Phys Ed: Can Running Actually Help Your Knees?

“In article in Skeletal Radiology, a well-respected journal, created something of a sensation in Europe last year. It reported that researchers from Danube Hospital in Austria examined the knees of marathon runners using M.R.I. imaging, before and after the 1997 Vienna marathon. Ten years later, they scanned the same runners’ knees again. The results were striking. ‘No major new internal damage in the knee joints of marathon runners was found after a 10-year interval,’ the researchers reported. Only one of the participants had a knee that was truly a mess, and he’d quit running before the 1997 marathon (but had been included in that study anyway). His 1997 knee M.R.I. revealed cartilage lesions, swelling and other abnormalities. In the years that followed, the knee became worse, showing augmented tissue damage and more serious lesions. His exam prompted the researchers to wonder whether he would have been better off persisting as a runner, because, as they speculate, ‘continuous exercise is protective, rather than destructive,’ to knees.”

http://well.blogs.nytimes.com/2009/08/11/phys-ed-can-running-actually-help-your-knees/