Is running bad for your knees?

Have you heard or been told that “running is bad for your joints”? As a physiotherapist I often see people with knee/hip pain who tell me that they used to run a lot and so must have worn out their joints. The medical term for ‘joint wear’ is osteoarthritis which is characterised by joint pain with activity and stiffness particularly after a period of rest in people aged 45+.

So does running increase the likelihood of developing osteoarthritis? Should we advise people with osteoarthritis to stop running to protect their joints as many of my patients have been told?

A small study decided to test this theory by following a group of 43 runners (age 50+) from 1984 – 2002 and comparing them to a group of non-runners. They did repeat knee x-rays throughout this 18 year period and found there was no difference in the prevalence or progression of knee OA on x-ray between runners and non-runners (1).

Another study compared 675 marathon runners (running an average of 35 miles per week) to matched data from the US population (2). The results are well summarised in the following graphs:

Knee OA in marathon runners

These graphs show that when matched for age, gender, body mass index and activity levels prevalence of knee osteoarthritis was significantly lower in marathon runners.

So it seems that running, even at relatively high volume, does not cause joints to ‘wear out’ and if anything may be protective against osteoarthritis. However, as ever with science and research it’s not entirely black and white! It’s very difficult to fully account for the effects of other behaviours as running is likely to cluster with other healthy lifestyle choices and so benefits seen may partly be due to other factors such as diet, smoking and general health. But certainly the data suggest that running is not bad for your knees.

What about continuing to run after you’ve been told you have osteoarthritis?

Well a study following 136 runners with a diagnosis of knee osteoarthritis for 4 years found that continuing to run at a self-selected intensity did not speed up the arthritis process or worsen reported knee pain. In fact compared to similar non-runners with osteoarthritis the runners were more likely to experience an improvement in their knee pain (3).  

So to sum up, the evidence suggests that running does not wear joints out and if anything may be protective against osteoarthritis. Continuing to run with osteoarthritis is absolutely fine and may actually reduce pain over time. It seems the best way to protect your joints is to use them.

So the next time someone tells you that running is bad for your knees you can tell them to jog on!