Almost every recreational runner has heard it before: “Running is bad for your knees.” Whether it comes from a concerned friend, a well-meaning family member, or a skeptical onlooker, the myth persists. But is there any truth to it?
The short answer: no. Research doesn’t support the idea that running ruins your knees. In fact, studies consistently show that recreational runners are less likely to develop knee osteoarthritis than non-runners.
As a running coach, I hear this concern all the time—and I always reassure my athletes with what the evidence actually says.
In this guide, we’ll break down the science of running and knee health, drawing from orthopedic experts and current research to finally answer the question: Is running bad for your knees?
Is Running Bad for Your Knees?
The good news is that research has shown that runners don’t seem to be at any higher risk of developing osteoarthritis than non-runners, and in fact, running may reduce the risk of osteoarthritis, according to some studies.
A study that followed runners and non-runners over a period of 18 years found that there was no discernible difference in radiographic evidence of arthritis in runners compared to non-runners.1Chakravarty, E. F., Hubert, H. B., Lingala, V. B., Zatarain, E., & Fries, J. F. (2008). Long Distance Running and Knee Osteoarthritis. American Journal of Preventive Medicine, 35(2), 133–138. https://doi.org/10.1016/j.amepre.2008.03.032
Other research has shown that marathoners and long-distance runners may have healthier knees than sedentary age-matched peers.2Ponzio, 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. Journal of Bone and Joint Surgery, 100(2), 131–137. https://doi.org/10.2106/jbjs.16.01071
Studies have also found that running can improve the health of the spine, another indication that running doesn’t cause joint damage or osteoarthritis.3Mitchell, U. H., Bowden, J. A., Larson, R. E., Belavy, D. L., & Owen, P. J. (2020). Long-term running in middle-aged men and intervertebral disc health, a cross-sectional pilot study. PLOS ONE, 15(2), e0229457. https://doi.org/10.1371/journal.pone.0229457
What Is Knee Osteoarthritis?
Knee osteoarthritis is a degenerative condition that involves a loss of the cartilage on one or both sides of your knee joint.
Because knee osteoarthritis is considered a degenerative condition, the loss of knee cartilage is sometimes referred to as “wear and tear“ on the knee joint.
Cartilage is a smooth tissue that provides cushioning within the knee joint to help attenuate forces.
Cartilage wraps around the ends of the long bones that comprise the knee joint, which are the femur or thigh bone, along with the tibia (shin bone), and the patella (kneecap).
Essentially, the tibial plateau, the bulbous end of the femur, and the back of the knee cap have this protective, smooth cartilage around the bony surfaces where they articulate or connect with one another.
The knee cartilage is not only thick and spongy to provide cushioning, but it is also glossier and slick unlike rough bones.
Therefore, the knee cartilage tissue not only cushions the joints, but because it is also very smooth and lubricated, it decreases friction between the bones in the joint. This allows the bones in the knee joint to glide easily when you bend and straighten your knee.
When you have knee osteoarthritis, wear and tear on the knee joints has gradually but progressively worn away the healthy cartilage tissue, leaving the cartilage thin, cracked, and no longer fully intact or smooth.
This means that the femur and tibia do not glide smoothly against one another with flexion and extension of the knee joint.
This can cause what is known as crepitus, or what people describe as a feeling of stiff knees, creaky knees, popping or cracking of the knees, or knees that feel like there are Rice Krispies in them.
More importantly, because the cartilage acts as a shock absorber and prevents the two bones from rubbing up on one another, osteoarthritis of the knee results in knee pain.
There are nerves within the knee joint capsule, and once you have lost knee cartilage surrounding the patella, femur, and tibia in the knee joint, the lack of cushioning can cause knee pain while running, squatting, walking, and sometimes even standing.
What Really Causes Knee Osteoarthritis (Hint: It’s Not Recreational Running)
Although knee osteoarthritis is often chalked up to being “wear and tear“ on the knee joint, most orthopedic surgeons and medical researchers suggest that running does not cause osteoarthritis of the knee and is not a major risk factor for the degeneration of cartilage in the knee joint.4Alentorn-Geli, E., Samuelsson, K., Musahl, V., Green, C. L., Bhandari, M., & Karlsson, J. (2017). The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis. The Journal of Orthopaedic and Sports Physical Therapy, 47(6), 373–390. https://doi.org/10.2519/jospt.2017.7137
Rather, there are other risk factors for knee osteoarthritis, some of which are non-modifiable while others can potentially be modified with lifestyle changes:
Non-Modifiable Risk Factors for Knee Osteoarthritis
- Age: The risk of developing knee osteoarthritis increases with age.
- Sex: Studies suggest that the prevalence of knee injuries, including osteoarthritis, is higher in females.5Hsu, H., & Siwiec, R. M. (2019). Knee Osteoarthritis. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK507884/
- Genetics: Family history, or genetics, can be a risk factor, with some researchers suggesting that the incidence of knee OA is 40% higher in those with a family history of this knee condition.6Hsu, H., & Siwiec, R. M. (2019). Knee Osteoarthritis. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK507884/
- Previous Knee Injuries: Here is the one area where running can potentially contribute to knee osteoarthritis risk.
Studies suggest that having a previous knee injury, such as a meniscus tear or an anterior cruciate ligament (ACL) tear, is a significant risk factor for knee osteoarthritis.
Recreational runners and competitive runners are generally unlikely to have an ACL tear, but there is a risk of running injuries to the knee, such as meniscus tears, IT band syndrome, and patellofemoral pain syndrome, among others.
