Health & Fitness

Does Running Really Harm Your Knees?

Kristen Sparrow • October 19, 2022

Top view of fitness woman running on pavement

“Does Running Really Wreck Your Knees?”

Contrary to popular opinion, distance running rarely causes knee problems in runners, and often leaves joints sturdier and less damaged.

Study after study indicates running rarely causes or exacerbates arthritis in most runners’ knees, even older runners, who are at relatively high risk for arthritis.

Can running build stronger knees?

Shifting the public’s perceptions is hard, however, said Alister Hart, an orthopedic surgeon and research professor at University College London, who used to worry about his own knees, especially after he finished his first marathon and limped afterward for days. At that point, he decided, he should delve more deeply into the effects of this consuming activity on runners’ joints…

some runners showed symptoms of new, if slight, damage in the bones and cartilage right around their kneecaps, a part of the joint that absorbs much of the pounding from running. “We could not ignore this, since it likely happened because of the training and racing,” said Johann Henckel, a study co-author and also an orthopedic surgeon at University College London and the Royal National Orthopaedic Hospital. “So then, we had to ask, does this damage last or get worse?”

If it did, running was harming people’s knees.

The scientist-surgeons helped settle that concern, though, with a follow-up study, published in 2020, during which they scanned the runners’ knees again, six months after their race. Most of them still ran, although with reduced mileage.

The new scans showed their knees were healthier now than in the weeks right after the marathon. Many of the lesions and tears that had begun shrinking during training were smaller and the fresh damage seen around some kneecaps had largely dissipated, with few remaining signs of lesions and tears.

“I feel comfortable at this point saying running should not harm most people’s knees and can, in fact, be beneficial,” Hart said

So, for a 2019 study, he and his orthopedic colleagues recruited 82 middle-aged, first-time racers who had signed up for the 2017 London Marathon. Few had done much, if any, previous running and none felt knee pain. The researchers scanned the runners’ knees before they