You can’t be a runner past the age of 40, as I am, without hearing that running will ruin your knees, by which doomsayers usually mean that we’ll develop “degeneration of the cartilage in the kneecap, which reduces its shock-absorbing capacity,” says Ross Tucker, a physiologist in South Africa and co-author of the new book “The Runner’s Body: How the Latest Exercise Science Can Help You Run Stronger, Longer and Faster.” In other words, we’ll be afflicted with arthritis.
It seems to be common knowledge that certain sports and exercises such as distance running are bad because of the eventual suffering in the knees by participants. A long term study of runners has found that there is no particular reason for that to be the case simply because the knees are being used more often and in a tougher fashion than walking or other milder exercises.
In fact the opposite is true:
Instead, recent evidence suggests that running may actually shield somewhat against arthritis, in part because the knee develops a kind of motion groove. A group of engineers and doctors at Stanford published a study in the February issue of The Journal of Bone and Joint Surgery that showed that by moving and loading your knee joint, as you do when walking or running, you “condition” your cartilage to the load. It grows accustomed to those particular movements. You can run for miles, decades, a lifetime, without harming it. But if this exquisite balance is disturbed, usually by an injury, the loading mechanisms shift, the moving parts of the knee are no longer in their accustomed alignment and a “degenerative pathway” seems to open. The cartilage, like an unbalanced tire, wears away. Pain, tissue disintegration and, eventually, arthritis can follow.
The key factor is injury. Preventing an injury by strengthening the muscles involved in running is a good start. Once an injury has been sustained, it is likely to lead to another and possibly cause even more damage, so always consult with a doctor before resuming a normal running regimen.