“Isn’t running bad for your knees?” If you’ve been a runner for more than five minutes, there’s a good chance someone has asked you this. The idea seems logical enough: running involves thousands of steps, each step loads the knee, so all that pounding must eventually wear the joint out.
Fortunately, knees are a little more sophisticated than car tires.
Current research does not support the idea that recreational running causes knee osteoarthritis or simply wears away knee cartilage. Your joints are living tissues that respond and adapt to load.
That doesn’t mean every runner should ignore knee pain and keep running regardless. Training load, previous injuries, recovery, strength, and your individual health history still matter.
Running With Knee Osteoarthritis
I was diagnosed with Grade IV knee osteoarthritis at age 21. I’ve since had two surgeries on my left knee and one on my right. I will likely need a knee replacement at some point.
So when I talk to runners who are worried that running is destroying their knees, I’m certainly not coming at this from a place of having pristine joints. I also don’t believe the answer is to become afraid of loading them.
My own history does not mean everyone with osteoarthritis should run, or that every painful knee should be pushed through. It does mean I understand how unsettling it can be to receive a diagnosis and wonder what you’re still “allowed” to do.
Rather than asking “Is running bad for my knees?” The better question is “Can my knees currently tolerate the amount and type of running I’m asking them to do?”
Does Running Cause Knee Osteoarthritis?
For recreational runners, the evidence is reassuring.
A 2023 systematic review that included more than 14,000 runners and non-runners found that running was not associated with worsening radiographic signs of knee osteoarthritis or poorer patient-reported outcomes over the periods studied. In fact, knee pain was more common among the non-running participants.
Another 2023 systematic review and meta-analysis examined running volume. Researchers did not find a higher prevalence of knee osteoarthritis among runners compared with controls, including runners covering more than 48 kilometres per week.
The same pattern has been seen among people who run a lot. In a study of 675 active marathon runners, arthritis prevalence was lower than in a matched U.S. population. The researchers found no association between arthritis and weekly mileage, running intensity, years of running, or number of marathons completed. Age, family history, and previous surgery were more strongly associated with arthritis than running history.
It’s important for me to note here that this doesn’t prove marathon running prevents arthritis. Active marathon runners are also a selected group of people healthy enough to continue running. It does, however, add to the evidence that accumulating running kilometres is not the simple cause-and-effect relationship with arthritis that many runners have been led to believe.
But What About All That Impact on Your Cartilage?
Running absolutely loads your knee cartilage, and that’s a normal part of what the joint is designed to handle.
Researchers using MRI have found small changes in knee cartilage immediately after running, including temporary reductions in cartilage thickness and volume. A systematic review and meta-analysis found that these immediate changes were transient and likely reflected normal fluid movement within the tissue. Cartilage generally recovered well after a single bout of running, repeated exposure produced limited changes, and moderate evidence suggested that running did not create new cartilage lesions.
Research involving first-time marathon runners adds another interesting piece to the picture. Before they even started marathon training, many middle-aged participants already had asymptomatic abnormalities on MRI. After training and completing the marathon, some MRI findings worsened, while signs of damage in parts of the subchondral bone actually improved.
In this study, MRI findings changed in different ways across different knee structures. Some findings improved, while others worsened, which makes the overall picture more nuanced than simple progressive joint damage from marathon training.
There is also a plausible biological explanation for why runners can tolerate repeated loading over many years. A biomechanical modelling study suggested that medial knee cartilage would be unlikely to withstand decades of running unless some positive adaptation to mechanical stress occurred. This was a theoretical model, so it doesn’t prove exactly how cartilage adapts in runners. But it supports the broader idea that cartilage is living, responsive tissue rather than an inert surface that simply wears away.
This is one reason I don’t like describing running as simple “wear and tear.” The body can adapt to appropriately progressed stress.
Why Can Running Still Make Your Knees Hurt?
Running may not automatically cause osteoarthritis, but runners can absolutely experience knee pain. Patellofemoral pain, often called runner’s knee, is one of the more common running-related complaints.
Pain can show up when the amount of stress being applied exceeds what your tissues are currently prepared to tolerate. That balance can change when training volume increases, more hills or speed work are added, recovery drops, or you return to running after time off.
Sometimes several changes happen at once. You may be running more, sleeping less, dealing with more work stress, and skipping strength training, all within the same few weeks.
This is why knee pain rarely gets solved by asking whether running itself is “good” or “bad.” It’s often more valuable to look at the relationship between load and current capacity.
Think About What Has Changed
If your knee has recently started bothering you, consider:
- Has your weekly running volume changed?
