This report originally featured in The Dialogue.
John Eric Goff is a professor of Physics, University of Lynchburg.
Imagine you get started pedaling from the start of Phase 17 of this year’s Tour de France. To start with, you would bicycle around 70 miles (112 km) with a gradual raise in elevation of all around 1,300 feet (400 m). But you’ve nevertheless to hit the enjoyment component: the Hautes-Pyrénées mountains. In excess of the following 40 miles (64 km) you would have to climb 3 mountain peaks with a net raise of a mile (1.6 km) in elevation. On the fittest working day of my daily life, I may possibly not even be ready to finish Stage 17—much significantly less do it in anything remotely near to the 5 several hours or so the winner will get to finish the trip. And Phase 17 is just a single of 21 levels that should be finished in the 23 days of the tour.
I’m a sports activities physicist, and I’ve modeled the Tour de France for just about two many years utilizing terrain data—like what I explained for Phase 17—and the guidelines of physics. But I continue to simply cannot fathom the actual physical capabilities needed to complete the world’s most well known bike race. Only an elite couple people are capable of completing a Tour de France stage in a time that’s calculated in several hours as an alternative of times. The reason they are equipped to do what the relaxation of us can only dream of is that these athletes can produce massive amounts of electric power. Power is the charge at which cyclists burn off vitality and the energy they burn off will come from the food stuff they take in. And in excess of the class of the Tour de France, the successful bicycle owner will melt away the equivalent of about 210 Significant Macs.
Biking is a video game of watts
To make a bicycle go, a Tour de France rider transfers electricity from his muscle mass, as a result of the bicycle and to the wheels that thrust again on the ground. The faster a rider can put out electrical power, the higher the energy. This amount of energy transfer is normally calculated in watts. Tour de France cyclists are capable of producing enormous amounts of energy for extremely extended intervals of time as opposed to most men and women.
For about 20 minutes, a match leisure bicycle owner can consistently set out 250 watts to 300 watts. Tour de France cyclists can produce over 400 watts for the exact time interval. These pros are even able of hitting 1,000 watts for small bursts of time on a steep uphill—roughly sufficient power to run a microwave oven.
But not all of the vitality a Tour de France cyclist places into his bicycle receives turned into ahead motion. Cyclists struggle air resistance and frictional losses in between their wheels and the street. They get aid from gravity on downhills but they have to combat gravity when climbing.
I include all of the physics affiliated with bicycle owner electric power output as properly as the outcomes of gravity, air resistance, and friction into my model. Using all that, I estimate that a common Tour de France winner wants to place out an average of about 325 watts about the roughly 80 several hours of the race. Remember that most leisure cyclists would be joyful if they could develop 300 watts for just 20 minutes.
Turning foods into miles
So in which do these cyclists get all this electrical power from? Food items, of class.
But your muscle tissue, like any device, cannot change 100% of food items electricity right into strength output—muscles can be any place between 2 percent effective when made use of for pursuits like swimming and 40 per cent productive in the coronary heart. In my design, I use an average performance of 20 %. Recognizing this efficiency as nicely as the electricity output necessary to acquire the Tour de France, I can then estimate how much foodstuff the profitable cyclist desires.
Top Tour de France cyclists who complete all 21 phases burn off about 120,000 calories through the race—or an average of virtually 6,000 energy for each phase. On some of the much more tricky mountain stages—like this year’s Phase 17—racers will burn off close to 8,000 energy. To make up for these enormous strength losses, riders eat delectable treats such as jam rolls, electrical power bars, and mouthwatering “jels” so they don’t waste strength chewing.
Final year’s winner, Tadej Pogačar, weighs only 146 lbs. Tour de France cyclists do not have much fat to melt away for electricity. They have to keep placing food electrical power into their bodies so they can put out vitality at what would seem like a superhuman amount. So this year, although watching a phase of the Tour de France, take note how several periods the cyclists eat—now you know the motive for all that snacking.