative looked at people’s knees and their lifetime running history at one point in time. About 29.5% had run at some point in their lives. Current and past runners had no more knee pain, x-ray signs of osteoarthritis or painful osteoarthritis than people who had never run, and on some measures they had less.
The authors concluded there is no increased risk of symptomatic knee OA among self-selected runners compared with non-runners. In people without osteoarthritis, they wrote, running does not appear to be detrimental to the knees.
What other running and knee reviews found
Two more reviews reach cautious conclusions from different angles. The 2016 review pooled 15 studies of running and knee osteoarthritis. Findings for a diagnosis of osteoarthritis were mixed, but runners were less likely to need surgery for it, with about half the odds of non-runners. Its authors concluded that it is not possible to determine the role of running in knee OA from the evidence available.
A 2023 review in Physical Therapy in Sport asked whether running more miles matters. Runners covering more than 48 km, about 30 miles, a week did not show clearly more knee osteoarthritis than non-runners. Its authors wrote that it is unclear whether running volume is associated with increased knee osteoarthritis prevalence, and called for large, long-term studies.
What marathon runners report about their knees
A 2018 survey in the Journal of Bone and Joint Surgery reached 675 active marathon runners who had completed at least five marathons and still ran at least 10 miles a week. On average they were 48, ran 36 miles a week, had been running for 19 years and had finished 76 marathons.
Nearly half reported hip or knee pain, but only 8.9% reported arthritis. Among the US runners, arthritis prevalence was 8.8%, against 17.9% in a matched group from the US population. Arthritis was not linked to how far, how fast or how long they had run, or how many marathons they had completed. Age, family history, and surgical history independently predicted arthritis.
What health sources say about exercise and osteoarthritis
For people who already have osteoarthritis, exercise is part of standard care rather than something to avoid. The Osteoarthritis Research Society International (OARSI) 2019 guidelines name arthritis education and structured land-based exercise programs, with or without weight management, as core treatments for knee osteoarthritis, the options recommended for nearly everyone with the condition. We covered a 2026 trial of high-impact exercise in people who already had knee osteoarthritis in a separate article.
Why the running and knee research is hard to interpret
Every study here is observational. The biggest problem is who keeps running. People whose knees hurt tend to stop, so surveys of current runners, especially long-time marathoners, are filled with people whose joints have held up. Runners also tend to be lighter, and extra weight is a known risk for osteoarthritis.
The competitive group was small and mixed, studies defined arthritis in different ways, from x-rays to self-report, and many relied on people remembering how much they had run over decades. Past injuries, which raise arthritis risk, are hard to separate from running itself.
What the running research cannot tell us yet
No trial has assigned people to run or not run for decades and then checked their joints, and none is likely to. The studies cannot say how much running is too much, whether the answer differs for people with earlier knee injuries, or how running affects people who already have osteoarthritis over the long term.
What the running evidence adds up to
Across more than 100,000 people, recreational running has not been linked to more hip and knee osteoarthritis, and runners often have less of it than non-runners. Years of high-volume competitive running may carry more risk, though the evidence is limited and could reflect injuries.
The studies cannot show cause and effect. For any one person, joint risk also depends on age, weight, past injuries and family history.
People also ask
Is knee arthritis more common in runners?
In a 2017 meta-analysis of 17 studies and 114,829 people, hip and knee osteoarthritis affected 3.5% of recreational runners, 10.2% of non-runners and 13.3% of competitive runners.
What counts as a competitive runner in these studies?
Professional or elite athletes, or people who took part in international competitions. Recreational runners ran in an amateur, nonprofessional context.
Is marathon running linked to arthritis?
In a survey of 675 active marathon runners, arthritis prevalence among the US runners was 8.8%, against 17.9% in a matched US population, and arthritis was not linked to running mileage, intensity or number of marathons. The survey could not follow runners over time.
What raises the risk of knee osteoarthritis?
Identified risk factors for knee osteoarthritis include obesity, occupation and past joint injury, alongside age and family history. In the running studies, age, family history and past surgery predicted arthritis in marathon runners, while running history did not.
Is exercise part of osteoarthritis treatment?
The OARSI 2019 guidelines list arthritis education and structured land-based exercise programs, with or without weight management, as core treatments for knee osteoarthritis. This is general information rather than medical advice.
References
- Alentorn-Geli, E., Samuelsson, K., Musahl, V., et al. The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis. Journal of Orthopaedic and Sports Physical Therapy, 2017.
- Lo, G. H., Driban, J. B., Kriska, A. M., et al. Is There an Association Between a History of Running and Symptomatic Knee Osteoarthritis? A Cross-Sectional Study From the Osteoarthritis Initiative. Arthritis Care and Research, 2017.
- Ponzio, D. Y., Syed, U. A. M., Purcell, K., et al. Low Prevalence of Hip and Knee Arthritis in Active Marathon Runners. Journal of Bone and Joint Surgery, 2018.
- Timmins, K. A., Leech, R. D., Batt, M. E., Edwards, K. L. Running and Knee Osteoarthritis: A Systematic Review and Meta-analysis. The American Journal of Sports Medicine, 2017.
- Burfield, M., Sayers, M., Buhmann, R. The association between running volume and knee osteoarthritis prevalence: A systematic review and meta-analysis. Physical Therapy in Sport, 2023.
- Bannuru, R. R., Osani, M. C., Vaysbrot, E. E., et al. OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthritis and Cartilage, 2019.