But not all of the energy a Tour de France cyclist puts into his bike gets turned into forward motion. Cyclists battle air resistance and frictional losses between their wheels and the road. They get help from gravity on downhills but they have to fight gravity while climbing.
I incorporate all of the physics associated with cyclist power output as well as the effects of gravity, air resistance and friction. Using all that, I estimate that a typical Tour de France winner needs to put out an average of about 325 watts over the roughly 80 hours of the race.
Top Tour de France cyclists who complete all 21 stages burn about 120,000 calories during the race – or an average of nearly 6,000 calories per stage. On some of the more difficult mountain stages – like this year’s Stage 12 – racers will burn close to 8,000 calories. To make up for these huge energy losses, riders eat delectable treats such as