Marathons And Your Knees

From the NY Times online…

October 13, 2010, 12:01 am

Phys Ed: Do Marathons Hurt Your Knees?

By GRETCHEN REYNOLDS

About this time every year, with the fall marathon season at its zenith, racers in training begin to hear the refrain, ‘‘You are going to ruin your knees.’’ The idea that distance running inexorably leads to arthritis is deeply entrenched, despite the publication of a number of recent studies (detailed in a Phys Ed column last year) that have found otherwise. In one representative experiment, the knees of experienced marathoners, with multiple races behind them, were scanned with magnetic resonance imaging technology, and then scanned again 10 years later. The runners’ knees were and remained robust throughout that time, with few significant cartilage abnormalities. The only truly unhealthy knee in the study belonged to a former marathoner, who had quit the sport. In the years since he stopped running, his joint had deteriorated badly.

But then came the latest study on the issue, this one from researchers at the University of California at San Francisco, using a more sensitive type of M.R.I. technology than had been available in the past. For this study, the researchers recruited a group of beginner marathon runners. The runners were 40 and younger and had completed fewer than three marathons in their lifetimes. Some were training for their first. At the time they enrolled in the study, none of the runners reported knee problems. ‘‘They had virgin knees,’’ said Anthony Luke, M.D., director of primary care sports medicine at U.C.S.F. and the study’s lead investigator. In the days before the runners’ marathons (either the San Francisco or Nike women’s marathon), they scanned the racers’ knees, employing a type of M.R.I. technology that evaluates the metabolic activity and health of the cartilage at a cellular level. They repeated the scans within 48 hours after the event and again about three months later.

Read on here.