You may have heard that running is bad for your knees, from well-meaning family members, friends, colleagues or even doctors and healthcare professionals. By ‘bad for your knees’ what they are actually likely meaning is that they believe that running can cause, increase the risk of, or worsen, osteoarthritis.
We have written a separate, more detailed post on osteoarthritis here. If you would like to know more about this complex and multifactorial disease of the joints it is well worth a read, or bookmarking and coming back to. There is rarely one obvious cause of osteoarthritis, but there are a number of known risk factors which include: increasing age, female sex, obesity, prior injury to the joint, low bone density, muscle weakness, joint laxity, some genetic factors and prior repetitive over-use of the joint.
It is that last point – prior repetitive over-use of the joint which is often used as the rationale for the fear of running.
So, let’s explore the evidence.
We are going to break this down to answer the following questions:
- Does running increase the risk of developing knee osteoarthritis?
- Does running make knee osteoarthritis worse?
- Can running be protective against osteoarthritis?
Does running increase the risk of developing knee osteoarthritis?
A large systematic review evaluated the current evidence on the prevalence of knee and hip osteoarthritis in runners (1). The review and analysis included 25 studies with data from over 125,000 individuals. The review analysed the studies for the overall prevalence of hip and knee osteoarthritis in non-runners, recreational runners (non-professional runners), and competitive runners (runners who reported as professional or elite athletes).
The prevalence rate of hip and knee osteoarthritis found were:
- 10.2% in non-runner controls
- 3.5% in recreational runners
- 13.3% in competitive runners
To repeat that: 3.5% in recreational runners – that would be most of us! A third of the rate of non-runners! And even the competitive runners only presented a slightly increased rate of osteoarthritis.
Evidently this is a huge study and therefore it isn’t possible to adjust for all the potential confounding risk factors in the development of osteoarthritis. But this is an extremely large, high quality systematic review based on data from over 125,000 individuals.
In our opinion these results should be plastered all over the walls GP surgeries and health centres. And you should quote these figures next time someone tells you that running is bad for your knees!
If you want some evidence more specific to older adults, and even specific to longer distance running in older adults, one study followed participants over two decades (2). The group compared long distance runners >50 years old to control groups. At baseline 6.7% of the runners showed initial radiographic osteoarthritic changes, compared to 0 in the control group. But by the end of the study, the long distance runners showed less overall osteoarthritis (20% compared to 32%) and less severe osteoarthritis (2.2% compared to 9.4%)!
Remarkably, this suggests that long distance running not only reduces the risk of osteoarthritis, but also the severity if it does develop.
Does running make knee osteoarthritis worse?
Another study followed 1203 participants over the age of 50 with osteoarthritis in at least one knee over a number of years, with radiographic comparisons (scans) and symptom assessment at baseline and after 4 years (3). Self-selected runners were compared to non-runners. Contrary to expectations, running was not associated with disease progression and the runners actually reported improvements in knee pain and symptoms compared to the non-runners.
These results didn’t change when adjusted for age, sex, BMI and injury. Of course, this is only an observational study, so it doesn’t show causation; the running is also ‘self-selected’ and not mandated or tracked, so the extent of the running isn’t known. However it does provide evidence against the commonly held belief that running worsens osteoarthritis progression and symptoms.
So even if osteoarthritis is already diagnosed, the evidence does not suggest that running worsens disease progression. And running may in fact lead to symptom relief!
Can running be protective against osteoarthritis?
Here comes more good news. A number of studies have shown positive joint adaptations following short and long term running programmes.
Novice female runners on a 10 week Start to Run programme were compared to sedentary age-matched controls in one study: the Start to Run group showed a significant increase in knee cartilage quality after the 10 weeks (4).
Positive joint responses to already ‘damaged’ joints have also been seen in longer distance running programmes. A 4-month marathon training programme was found to actually improve damaged subchondral bone in middle-aged adults (5).
To summarise, the evidence tells us that:
- Recreational running does not increase the risk of osteoarthritis
- Running does not worsen osteoarthritis in terms of disease progression or symptoms
- Running may cause positive joint adaptations, protecting against osteoarthritis development and progression
This video is a great summary of some of the main studies discussed here:
So, what does this mean for you?
This article isn’t trying to encourage everybody to go out and buy new running shoes. Everybody is individual. You may not enjoy running. You may actually despise it and prefer many other forms of exercise, which is completely fine. You may find running to cause significant knee pain, whether or not you have osteoarthritis.
However if you do enjoy running already, or if you are interested in starting, this article should reassure you.
If you are looking to get started, or progress your running:
- Take it slow
- Consider starting on a running programme to help you progress gradually- the NHS Couch to 5K app is a great place to start
- Warm up, cool down
- Consider your footwear and the surfaces you are running on
- Take adequate rest days
And finally, but perhaps most importantly in our opinion:
- Incorporate a strength training programme
There are a number of reasons why strength training is increasingly important as we get older. And it is even more important if you are asking your body to cope with the added demands of running. If you are interested in learning more about the effects specifically for osteoarthritis, check out this list of 10 key benefits of strength training for osteoarthritis.
Need some help getting started? Give one of our free 6 week strength training programmes a go!