If you train, run, ride a bike, or simply want to know how your body responds to effort, understanding what your VO2 max really means can help you train better… and stop worrying about a number that, on its own, doesn’t tell the whole story.
What exactly is VO2 max?
VO2 max is the maximum amount of oxygen our body can take in, transport, and use during high-intensity exercise. It is considered one of the best indicators of aerobic capacity.
When we exercise, we breathe oxygen, which passes into the blood and is carried to the muscles. There it participates in the processes that allow energy to be produced to sustain physical activity. The greater the body’s ability to use oxygen, the greater, in principle, our capacity to sustain intense aerobic efforts. It is expressed in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min). Therefore, in general terms, a high VO2 max is usually associated with good cardiorespiratory fitness. But there’s an important word: “generally”.
Because having a high VO2 max does not guarantee that you are the best runner, cyclist, or athlete. Performance also depends on factors such as movement economy, lactate threshold, strength, technique, experience, and the ability to maintain a certain percentage of VO2 max for a long time.
So, what VO₂ max is good?
Here begins the problem with tables. VO2 max depends on age, sex, training level, body mass, body composition, and other factors. Therefore it doesn’t make much sense to claim there is a single figure that separates a “good” VO2 max from a “bad” one.
As a very general reference, in adults values can be found roughly between 30 and 60 ml/kg/min, though there is enormous individual variability. In trained athletes, values can be considerably higher.
For recreational athletes, for example, the reference text typically places trained men around 50-60 ml/kg/min and trained women around 45-55 ml/kg/min, while high-level athletes can far exceed those figures.
But beware: a value of 50 doesn’t mean the same at 25 as at 55 years old, nor does it have the same meaning in an athlete as in a sedentary person. The most useful comparison is therefore with yourself.
VO₂ max is not a genetic sentence
There’s a widely held idea: “my VO₂ max is low because I’m not genetically built for running.” The reality is much more interesting. Training can substantially improve VO2 max, but not everyone responds the same way to the same program. The HERITAGE study found enormous variability in response to endurance training: after a 20-week program, some people hardly improved while others showed very significant increases. The authors also estimated a substantial genetic contribution to that variability.
What does this mean for you?
If after a few weeks of training your VO2 max hasn’t risen as fast as you expected, it doesn’t necessarily mean you’re doing something wrong. You may need to change the type of stimulus, adjust the training load, or simply give the process more time.
And there’s another good news: you can improve aerobic capacity at almost any age, though the rate of adaptation changes with age.
Can I trust the VO₂ max on my watch?
Yes… but with caveats. This is probably the most important part for anyone training with a Garmin, Apple Watch, Polar, Suunto, or another sports device. The true VO₂ max is determined through a gas-analysis exercise test. The athlete performs progressive exercise—typically running on a treadmill or cycling—while breathing through a mask that allows analysis of oxygen consumption and other parameters.
The watch, on the other hand, does not directly measure the oxygen you are using. It makes an estimate based on variables such as heart rate, pace, movement, and other data. Therefore you should not interpret that a value of 51 necessarily means your lab VO2 max is exactly 51. Wrist-device estimates can have appreciable errors compared with lab measurements.
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Dylan Holloway
I’ve always been fascinated by the stories hidden behind a stopwatch, a finish line or a record-breaking performance. At Athletics News, I cover athletes, competitions and the moments shaping track and field, with a particular interest in the people and journeys behind the results.