You are at an increased risk for these injuries if you have poor running form, increase your training too quickly, or do not wear the right running shoes for your needs.
Therefore, runners who incur running injuries to the knee can therefore potentially increase their risk of developing osteoarthritis later on in life.
Somewhat Modifiable Risk Factors for Knee Osteoarthritis
- Excess Body Weight: The prevalence of knee injuries, knee pain, and premature wear and tear on the knee cartilage is higher in people with obesity or high body weight.
- Poor Running Technique: Poor running form or improper running technique, or other improper biomechanics with walking, running, squatting, and other types of physical activity can potentially contribute to wear and tear on the knee cartilage and eventual development of knee osteoarthritis.
- Muscle Imbalances: It is possible that muscle imbalances and muscle weakness surrounding the knee joint can alter the forces and stability of the knee.
The hamstrings oppose the quads, so having a good balance of strength in these muscles is critical for controlling knee flexion and extension and loading of the knee joint when walking, running, climbing stairs, squatting, etc.
Additionally, weakness in different muscles in the quads can potentially change the angle of force through the knee joint and your running technique or biomechanics.
Iliotibial band syndrome, or IT band syndrome, and Patellofemoral pain syndrome (runner’s knee) can potentially result from imbalances in the quads muscle group. The calves also play a role in controlling knee flexion, but to a lesser extent than the hamstrings.
The glutes also are involved in controlling the extension of the leg, which may then affect running technique, foot strike, and knee stability. Therefore, strength training to correct muscle imbalances can help reduce your risk of injury to the knee joint.
- Overuse: Orthopedic surgeons suggest that heavy occupational use or sports participation can potentially cause premature wear and tear on the knee joints, especially if you are doing a lot of kneeling, jumping, or squatting with poor technique. However, cartilage should “bounce back” after workouts with adequate rest days.7Khan, M. C. M., O’Donovan, J., Charlton, J. M., Roy, J.-S., Hunt, M. A., & Esculier, J.-F. (2021). The Influence of Running on Lower Limb Cartilage: A Systematic Review and Meta-analysis. Sports Medicine. https://doi.org/10.1007/s40279-021-01533-7
Will Running Make Knee Arthritis Worse?
Although you should discuss running with your doctor because your needs may be different, there’s evidence to suggest that running does not exacerbate arthritis.
A recent study that followed runners with knee osteoarthritis over a 4-year period found that not only did running not worsen clinical arthritis symptoms nor radiographic evidence of arthritis on x-rays, but it also seemed to help alleviate subjective measures of knee pain.8Lo, G. H., Musa, S. M., Driban, J. B., Kriska, A. M., McAlindon, T. E., Souza, R. B., Petersen, N. J., Storti, K. L., Eaton, C. B., Hochberg, M. C., Jackson, R. D., Kwoh, C. K., Nevitt, M. C., & Suarez-Almazor, M. E. (2018). Running does not increase symptoms or structural progression in people with knee osteoarthritis: data from the osteoarthritis initiative. Clinical Rheumatology, 37(9), 2497–2504. https://doi.org/10.1007/s10067-018-4121-3
According to the Arthritis Foundation, running can even be a healthy way to manage symptoms of osteoarthritis.9Running Safely With Knee Osteoarthritis | Arthritis Foundation. (n.d.). Www.arthritis.org. https://www.arthritis.org/health-wellness/healthy-living/physical-activity/other-activities/running-safely-with-knee-osteoarthritis
How Can I Prevent Knee Pain From Running?
While running isn’t inherently bad for your knees, recreational runners often do experience knee pain due to underlying knee issues or problems, biomechanical issues with running form, and other issues.10Lo, G. H., Driban, J. B., Kriska, A. M., McAlindon, T. E., Souza, R. B., Petersen, N. J., Storti, K. L., Eaton, C. B., Hochberg, M. C., Jackson, R. D., Kent Kwoh, C., Nevitt, M. C., & Suarez-Almazor, M. E. (2017). Is There an Association Between a History of Running and Symptomatic Knee Osteoarthritis? A Cross-Sectional Study From the Osteoarthritis Initiative. Arthritis Care & Research, 69(2), 183–191. https://doi.org/10.1002/acr.22939
Tips To Prevent Knee Pain While Running
- Run on softer surfaces. Running is a high-impact activity, so trail running, running on grass, or a cushioned treadmill deck can help reduce joint stress.11NILSSON, J., & THORSTENSSON, A. (1989). Ground reaction forces at different speeds of human walking and running. Acta Physiologica Scandinavica, 136(2), 217–227. https://doi.org/10.1111/j.1748-1716.1989.tb08655.x
- Don’t overstride. Running technique issues like overstriding can put stress on your knees. Work on increasing your cadence and landing lightly in your midfoot.
- Get the right shoes. Wear proper running shoes and replace them every 300-500 miles (500-800 km).
- Warm up before your workouts. Ease into faster running with a warm up to increase blood flow to the muscles and increase circulation of synovial fluid (joint fluid) in the knees.
- Strength train. Work on strengthening the quads, glutes, hamstrings, calves, hip flexors, core muscles, adductors, and abductors. Correct muscle imbalances that may lead to running injuries.
Overall, running shouldn’t be bad for your knees, but if you have concerns or experience a knee injury, work with a physical therapist or doctor to address your pain.
For a guide to how to increase your volume with out overtraining and increasing your risk of knee pain, check out this next guide:
Another thing to call out is that tight quads can often be mistaken for a knee injury or knee pain. Stretching those quads is super important, especially if you have a lot of downhill. Great article though!