The The Tour de France 2022 is here. Beginning in Copenhagen on July 1, the tour covers nearly 2,100 miles (3,380 kilometers) more than 24 days of cycling through Denmark, Belgium, Switzerland and France. The Tour is a feat of human athleticism, but to truly understand how amazing it is to finish the race – let alone win it – you have to think about a unique blend of physics, biology and physiology. Just mix them up and you have a Tour de France champion.
Over the years, The Conversation has published a series of stories covering the science of the Tour de France and elite athletics. Below are excerpts from three of these stories to help you better appreciate this spectacular race.
1. The biomechanics of the bicycle
Cycling is an easy thing to do once you learn, but the physics of how bikes and riders work together is surprisingly complicated. As Stephen Cain, mechanical engineer at West Virginia University, explains, “A big part of balancing a bicycle is controlling the center of mass of the rider-bicycle system.” Basically, you need to keep the center of mass over the wheels – otherwise you’ll tip over.
“Riders can use two main balancing strategies: steering and body movement relative to the bike,” Cain explains. The steering keeps the bike under you while body movements subtly shift your center of gravity. Cain and his colleagues conducted a study to understand the difference between how novice and professional cyclists balance a bike, and as he says in his article, they found that “novice and expert cyclists exhibit balance performance similar to slow speeds. But at higher speeds, expert riders achieve superior balance performance using smaller but more efficient body movements and less steering.
This small-scale control is why Tour de France riders barely look like they’re riding.
2. How many calories do Tour runners burn?
Think back to the last time you did strenuous exercise and how hungry you were that night. Now imagine how hungry you would be if you had to cycle more than 100 miles (165 km) and climb almost 10,000 feet (about 3,050 meters) of elevation change in less than five hours. That’s what riders will have to do on Stage 12 of this year’s race as they traverse mountain passes across the French Alps. As Eric Goff, sports physicist at Lynchburg University explains, cyclists are going to need a lot of fuel to get there.
“To make a bike move, a Tour de France rider transfers energy from his muscles, through the bike and to the wheels pushing back on the ground,” Goff explains. Professional cyclists are in another league when it comes to generating power with their legs, but they are still limited by basic human biology. “Muscles, like any machine, cannot convert 100 percent of food energy directly into energy production,” says Goff. “Muscles can be anywhere between 2% efficiency when used for activities like swimming and 40% efficiency in the heart.”
With mountains to climb and glory to claim, cyclists must fuel their muscles with food. In his story, Goff calculates that during the Tour de France riders will burn 120,000 calories, the equivalent of about 210 Big Macs.
3. Biology explains why professional athletes are young
When you watch the Tour de France, the FIFA World Cup or the Olympics, it’s common to see a young teenage phenom, but it’s rare for someone over 40 to compete.
Roger Fielding, an aging and exercise researcher at Tufts University, writes that “old people and young people build muscle the same way.” But there’s a biological reason no 50-year-old has ever won the Tour de France: “As you age, many of the biological processes that turn exercise into muscle become less efficient.”
Muscles grow through a number of complicated cellular pathways that are activated during exercise. When this network of receptors and signaling chemicals are triggered, the body responds by increasing muscle size – and even makes small adjustments to active genes. But as Fielding explains, in older people, “the signal telling muscles to grow is much weaker for a given amount of exercise. These changes begin to occur when a person reaches about age 50 and become more pronounced over time.
Many people can reach the best shape of their life when they are in their 50s or 60s. But the fact that it’s harder to get in shape as you age is one of the main reasons why it’s so important for older people to exercise – and why you won’t see any retirees in head of the Tour de France peloton.
