If you train, run, bike, or simply want to know how your body responds to effort, understanding what VO₂ max really means can help you train better… and stop worrying about a number that, by itself, 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’s considered one of the best indicators of aerobic capacity.
When we exercise, we breathe oxygen, which passes into the blood and is transported to the muscles. There it participates in the processes that allow energy production to sustain physical activity. The greater the body’s capacity to use oxygen, the greater, in principle, our ability 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 associated with good cardiorespiratory fitness. But there is an important word: “generally”.
Because having a high VO₂ max does not guarantee 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?
The problem with the tables begins here. VO₂ max depends on age, sex, training level, body mass, body composition and other factors. That’s why it doesn’t make much sense to claim there is a single number that separates a VO₂ max “good” from one “bad.”
As a very general reference, in adults values are typically in the range 30 to 60 ml/kg/min, though there is enormous individual variability. In trained athletes, the values can be considerably higher.
In 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 surpass those figures.
But beware: 50 doesn’t mean the same thing 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 decree
There is a widespread idea: “my VO₂ max is low because I’m not genetically made to run.” The reality is much more interesting. Training can substantially improve VO₂ max, but not all people respond in the same way to the same program. The HERITAGE study found enormous variability in the response to endurance training: after a 20-week program, some people barely improved while others experienced very large increases. The authors also estimated a significant genetic contribution to that variability.
What does this mean for you?
That if after a few weeks of training your VO₂ max doesn’t rise as fast as you expected, you aren’t necessarily doing something wrong. You may need to change the type of stimulus, review the training load, or simply give the process more time.
And there’s another good news: you can improve aerobic capacity at practically any age, although 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 sport device. The real VO₂ max is determined through a gas analysis exercise test. The athlete performs progressive exercise—usually running on a treadmill or pedaling—while breathing through a mask that allows analysis of oxygen consumption and other parameters.
The watch, by contrast, does not measure directly the oxygen you are using. It estimates it from variables such as heart rate, pace, movement, and other data. Therefore you should not interpret that a value of 51 necessarily equals your lab VO₂ max of 51. Wrist‑based estimates can show appreciable errors compared with laboratory 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.