Scientists analyze Tadej Pogacar’s Tour de France climbs to measure the limits of human endurance

The official record for highest VO2 max belongs to a former cyclist named Oscar Svendsen, whose brief career I wrote about in 2019. VO2 max is a measurement of how much oxygen your lungs, heart and muscles can use to fuel your metabolism; If you want a single number to measure your aerobic fitness, this is what you use. At age 18, Svendsen could use 96.7 milliliters of oxygen per minute per kilogram of body weight, one of the only laboratory-verified readings above 90. Two years later, after a distinguished stint with a minor Norwegian pro team, he left cycling for good.

There are a few different ways to interpret this parable. One is that VO2 max has been overrated as a predictor of success. Svendsen himself takes more or less the same approach. “Talent is based on patience and the ability to perform over time,” he said. told weekly cycling When they tracked him down earlier this year, 12 years after his retirement. “The physical is a bonus.” Another is that the measurement was odd or the machine was incorrectly calibrated, a possibility often raised for ultra-high VO2 max scores (like Instagram report only Triathlete Christian Blumenfelt recorded 101.1 ml/kg/min earlier this year).

A third option is that laboratory tests do not accurately reflect real-world conditions. Sure, you can pedal harder on a stationary bike because a scientist tells you to do so – but are you really digging as deep as you can when you’re trying to smash your rivals on a major Tour de France climb? And are you using the same muscles and movement patterns on the stationary bike as well? If we really want to understand the upper limits of human capacity, wouldn’t it be better to analyze real-world threatening demonstrations?

This is the approach in the upcoming study International Journal of Sports Physiology and PerformancePedro Valenzuela of the University of Alcalá with colleagues Sebastian Sitko and Ole Kristian Berg. They take real-world race data from the most dominant cyclist of our time, Tadej Pogačar – who, barring disaster, will soon win his fifth Tour de France title – and come up with an estimate of your VO2 max. Their conclusion: It’s on par with Svendsen’s off-the-charts numbers, and probably even exceeds it.

How did they estimate Pogsar’s VO2 max

Grand Tour stages are several hours long and most are ridden well below VO2 maximum. The moments of truth come on brutal climbs up mountain passes, where heroes are made and contenders exert near maximum effort continuously for 40 minutes.

If you have a power meter on one of these climbs, you can get a good estimate of your VO2 max. Let’s say you’re climbing Perragudes, a pass in the French Pyrenees, and you manage to maintain an average of 476 watts for the duration of the climb:

• Watt is a measure of energy per time: 476 watts is equivalent to burning 6.8 calories per minute. That’s how much energy it takes to move your pedals.
• But humans are not completely efficient. When you burn one calorie of food energy, about a quarter of it (on average, 23 percent for elite cyclists) goes into turning your pedals while the rest is wasted as heat. So if you’re using 6.8 calories per minute to rotate your pedals, you actually need to burn 29.7 calories of food energy per minute.
• Oxygen is required for the metabolic reactions that convert food energy into muscle contraction during aerobic exercise. In fact, they require a predictable and consistent amount of oxygen. To burn 29.7 calories per minute you need 5.73 liters of oxygen per minute.
• If (like Pogacar) you weigh 66 kilograms (145 pounds), that means you’re burning 86.8 milliliters of oxygen per minute per kilogram of body mass.
• But this is still not your VO2 max, because Peyragudes is too long to run at maximum power. When Pogasar rode it in the 2025 Tour de France, he clocked 17 minutes and 19 seconds. For climbs of that duration, typical cyclists can typically tolerate about 92 percent of their actual maximum, meaning Pogsar’s VO2 max is 94.3 ml/kg/min.

There are a lot of assumptions out there. That could be a little more or less efficient than 23 percent. He might be able to maintain a VO2 max slightly higher or lower than 92 percent for a 17-minute climb. His weight that day would not have been exactly 66 kg.

And there’s a more serious challenge: Pogsar doesn’t make its electricity data public. So we don’t know that his average on that climb was 476 watts. Instead Valenzuela and his colleagues simply have to estimate average strength based on how high the climb is and how long it takes. With some assumptions, you can estimate how much energy was required to overcome gravity (397 watts), air resistance (45 watts), and the rolling resistance of the tires (13 watts), and you can make further adjustments for factors like high altitude. Thus they came up with an estimate of 476 watts.

You might think this process is doomed to inaccuracy, but they tested it on old data from former Grand Tour winner Chris Froome, who famously released some of its power data And laboratory test In an attempt to suppress doping rumors. Valenzuela’s real-world estimate for Froome’s VO2 max is 85.3 ml/kg/min, which is remarkably close to Froome’s published laboratory value of 84.4 ml/kg/min.

In total, Valenzuela and colleagues analyzed four recent climbs of Pogasar, which ranged from 17 to 40 minutes: the Plateau de Baile and Isola 2000 from the 2024 Tour de France; Paragudes from the 2025 Tour de France; And the Rhino from the 2025 Tour of Lombardy. VO2 max estimates were 96, 97, 94, and 98 ml/kg/min, respectively, for an overall average of 96 ml/kg/min—exactly like Oskar Svendsen. If you play with assumptions, for example imagining that he is unusually efficient or inefficient, you can get a range of VO2 max predictions between about 90 and 102 ml/kg/min.

What does it mean

For a long time, Svendsen’s record was not in line with other readings. Cross-country skiing legend Björn Dahli’s previous “record” of 96 ml/kg/min, which he broke, was only reported in a newspaper rather than a scientific journal. One version of the story I’ve heard is that he suspected the measure was probably off the table, but decided to air it anyway to irritate Dehli’s opponents.

Other ultra-high measurements often accompany the same stuff, which is why there was a lot of skepticism when Blumenfelt shared an Instagram photo with a VO2 Max machine showing a clear score of 101.1. Valenzuela’s new analysis doesn’t tell us what Pogsar’s VO2 max is, but it does tell us that he Sure Live in that mid- to late-nineties neighborhood – and possibly even longer, as Valenzuela’s beliefs were generally conservative. This means that these other skyrocketing readings are plausible, not necessarily measurement error.

Of course, I believe Pogsar has had his VO2 tested at a lab. I would love to see the results of those tests, needless to say. But it’s probably best that Pogacar and most other world-beating athletes keep their lab data secret. You want to be remembered as the person who won the race, not as the person who had the physical ability to win the race. Just ask Oscar Svendsen.

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