Kristian Blummenfelt has become the first athlete known to record a laboratory VO2 max above 100. The Norwegian recorded a value of 101.1 millilitres of oxygen per kilogram of body weight per minute, a figure revealed on 28 January 2026 and, by the data on the screen, the highest ever measured under laboratory conditions.
The moment arrived quietly.
Blummenfelt shared footage of the test on Instagram, showing himself running on a treadmill while wearing a respiratory mask as oxygen consumption was measured, with the final slide showing the result clearly.
A series of slides posted by Blummenfelt included a clip of the Norwegian in the aftermath of his treadmill test, sucking air through his ventilation mask, before the camera panned to the computer screen revealing the 101.1 reading.
He offered no commentary. The number spoke.
The mark did not appear from nowhere.
During the week of 19 to 25 January, he logged just over 25 hours of training and covered approximately 304 kilometres across swimming, cycling and running around Bergen, Norway.
One day included a 105-kilometre ride with 1,730 metres of elevation gain, followed by a 16-kilometre run later the same evening.
This was no isolated laboratory experiment.
Blummenfelt was not posting the figure in an off-season test; he was in full training, logging weeks of 25 hours or more, and continuing to race at the top level of the sport.
The measure of a threshold
To read the number is to grasp its scale.
VO2 max is a measure of how much oxygen the body can take in and use during maximal effort exercise, reflecting the combined capacity of the lungs, heart, blood and muscles to transport and use oxygen.
Above it stood one name.
Before Blummenfelt's test, the highest widely cited VO2 max belonged to Norwegian cyclist Oskar Svendsen, who recorded a value of 97.5 at age 18, before retiring from professional cycling due to heart rhythm issues.
Blummenfelt cleared that mark comfortably.
Laboratory-verified values above 90 are unusual, and crossing 100 placed him in a category that, until now, had effectively consisted of one retired cyclist.
The reading did not pass without challenge.
Team UAE performance co-ordinator Jeroen Swart led a chorus of top physiologists questioning the record figure, writing on X that someone should teach the Norwegian physiologists to calibrate a metabolic cart, and that dodgy VO2 data seemed to surface every second year.
Yet the doubt sits alongside a body of evidence.
The test aligns closely with what has been visible in competition for years — an athlete able to sustain high outputs late in races, run sub-2:40 marathons off the bike, and recover quickly enough to repeat the effort.
An engine, still rising
What sets this apart is age. Blummenfelt turned 32 in February.
The biggest difference between Svendsen in 2012 and Blummenfelt is age: Svendsen was 18, while Blummenfelt is 32 with his VO2 max still rising at a time when it is traditionally supposed to be falling.
The result reads less as raw potential than as accumulation.
The career behind the number is already complete on its own terms. He won Olympic gold in Tokyo, took the World Triathlon short-course crown in the same season, and broke the championship record on his full IRONMAN debut at St. George in 7:49:16. In June 2022 he became the first human to complete an IRONMAN-distance triathlon under seven hours. Yet 2025 left work undone.
He won the 2025 IRONMAN Pro Series, earning a season bonus, but missed both world titles, finishing third at the IRONMAN World Championship in Nice and runner-up at the 70.3 World Championships in Marbella.
The medals measure what he has done. This number measures what remains possible.
