Tuesday, July 7, 2009

Is Bicycling Bad for Your Bones?

Seems to strengthen the argument that it's critical to take calcium when you're cycling heavily:

In 2006, Aaron Smathers, then 29, was a graduate student in the Department of Health and Exercise Science at the University of Oklahoma, gathering data for a study of brittle bones in cyclists. One of his subjects was himself, since he’s been a bike racer for years. A recent scan had revealed that his bones were less dense than usual for a man his age.

Not long after those results came in, he crashed during a race, snapping his collarbone. Six weeks later, in his first post-injury race, he was engulfed by a multi-rider pile-up, crashed again, and re-broke his collarbone.

Worse, he fractured his hip so badly that the ball of the ball-and-socket joint broke off.

“Later I thought, well, this reinforces my study,” he says.

Is cycling bad for the bones? A number of intriguing studies published in the past 18 months, including Smathers’, have raised that possibility — an issue that has special resonance now, with this weekend’s start of the 2009 Tour de France. Certainly, the toll of broken bones among top-level racers is high.

Of course, slamming into the pavement at 40 miles per hour can be expected to break anyone’s bones. But Smathers’ research suggests that other factors may be at work as well.

“If you have low bone mineral mass, you can wind up with a much more serious break from a crash” than if your bones are thicker, he points out.

In his study, the bone density of 32 male, competitive bike riders, most in their late 20s and early 30s, was compared to that of age-matched controls, men who were active but not competitive athletes.

Bone scans showed that almost all of the cyclists had significantly less bone density in the spine than the control group.