Is Running Bad for Your Knees? What the Research Says

For most people, no. A 2017 review that pooled 17 studies and nearly 115,000 people found hip or knee arthritis in 3.5% of recreational runners, 10.2% of non-runners and 13.3% of elite competitive runners. That's an association, not proof, but the research doesn't back the idea that everyday running wears out healthy knees.

The short answer

Running as a hobby is not linked to more knee arthritis. In a large review of the research, recreational runners actually had less of it than people who didn't run.¹

Two caveats matter. Very high-volume, elite-level running is linked to more arthritis than recreational running. And running does cause plenty of knee pain, but mostly through overuse injuries, which are a different problem from worn-out joints.

What the biggest review found

Alentorn-Geli and colleagues searched three medical databases for studies of hip and knee arthritis in runners. They found 25 studies covering 125,810 people and combined 17 of them, covering 114,829 people, in a meta-analysis.¹

They sorted runners into two groups. "Competitive" meant professional or elite athletes, or people who raced internationally. "Recreational" meant anyone running as an amateur. The comparison group was sedentary people who didn't run.

Time spent running mattered too. People who had run for less than 15 years had lower odds of hip or knee arthritis than non-runners (odds ratio 0.6).¹

What this review can't tell you

The studies in it observed people rather than randomly assigning anyone to run. The authors say directly that they couldn't tell whether running caused the differences or whether something else, such as earlier injuries, explained them.

• The percentages are pooled across many separate studies. Read them as a broad picture, not as your personal risk.
• When each runner group was compared with non-runners in the same studies, neither gap was statistically clear-cut on its own. The sharper difference was between recreational and elite runners.
• People whose knees start to hurt may quit running, which would make the runners who stay look healthier. Observational studies can't fully rule that out.

So the fair reading is this: running as a hobby isn't linked to more arthritis, and years of very heavy competitive running may be.

Why doesn't running wear out your knees?

It seems like it should. Each running stride sends far more force through the knee than a walking step. In a lab study of 14 healthy adults, the estimated peak force on the knee was about three times higher when running (8.02 times body weight) than when walking (2.72 times).²

But running covers ground with longer strides and shorter contact with the floor. When the researchers worked out the knee load for each meter traveled, running and walking came out about the same: 0.80 versus 0.75 body weights per meter.² To cover a mile, you take fewer, harder steps when you run and more, gentler steps when you walk.

This was one small study using computer modeling, and it doesn't prove why runners avoid arthritis. It does show that "running pounds your knees" is too simple a story.

What about people who run for decades?

Three other studies looked at long-term runners. Each has real weaknesses, but they point the same way as the review.

• Eighteen years of X-rays. Researchers followed 45 long-distance runners and 53 non-runners, average age 58 at the start, from 1984 to 2002.³ By the end, 20% of the runners and 32% of the non-runners had arthritis on X-ray, and severe arthritis showed up in 2.2% versus 9.4%. Those differences weren't statistically significant, which isn't surprising with fewer than 100 people. The takeaway is that the runners were not worse off.
• Marathon runners. A survey of 675 active marathoners, each with at least five marathons and still running 10 or more miles a week, found that 8.8% of the US runners reported hip or knee arthritis. National estimates for a matched group of Americans came in at 17.9%.⁴ Age, family history and past surgery predicted arthritis. Mileage, running intensity and number of marathons did not. The survey relied on self-report and only reached people still running.
• A large community group. Among 2,637 adults with an average age of 64 in a US arthritis research cohort, people who ran now or had run in the past were no more likely to have frequent knee pain or painful knee arthritis than people who had never run. Their odds were, if anything, lower.⁵ This was a snapshot in time, and people chose for themselves whether to run.

Why do so many runners get knee pain, then?

Because injuries and arthritis are different things. Running injuries are common, and many come from overuse. A 2021 systematic review found that the knee, ankle and lower leg accounted for the biggest share of new running injuries.⁶ Pain around the kneecap, often called runner's knee, was the most common specific injury in the studies that asked runners about past problems.⁶

Overuse injuries are tied to how much and how fast you train, which is a different problem from cartilage wearing away. That's why the way you build up matters so much.

Can you run if you already have knee arthritis?

Possibly, but this is a decision to make with your doctor or physical therapist, and the evidence is thinner.

The most useful data come from 1,203 people aged 50 and over who already had arthritis in at least one knee and were tracked for about four years.⁷ The 11.5% who chose to run were no more likely to see their arthritis worsen on X-ray or to develop new frequent knee pain. They were somewhat more likely to say their knee pain had cleared up. Again, people chose whether to run, so those with the worst knees may simply have avoided it.

More broadly, osteoarthritis guidance from England's National Institute for Health and Care Excellence names tailored exercise as a core treatment and warns that joint pain may rise when you first start.⁸ That guidance covers exercise in general, not running in particular.

How to run with healthy knees

None of the studies above tested a specific training plan, so treat this list as standard coaching guidance, not a study result.

1. Start with run/walk. If you're new, alternate short runs with walking breaks. Our guide to going from zero to 30 minutes of running has a week-by-week example.
2. Build slowly. Add a little running each week instead of jumping from two runs to five. Repeat a week if your knees are sore the next day. If you'd rather not plan it yourself, Rep Labs running plans start at couch-to-5K and are paced off your current fitness.
3. Keep most runs easy. You should be able to speak in full sentences while you run.
4. Strengthen your legs. Squats, lunges and step-ups train the muscles that control the knee. Our guide on whether deep squats are bad for your knees covers how to do them well.
5. Treat pain as information. Pain that makes you limp, gets worse as you run, or is worse each week is a reason to stop and get checked.
6. Keep the bigger factors in view. In the long-term studies above, age, body weight, past surgery and family history were the factors tied to arthritis, more than running itself.^3,4

The bottom line

For healthy knees, recreational running is not the joint-wrecker it's made out to be. The best evidence links it to the same or less arthritis than sitting still, with more arthritis showing up mainly in elite athletes with years of heavy training.

The research is observational, so it can't promise anything for you personally. What it does show is that running at a sensible volume, built up gradually, is a reasonable choice for most people's knees. If yours already hurt, get them checked first.