BOB HIRSHON (host):
How sled dogs keep going….I’m Bob Hirshon and this is Science Update.
The Iditarod is a grueling dogsled race across 1131 miles of Alaskan snow. But according to exercise physiologist Michael Davis of Oklahoma State University, it’s common to see dogs trot across the finish line without any sign of fatigue.
MICHAEL DAVIS (Oklahoma State University):
The dogs would be perfectly happy to keep on going. And for all appearances, they could do that indefinitely.
So how do they do it? Davis explains that on the first day of the race, the dogs have metabolic responses similar to human endurance athletes. Their bodies burn fat, increase glucose production, and then draw on energy reserves within the muscles themselves. But unlike humans, as the race progresses, the dogs actually start to replenish those reserves while they’re exercising. Davis and his colleagues are now trying to uncover the mechanism behind this impressive metabolic feat. I’m Bob Hirshon, for AAAS, the science society.