- Have you added speed sessions, hills, trails, or longer runs?
- Did you recently return after a break?
- Has your strength training dropped off?
- Are you recovering well between harder sessions?
- Did you change shoes or dramatically change your running environment?
- Is another sport or activity adding more lower-body load than usual?
Sometimes the relevant change is fairly obvious once you step back and look at the whole training picture.
High Forces Don’t Automatically Mean Joint Damage
The knee does experience substantial forces when you run, particularly at the patellofemoral joint behind the kneecap. A systematic review found that patellofemoral joint reaction forces during running are considerably higher than during walking.
That can sound alarming when those forces are expressed as multiples of body weight, but high force on its own does not mean injury or damage. Your muscles, tendons, bones, and joints routinely manage large forces during exercise and daily life.
The relevant question is whether the tissues are prepared for the amount of load being applied. A runner who has gradually built their training over several years is in a very different situation from someone who suddenly doubles their mileage or adds several hard sessions at once.
Does Strength Training Help Runners With Knee Pain or Osteoarthritis?
If you’ve been here awhile you know I’m going to bring strength training up. Research in people with knee osteoarthritis supports exercise as a safe and useful management strategy, and both strengthening and aerobic exercise have been associated with improvements in pain and physical function.
For runners, strength training can also build the muscular capacity required to tolerate the forces involved in running. I’m not suggesting you need to spend 6 days a week in the gym either; for most busy runners 2-3 days a week is great.
Your quads, calves, hamstrings, and hips all contribute to how you produce and absorb force while running. Progressive strength training gives those tissues a reason to adapt.
Can You Run If You Already Have Knee Osteoarthritis?
An osteoarthritis diagnosis does not automatically mean your running days are over.
Research examining exercise in people with established knee osteoarthritis has found that appropriately prescribed joint-loading exercise doesn’t appear to harm articular cartilage. Exercise is also widely used to improve strength, pain, and function in people living with knee OA.
We’re also starting to see research specifically involving runners who already have knee osteoarthritis. A 2026 study compared experienced older runners with and without knee OA using MRI. Although there were some regional differences in cartilage structure and composition, the researchers did not find evidence of widespread cartilage degeneration in the runners with osteoarthritis.
That doesn’t tell us what will happen to every runner over decades, but it is reassuring evidence that an OA diagnosis and continued running are not automatically incompatible.
Whether running belongs in your program is still individual. Someone who has been running consistently with stable symptoms is in a different situation from someone attempting to return after surgery, a major injury, or a long period of inactivity.
Your symptoms, training history, function, and goals all deserve consideration. You also don’t have to choose between “run normally” and “stop running completely.” Adjusting duration, frequency, intensity, or terrain may allow you to keep running while reducing the total stress on an irritated knee.
When Should You Get Knee Pain Assessed?
A mild ache after an unusually hard training week doesn’t necessarily require a full investigation. However, persistent or worsening symptoms deserve more attention.
Consider getting assessed if:
- knee pain keeps returning when you run
- pain is progressively getting worse
- swelling is significant or persistent
- your knee locks or repeatedly gives way
- you’ve changed your training but symptoms aren’t settling
- you’re returning to running after an injury or surgery
- you’re unsure how much running your knee can currently tolerate
A physiotherapist can assess your symptoms, help rule out more serious issues, and guide an appropriate return to running or activity.
So, Is Running Bad for Your Knees?
For most recreational runners, the research gives us good reason to stop treating running as a fast track to knee osteoarthritis. Running does load your knees, but loading a joint is not the same thing as damaging it.
Your ability to tolerate running can change over time, and tissues such as muscle, bone, and cartilage respond to the loads you place on them.
If your knees feel good and your training is progressing sensibly, you probably don’t need to stop running because someone warned you that you’ll “pay for it later.”
If your knees do hurt, the answer is not automatically to give up running forever. It may mean adjusting the load, building capacity, and figuring out what your knees can currently tolerate.
My knees have a fairly impressive medical resume, and I’m still a runner.
Key takeaways
- Recreational running has not been shown to increase the prevalence of knee osteoarthritis compared with not running.
- Studies of active marathon runners have not found a clear relationship between arthritis and weekly mileage, years of running, running intensity, or number of marathons completed.
- Running temporarily changes knee cartilage, but research suggests these changes are small and largely recover after exercise.
- MRI research does not show a simple pattern of progressive knee damage with marathon training.
- Knee pain in runners does not automatically mean cartilage damage or osteoarthritis.
