When you run, every step you take can land with a force equal to almost four times your body weight. Run a mile, and you’re taking 1,500 steps like that. Sure, we’re all born to run, and perhaps even evolutionarily adapted to chase skittish deer across miles of open plain. But our ancestors weren’t running on concrete and the average hunter was probably carrying less weight than the typical London Marathon first-timer. So if you take up running – or have been doing it for decades – are you setting yourself up for creaking knees and other niggles in old age?
Just in case this is as far as you read, the answer is no, probably not. Performance coach Joseph Lightfoot says: “Lots of studies show that runners have lower instances of knee osteoarthritis than sedentary people. There are also papers which show that runners report less knee pain than sedentary people, and being a runner is linked to reduced disability in later life. Overall, the message from the research is that running is a good thing.”
To understand why this is the case, it helps to have a handle on the current scientific thinking around osteoarthritis. Chances are, you’re still thinking of this condition – the most common form of arthritis in the UK – as something associated with your knees wearing out over time, a process that endless pavement pounding would probably exacerbate. Now, it’s better understood as a disease of the entire joint, including bone, cartilage, ligaments, fat and tissue. And here, running can be protective, rather than dangerous.
A recent meta-analysis, for instance, found that changes to cartilage in the knee joint after running are temporary, and some researchers suggest that running might actually condition cartilage, leading to better overall knee health. Other studies suggest that runners are less likely to develop osteoarthritis and have a lower rate of hip replacements, in part due to their lower BMI.
Of course, this doesn’t make your precious knees invincible: knee injuries are still one of the most common afflictions among runners. “Obviously there are various other factors to consider,” says Lightfoot. “Body weight, running technique, shoes and so on all come into play, but the biggest mistake most people make early on is going too hard, too fast. If you’re out of shape, start with walking, then brisk walking, then intermittent jogging and walking, then longer periods of steady jogging. Be patient.”
You can also mitigate your risk of issues caused by imbalances elsewhere in the body, for instance the hips, by including some strength and balance work alongside your regular running. “There’s plenty you can do at home with no equipment,” says Lightfoot. “For instance, a single-legged Romanian deadlift and a reverse lunge will strengthen your quads, hips and hamstrings, while core work like planks and dead bugs will help prep the body for running.”
He recommends using balance work to prepare the feet and ankles. “Balance on one leg with a slight leg bend, starting with both eyes open, then progressing to eyes closed. You can even add the challenge of playing catch with a tennis ball while standing so you’re not completely focused on balance – keep your eyes open for that, though.”
What about shoes? Well, this is where things get controversial: more than one study suggests that highly cushioned running shoes do little to mitigate injury risk, and some research suggests that they hurt rather than help. By cushioning your feet, the theory goes, they enable you to run with bad form – for instance, landing on your heels rather than your shock-absorbing toes – meaning that, counterintuitively, minimal footwear may actually help.
More generally, checking up on your form may be a good idea: modern running shoes let us run in an “overstriding” style that we’re not evolutionarily well adapted to, even though our knees can handle a fair bit of up-and-down bouncing. This means that taking more steps a minute may help, by stopping us from exerting too much horizontal “braking force” on our knees.
And what about changing the surface you run on? Perhaps not surprisingly, there are few studies on runners who stick exclusively to one surface over another, but running on grass certainly seems to reduce the forces you’re subjecting yourself to with each foot strike. It’s also worth remembering that running through greenery can improve your mood, keep you away from pollution, and even reduce your blood pressure. After all, it’s not all about your knees.