Riders in the Tour de France are not only tremendous competitors, they are huge eaters, collectively polishing off enough food to feed a small village – more than 20 million calories – just to stay in the race, according to a fitness and nutrition researcher.

“That’s about the same as 72,000 cheeseburgers,” said Conrad Earnest, Ph.D., of the Pennington Biomedical Research Center.

“The riders have been in the saddle for more than 80 hours at full tilt,” Earnest said, “Each day, they put out more energy than it takes to run a marathon. So the 20-stage tour is like 20 marathons in a row, and to gain the necessary energy, each rider needs to eat the equivalent of 25 cheeseburgers a day to keep from losing too much weight, which ultimately hurts performance.”

Earnest, who is an avid biker himself, was invited to share what he’s learned about the energy needs of the racers themselves. He spoke to The Tour the night before its first stage in London, and has since returned to his fitness and energy research lab at the Center.

He is adept at calculating energy needs and energy output of modern Tour riders as well as gleaning the same information from historical rides.

“Today’s rider is putting out just about the same amount of energy as early riders, but today’s riders have much better equipment and support.” Earnest said, “The first racers rode 50-pound bikes that had only one gear. The racers could not use any assistance and did not stop at the end of each day. If their bike broke, they had to fix it or drop out, and they had to find their own food and drink along the way.”

Today, racers train and travel in teams with large support groups and provided snacks and meals. Each rider will consume, on average, 119,000 calories during the race (about 340 cheeseburgers). But all that food, according to Earnest, is ultimately converted to energy.

“Each rider is generating about 250-350 watts per minute,” Earnest said, “That’s about one-and-a-half million total watts per rider so far.”

So what does that mean?

“With an estimated 1 million people lining the course each day,” Earnest figures, “that’s enough power to run all their ipods, portable TV’s, and radios they bring with them to track the action – with enough left over to cook everyone’s dinner before they go home.”