V02 max – maximal oxygen uptake. It’s probably the most used and heard acronym in cycling, second only perhaps to FTP – functional threshold power. Just as cyclists obsess over watts per kilogram figures, amateurs and professionals alike also crave a high V02 max.

Three-time Tour de France winner Greg LeMond had a reported V02 max of 92.5 ml/kg/min, incredibly high figures that put him above the elite endurance athlete range of 70 to 85 ml/kg/min. Neither Jonas Vingegaard nor Tadej Pogačar, the two preeminent GC riders of their generation, have ever publicly disclosed their V02 max but one scientific study last autumn calculated that Pogacar’s could be as high as 96 ml/kg/min.

Little wonder he’s the best bike rider in the world.

But how much does a high – or low – V02 max predispose athletic success? How much does it set them up for glory, or hold them back? And when athletes from different sports with supposedly high physiological numbers enter cycling – like French biathlete Émilien Jacquelin who has joined Decathlon CMA CGM’s development team – how much will a high V02 max help them to adapt and then thrive?

“You don’t necessarily need to have a high V02 max to be an elite athlete but it certainly helps,” said Dr Mark Burnley, a senior lecturer in exercise physiology at the University of Loughborough

Understanding V02 max

In understanding why V02 max is such a big topic within endurance sports, Rouleur spoke with Burnley. “V02 max is the maximal rate of which you can inspire, transport and utilise oxygen during whole body exercise,” he said. “And the reason it’s important is that it essentially challenges the respiratory, cardiovascular and muscular systems to work together as a team to get through as much oxygen as possible and utilise it.” The more oxygen your muscles have to operate, the more efficient you will be and the deeper you can go.

Athletes can improve their V02 max, but only within certain parameters because we have a genetically predetermined physiological ceiling from birth that we can’t get beyond. “The reason is simple: the heart gets bigger and bigger and eventually it encroaches on the lungs – there are limits to how the heart’s morphology can change,” Burnley explains. “You can’t just fill the chest up with the heart.”

Tadej Pogačar has an estimated V02 max of 96 ml/kg/min. Photo: Zac Williams/SWPix.com.

Yet one can better their V02 max. “You want the biggest left ventricle possible, so essentially the biggest you can get your heart,” Burnley continued. “You want as many capillaries and mitochondria in the muscles as possible as they’re the power cells in the muscle that use the oxygen to transfer energy from food stuff like carbs and fats into energy cells that can be used.”

A well-trained amateur athlete ought to be happy with a V02 max score of around 50, while elite cyclists, as aforementioned, will expect figures of at least 70. “If you do relatively high intensity training to improve V02 max, you might get a 5-10% increase,” Burnley says. “Someone reasonably unfit doing that sort of training for the first time might see their values change by 20%. But the fitter you are, the ability to improve V02 max goes down.” Why is that? “Mainly because they’ve spent decades training their cardiovascular system so they’re probably already close to their maximal oxygen uptake,” Burnley answers.

Triathlete Kristian Blummenfelt was recorded to have set a V02 max of 101.1 ml/kg/min in January, but Burnley wasn’t so sure if that was indeed the case. “As a rule of thumb, be cautious with measurements over 90, be openly sceptical with anything over 95, and over 100 deserves to be ridiculed. We’re not measuring a horse.” Problems with the machines that measure V02 max is often at fault for such readings – and Norway, where Blummenfelt is from, has been known for excessive V02 max scores. Burnley continued: “90-95 values are probably possible, but above that is unlikely because of the physical size limit of the heart and the ability to perfuse the lung to load up enough oxygen to be able to then deliver that higher rate of oxygen to the muscles to be utilised. 

There’s a reason, therefore, why pro cyclists don’t fixate over their V02 max number as some might think. “There are other aspects of endurance performance we’re more interested in,” Burnley says. “You need a high v02 max to be an elite athlete, but it doesn’t guarantee success as other things come into it. The big three are: V02 max, lactate threshold and critical power, and efficiency and economy.”

Lactate threshold, Burnley explains, is basically the size of one’ engine. “It’s your rev gauge which tells you when you’re entering the red zone and when you’ll start doing damage to yourself.” Critical power is the one cyclists should be most focused on. “It determines if you’re riding in a steady state or not. We see the data in Grand Tours: cyclists are exercising close to or above their critical power, eking out what they’ve got left, on the mountain stages. But the reason you don’t usually see them attack until 3-4km until the end is that there’s a finite amount of work you can do above critical power. And once that’s gone you basically blow. So you have to time it right.” Being economical relates to “how much oxygen you require to maintain critical power output. The less oxygen you can use for a given power output, the better you can perform.”

The Grand Tours visited Europe’s highest roads, where rarefied air makes performance even more difficult. Photo: Zac Williams/SWPix.com

All of which is to say, if a cyclist’s V02 max is towards the low end of the spectrum, it doesn’t spell disaster. “You might have a very high lactate threshold or have a very low oxygen cost of exercise. These things compensate for a lower V02 max.”

How much does V02 max predict elite performance?

With that in mind, how much does an athlete’s V02 max forecast success in cycling? “It’s a great question that a lot of people ask but it’s hard to predict because of all of those parameters,” Burnley says. “If you have a V02 max of 85, which is what Chris Froome had, then you could say that you too should be able to win a Grand Tour. But that’s not a guarantee. The best way to look at V02 max is as a passport to potential success.”

A number of athletes have successfully taken up cycling later in life, with four-minute runner Mike Woods the most obvious example from athletes, and Primož Roglič famously ditching ski jumping to become a five-time Grand Tour champion in cycling.

German skier Anton Palzer made the switch from ski mountaineering to professional cycling with Bora-hansgrohe in 2021. Palzer had a reported V02 max of 92 and went on to spend five years in the WorldTour peloton before returning to skiing this past winter. Palzer didn’t, however, become a race winner in cycling. It’s a lesson for biathlete Jacquelin now of Decathlon’s development squad for whom there is great intrigue as he transitions to bike racing.

“An athlete might have great parameters, but maybe they can’t handle a training block in their new sport. Or maybe they struggle to integrate into their new team,” Burnley says. “There are many things which go into making a cyclist: physiological, psychological and logistical factors will all determine if you end up on the podium. If that wasn’t the case we’d be handing out medals in the lab, and where’s the fun in that?”