Cycling the calcium away

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. . .

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. Some of the racers, young men in their 20s, had osteopenia in their spines, a medical condition only one step below full-blown osteoporosis."To find guys in their twenties with osteopenia was surprising and pretty disturbing," Smathers says.

From the NY Times.

I'm not totally surprised by this. Competitive cycling is one of the toughest sports imaginable, one that really takes its toll -- even without the added issue of doping and its side effects. As the article notes, serious cyclists routinely lose prodigious volumes of sweat while burning more calories than they can consume. It's a form of starvation, and what remains to be seen is if better nutrition will be enough to set things right.

But no reason to worry for anyone other than hard-core cyclists. As the article notes, "In another study, triathletes added moderately to their bone mass over the course of a season." And, intriguingly:

Some researchers theorize that calcium must be taken during exercise to be most effective. A 2004 laboratory study of cyclists who were given either tap water or calcium-enriched water during a 50-minute, stationary-bicycle ride found that the riders drinking the tap water had much higher levels of blood chemicals related to bone loss than did the riders swigging the calcium.

Gatorade, the old standby, contains potassium and sodium but not calcium. After reading this, I may start taking at least some of my usual daily calcium supplements right before a workout.

Posted by David on July 3, 2009 9:36 AM