- Sudden changes in training load can exceed your current capacity and contribute to knee pain symptoms.
- Progressive strength training can help build the physical capacity required for running and is also commonly recommended for people with knee osteoarthritis.
- Having knee osteoarthritis does not automatically mean you have to stop running. Individual symptoms, history, and function matter.
Get More Support With Your Running
If you’ve struggled with knee pain in the past, or if you’ve been cleared to run again after injury, a running assessment can help identify how your training, strength, and running mechanics fit together.
If fitting strength work around your running is the part you struggle with, you can learn more about my strength programs for runners here.
Frequently Asked Questions About Running and Knee Health
For most recreational runners, no. Current research does not show that recreational running increases the prevalence of knee osteoarthritis. Your knees are exposed to load while running, but healthy tissues can adapt to appropriately progressed training.
Research has not established recreational running as a cause of knee osteoarthritis. Several systematic reviews have found similar or lower rates of knee OA and knee pain among recreational runners compared with non-runners. Research involving active marathon runners has also failed to find a clear relationship between arthritis and weekly mileage, running intensity, years of running, or number of marathons completed.
Running can cause temporary changes in cartilage thickness, volume, and fluid content immediately after exercise. Research suggests these changes largely recover and do not represent the simple progressive “wearing away” of cartilage that many people assume occurs with running. Some biomechanical research also suggests that cartilage may positively adapt to repeated loading over time.
Possibly. An osteoarthritis diagnosis does not automatically mean you need to stop running. Your symptoms, previous injuries or surgeries, current physical capacity, and training history should all be considered. Recent MRI research in experienced runners with knee OA has not shown evidence of widespread cartilage degeneration compared with runners without OA.
Strength training can be useful for runners because it improves the capacity of the muscles that help produce and absorb force during running. Exercise, including resistance training, is also commonly used to improve pain, strength, and function in people with knee osteoarthritis. Persistent or worsening knee pain should be appropriately assessed.
References
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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). Is running good or bad for your knees? A systematic review and meta-analysis of cartilage morphology and composition changes in the tibiofemoral and patellofemoral joints. Osteoarthritis and cartilage, 31(2), 144–157. https://doi.org/10.1016/j.joca.2022.09.013
Dhillon, J., Kraeutler, M. J., Belk, J. W., Scillia, A. J., McCarty, E. C., Ansah-Twum, J. K., & McCulloch, P. C. (2023). Effects of Running on the Development of Knee Osteoarthritis: An Updated Systematic Review at Short-Term Follow-up. Orthopaedic journal of sports medicine, 11(3), 23259671231152900. https://doi.org/10.1177/23259671231152900
Hart, H. F., Patterson, B. E., Crossley, K. M., Culvenor, A. G., Khan, M. C. M., King, M. G., & Sritharan, P. (2022). May the force be with you: understanding how patellofemoral joint reaction force compares across different activities and physical interventions-a systematic review and meta-analysis. British journal of sports medicine, 56(9), 521–530. https://doi.org/10.1136/bjsports-2021-104686
Horga, L. M., Henckel, J., Fotiadou, A., Hirschmann, A., Torlasco, C., Di Laura, A., D’Silva, A., Sharma, S., Moon, J., & Hart, A. (2019). Can marathon running improve knee damage of middle-aged adults? A prospective cohort study. BMJ open sport & exercise medicine, 5(1), e000586. https://doi.org/10.1136/bmjsem-2019-000586
Hunt, M. A., Khan, M. C. M., Krowchuk, N. M., Gatti, A. A., Rauscher, A., & Esculier, J. F. (2026). Measures of resting cartilage structure and composition in runners with and without knee osteoarthritis. Osteoarthritis and cartilage open, 8(2), 100797. https://doi.org/10.1016/j.ocarto.2026.100797
Khan, M. C. M., O’Donovan, J., Charlton, J. M., Roy, J. S., Hunt, M. A., & Esculier, J. F. (2022). The Influence of Running on Lower Limb Cartilage: A Systematic Review and Meta-analysis. Sports medicine (Auckland, N.Z.), 52(1), 55–74. https://doi.org/10.1007/s40279-021-01533-7
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, e9676. https://doi.org/10.7717/peerj.9676
Ponzio, D. Y., Syed, U. A. M., Purcell, K., Cooper, A. M., Maltenfort, M., Shaner, J., & Chen, A. F. (2018). Low Prevalence of Hip and Knee Arthritis in Active Marathon Runners. The Journal of bone and joint surgery. American volume, 100(2), 131–137. https://doi.org/10.2106/JBJS.16.01071
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