"It allows us to evaluate what was subjective at the time": the wattage revolution, this data that has invaded the Tour de France peloton

It was Kévin Vauquelin, after the Caen time trial on July 9, who said : "As soon as there was an audience, I saw my watts rising." It was Warren Barguil who, to testify to the speed on the Rançonnière hill , on the road to Vire (last Thursday), said he had achieved "close to a watt record." It was Matteo Jorgenson who, on the morning of the Puy de Sancy stage (Monday), predicted "a festival of watts." Finally, it was Jonathan Vaughters, manager of EF Education-EasyPost, who said he had carried out a comparative analysis between Ben Healy and Quinn Simmons during their breakaway on the roads of Auvergne: "Ben produced 75 watts less over the duration of the stage, it's remarkable, it shows how aerodynamic he is."

This isn't the first time the cycling community has taken up a scientific term, but the place occupied by watts in everyday life and in the peloton's discourse is unparalleled. They are everywhere. In every calculation of position, equipment, and clothing. On the Strava or Instagram accounts of the riders, like Wout Van Aert, who posted a screenshot of his ten-minute record during the Giro d'Italia (518 W) . And also on the social networks of certain cycling observers who, this Thursday, at the end of the climb to Hautacam and as for every mountain stage for several years, will attempt to estimate the power developed by the favorites of the general classification, and draw conclusions on the "normality" of their performances.

"It allows us to evaluate what was subjective at the time, when runners listened to their feelings."

Watts have revolutionized the way we analyze performance. Km/h no longer count, and minutes are only an indicator of difference. "Watts are the most factual expression of a runner's energy expenditure and athletic performance, because they are not impacted by the environment, weather, or wind speed, as Km/h can be," explains Jean-Baptiste Quiclet, Performance Director at Decathlon-AG2R La Mondiale. "It allows us to evaluate what was subjective back then, when runners listened to their feelings, simply calling a race easy or difficult," explains Maxime Robin, his counterpart at TotalEnergies. "Now, with sensors, we can measure the efforts made."

First appearing in the 1990s, watts reached all levels of the peloton between 2010 and 2012, when the first reliable sensors arrived on the market. Placed on the crankset, they measure the deformation with each pedal stroke, and can thus determine the force exerted by the rider. Multiplied by the cadence (the number of pedal strokes), this gives a power value, which is therefore expressed in watts and displayed in real time on the riders' computers.

In races, usage varies from person to person. While Barguil looked at how hard he pushed at La Rançonnière, others pay less attention. "I prefer to run with my feelings," says Matteo Vercher (TotalEnergies). "When you really have to manage an effort, I try to look," says Alex Baudin (EF Education-EasyPost). "But you don't always have time when you're going flat out. On the other hand, I like to analyze afterwards, using Strava segments, comparing myself with others. And we use them a lot in training."

This is where, in the eyes of the riders and their coaches, watts matter the most. "With this data," explains Maxime Robin, "we evaluate the riders' profiles as well as the races according to their power requirements, and then we plan the sessions." While the peloton of the 2010s may have balked at the introduction of watts, now even the least scientific riders have fully embraced power data. Everyone knows their watt records at their fingertips over various durations, and also understands the needs of different levels of competition.

"The World Tour level is 1500-1700 watts over one to five seconds for a sprinter," says Jean-Baptiste Quiclet. "A puncher will be around 1,000 watts over thirty seconds. A puncher-climber can be over 500 watts over three minutes..." "We all know each other very well, but we also know that the data varies with fatigue," says Baudin, who excelled in the breakaway that allowed his leader, Healy, to take the yellow jersey on Monday. "You can't produce the same power after the tenth day of racing, and I felt it in the breakaway, there was fatigue in the legs."

"It's because each rider knows their thresholds that we often have race scenarios where the peloton moves forward at a steady pace, without much happening until the last hour."

This is why "the trendy concept," according to Quiclet, is to determine power records by taking into account different levels of fatigue. "We were forced to define this because we realized that many runners were at a similar level when they were fresh, while only one of them won. This means that there is an interaction with the energy expended beforehand. In fact, each runner does not have a single power profile, but power profiles depending on the energy expended throughout the race. So a five-minute record after 2,000 kilojoules expended, after 3,000 kilojoules, etc."

So much data will make even the oldest riders, like Bernard Hinault, shudder with disgust, who hates the idea that sensors can replace tactical sense and panache. It's undeniable that watts influence race behavior. "It's because each rider knows their thresholds that we often have race scenarios where the peloton advances at a steady pace, without much happening until the last hour," notes Quiclet. "Then suddenly, when many have burned their available energy, the best accelerate and it explodes everywhere." But this lively start to the Tour also shows that modern cycling isn't straitjacketed. As if their detailed knowledge of their wattage potential showed the riders, mirroring their limits, what they're capable of.