Contrary to popular wisdom, running might not be so bad for your knees after all. In fact, it may actually improve your knee health.
One reason that running is assumed to be bad for your knees is the existence of “runner’s knee,” or patellofemoral pain syndrome. It’s fairly common for runners to experience knee pain, especially those who are new to the sport. That pain is often due to muscle weakness, overextending yourself, or running with old shoes.
But studies have shown that running is not associated with knee arthritis or other types of degenerative joint disease. In fact, it may be good for your knee joints, helping to protect the knee and keep it working smoothly.
In one 2016 study, male and female runners either ran on a treadmill for 30 minutes or sat quietly for 30 minutes. Then they did the opposite activity on the next day. Before and after each session, the researchers drew blood from their arms and synovial fluid from their knees. They measured it for cells linked to inflammation and cartilage oligomeric matrix protein (COMP), the substance that marks arthritis.
After 30 minutes on the treadmill, participants had lower levels of inflammation and lower levels of COMP. Sitting for 30 minutes increased those same levels. The study’s author Robert Hyldahl concluded that moderate runs are “not likely to harm healthy knees and probably offer protection,” per the New York Times.
So you definitely shouldn’t let the fear of bad knees keep you from running.
Still, it’s important to practice good etiquette to avoid messing up your knees — wear proper running shoes, and don’t push yourself too far too soon.