Keep running to avoid arthritis

BRITAIN: For a mean-spirited couch potato, the great consolation of seeing a runner dash past, glowing with health and vigour, is knowing that arthritis will get them eventually.

Except, now, according to a major new study, it won’t. Or at least, runners have a significantly better chance of avoiding the painful condition than the average member of the public.

The counter-intuitive conclusion is the result of a 31-country review which compared rates of arthritis and joint pain among marathon enthusiasts with the wider population.

The researchers at Thomas Jefferson University in Philadelphia found that, while the general prevalence of arthritis was 17.9 per cent, among marathon runners it was only 8.8 per cent.

While previous research examining joint damage among athletes has yielded mixed results, many scientists have assumed that running inevitably causes damage to the hips and knees.

This is because the joint-load force while running is approximately eight times body weight through the knee and five times through the hip.

However, researchers now believe that because runners tend to have better bone density, muscle mass and body-weight ratio, combined with their long stride and relatively short duration of ground contact, the force exerted on the joint is not much different to walking.

The greater the number of marathons completed, the less were the chances of joint pain although the authors said this result may reflect self-selection, whereby athletes in pain give up running.

The only pronounced risk factor facing runners, according to the study, was a history of hip or knee surgery, which is present in approximately 13 per cent of long distance runners.

Of these people who kept running, about four in 10 reported problems.

Professor Richard Steadman, a sports injury specialist at the University of Texas, said: ‘‘If you have not had surgery on your knee, and you’re anatomically aligned properly, then you could be running forever.

‘‘My advice to people is, as long as they’re not symptomatic, they should keep on running.’’

Published in The Journal of Bone and Joint Surgery, the study examined 675 regular runners, with an average age of 48, who ran an average of 36 miles a week over approximately 19 years.

The team also collected data on people who had stopped running, finding that knee pain was the most common reason given.

They found that, as with the general population, the risk of arthritis was higher in female runners compared to males, but still better than non-runners.