Tour de France Femmes Power-to-Weight Data

The Tour de France Femmes provided eight spectacular days of racing, finishing on the brutally steep Super Planche des Belles Filles. Here we take a look at the power it took for the best riders in the world to finish strong and place well in the first women's Tour de France to be held since the ’80s.

For climbing days, a rider's power-to-weight ratio is the critical factor. Yes, tactics, drafting, and positioning play into the dynamics of racing. But when push comes to shove on a sharply uphill finish, it all comes down to how many watts per kilogram a rider can produce, and for how long.

The final stage 8 of the Tour de France Femmes finished on La Super Planche des Belles Filles, a 4.3mi climb that averages 8.7 percent and gains nearly 2,000 feet.

Racing in the yellow jersey, Annemiek van Vleuten (Movistar) charged alone to win the stage by powering up the climb in 24 minutes at a VAM (vertical meters per hour) of 1,509.  Van Vleuten does not publish her power data, but a ballpark estimate would put her output at an average of 5.45 watts per kilogram. 

Nina Buijsman and Annemiek van Vleuten during stage 8 of the Tour de France Femmes. Photo: Luis Angel Gomez/Sprint Cycling Agency

Nina Buijsman of Human Powered Health does publish her power data, and she averaged 247 watts for 30 minutes and 11 seconds. This represents 4.5w/kg for Buijsman, who finished 21st on the day to end the Tour in 25th overall. Her VAM was 1,200.

Dr. Andrew Coggan detailed the upper limits of what is possible for female and male cyclists in his Power Profile Chart, which breaks down w/kg power for 5-second, 1-minute, 5-minute and function threshold durations. This chart features nine categories of athletes, from Novice to World Class. For women, Coggan's chart sets the absolute high water mark at 5.69w/kg for threshold power. 

"It's important to note that in Dr. Coggan's chart, each one of these numbers represents the absolute best effort done in perfect conditions," said FasCat Coaching founder Frank Overton, who collaborated with Dr. Coggan for many years on power-training research and application.

"For example, these numbers represent an effort where a rested athlete warmed up and then completed the target duration," Overton said. "Doing an effort totally fresh, and doing a 30-minute effort at the end of a hard stage at the end of the hardest stage race in the world are totally different things!"

Nina Buijsman just after the finish of stage 8 of the Tour de France Femmes. Photo: Luis Angel Gomez/Sprint Cycling Agency

For Buijsman, for instance, her 30-minute 4.5w/kg effort came at the end of a stage where she had already racked up 2,245 kilojoules. 

What's a kilojoule, you say? The basic formula is this:

1 watt = 1 joule applied for 1 second
1,000 joules = 1 kilojoule (KJ)

Therefore, kilojoules = watts X seconds / 1,000

Juliette Labous (Team DSM) finished fifth on the Super Planche stage, averaging 282 watts for 25:56 with an average heart rate of 174bpm. Based on a published weight of 54kg, this puts her effort at 5.22w/kg. Her VAM for the climb was 1,397. Labous ended the race in fourth overall, behind van Vleuten, Demi Vollering (SD Worx), and Kasia Niewiadoma (Canyon-SRAM). 

If you are a Strava subscriber, you can look at the times of the Tour de France Femmes riders up the Super Planche climb here. Interestingly, the men's Tour de France also used this finishing climb this year, so by toggling between Women and Men on the Strava Leaderboard you can compare their times, VAMs, and power (if listed).

"A lot of bike riders wonder what it takes to race at the highest level in the world," Overton said. "Some of the more talented and hardworking riders might even look at the numbers from the Super Planche finish and think, 'I could do that.' But again, doing a 20- to 30-minute all-out effort fresh is one thing, but doing 4.5 watts per kilo or more at the end of a very hard stage at the end of a very hard Tour de France Femmes... that takes a world-class athlete."

Want to see how your current power to weight ratio stacks up? We've got a handy calculator for you here. Just take your best 20-minute power and divide by your body weight in kilograms. (Get your kg weight by dividing your weight in pounds by 2.2.) 

"And if you really want to compare," Overton said, "go out and race for 2,250 kJs on the eighth day of a training block!"