VO2 Max by Age: The Real Numbers — and Why the Same Person Scores 4.5 Lower on a Bike
Here are the numbers, and then the three things that move your place on them before you have done a single session.
The American reference standard for VO2 max comes from the FRIEND registry: 22,379 tests, 34 laboratories, every state except Alaska, Nebraska and Wyoming, all of them measured properly — mask, treadmill or bike, increasing difficulty until the person could not continue. [1]
VO2 max is the most oxygen your body can take in and use in a minute, per kilogram you weigh, flat out. It is written in mL/kg/min and there is no everyday American unit for it, so it stays as the researchers write it.
The table
| Percentile | 20–29 | 30–39 | 40–49 | 50–59 | 60–69 | 70–79 | 80–89 |
| 90th | 58.6 | 55.5 | 50.8 | 43.4 | 37.1 | 29.4 | 22.8 |
| 50th | 46.5 | 39.7 | 35.3 | 29.2 | 24.6 | 20.6 | 17.6 |
| 10th | 28.6 | 24.9 | 22.1 | 18.6 | 15.8 | 13.6 | 12.9 |
| Percentile | 20–29 | 30–39 | 40–49 | 50–59 | 60–69 | 70–79 | 80–89 |
| 90th | 49.0 | 42.1 | 37.8 | 32.4 | 27.3 | 22.8 | 20.8 |
| 50th | 36.6 | 28.3 | 25.7 | 22.9 | 19.6 | 17.2 | 15.4 |
| 10th | 22.5 | 18.6 | 17.2 | 16.5 | 13.4 | 12.3 | 11.4 |
Find your row, find your decade. The 50th percentile is the ordinary middle — half of the people tested came in above it and half below. The 90th and 10th are there so you can see the spread, which is wide: among men in their forties, the top tenth start at 50.8 and the bottom tenth finish at 22.1. [1]
That is the answer to the question. Now the part no chart tells you.
1. Which machine you were on is worth 4.5
In the same registry, treadmill results run 22%, or 4.5 mL/kg/min, higher than cycle results. [1] Not because those people were fitter — because cycling uses less muscle mass than running does, and the test finds a lower ceiling.
So a bike-derived number read against a treadmill chart understates you, by roughly as much as a hard training block is worth. A few months of intervals adds about 5.5. Reading the wrong column can cost you the whole thing on paper.
The tables above are treadmill values. If you were tested on a bike, the paper has a separate set and you want those.
2. Which edition of the chart you found
This is the one that surprised us, and we checked it by putting the two published tables side by side rather than taking a sentence on trust.
| 50th percentile | 2015 | 2022 | Change |
| Men 20–29 | 48.0 | 46.5 | −1.5 |
| Men 70–79 | 24.4 | 20.6 | −3.8 |
| Women 20–29 | 37.6 | 36.6 | −1.0 |
| Women 70–79 | 18.3 | 17.2 | −1.1 |
The standard moved down. A man in his seventies who scored 22 was below the middle on the 2015 chart and comfortably above it on the 2022 one. Same person, same lungs, different edition.
And here is the sentence that has to come with it, because leaving it out would manufacture a story that is not there. The authors say the drop is “unlikely to be due to decreases in CRF over the years” — rather, the newer values “may more accurately represent” the country. [1]
Look at why. The 2015 standard came from 8 laboratories and 7,783 tests. The 2022 one came from 34 laboratories and 22,379. [1][2] The chart did not change because America got less fit. It changed because somebody finally measured enough of America. That is what a reference standard getting better looks like, and it is the opposite of the decline story the numbers could be made to tell.
3. Whether anybody actually measured you
Every number above came off a gas analyser. The number on your wrist is a model — a guess assembled from your heart rate and your pace.
When the Apple Watch Series 7 was checked against laboratory equipment, the agreement statistic came out at 0.47, which the authors classify as poor, with a typical error of 8.85 mL/kg/min. [6] That study ran nineteen people, which is small and we are not going to pretend otherwise.
But hold 8.85 against the table above. Among men in their forties, 8.85 is most of the distance from the 50th percentile to the 90th. The sibling page goes through the watch evidence properly, including the fair defence of it. The short version for this page: do not put a wrist estimate into a chart built from gas analysers and believe the percentile that comes out.
Why anyone built these charts at all
In 1989 Steven Blair and colleagues published a study in JAMA following healthy men and women and reporting that low fitness predicted dying earlier. [4] That paper is the reason this field exists, and the FRIEND papers open by citing it. [1]
The evidence since has become very large: an overview of 26 systematic reviews, 199 cohorts and 20.9 million observations, puts the risk of dying for high-fitness people at roughly half that of low-fitness people. [5] In 2016 the American Heart Association went as far as a formal statement arguing fitness should be treated as a clinical vital sign, alongside blood pressure. [3]
That statement is why reference standards exist at all — a vital sign is useless without a normal range to read it against. It is also, downstream, why a wearable on your wrist now shows you a number, and why a testing appointment can be sold to you as a longevity service.
The association is real and it is not a promise. Those cohorts compare fitter people with less fit people; the certainty the reviewers themselves attach to that evidence runs from very low to moderate. [5] How we grade this kind of evidence.
What the chart cannot do
Four limits, all of them stated by the people who built it. [1]
— It is American. The authors say plainly that fitness differs between countries and that these values should be applied cautiously outside the US.
— “Apparently healthy” is doing some work. People with heart disease and lung disease were excluded, but the authors note the remaining group still included people with diabetes, obesity and joint problems.
— The oldest band is thin. The 80–89 group is 358 people, 1.6% of the whole registry.
— The tests span 1968 to 2021. A current reference standard contains measurements taken more than fifty years apart.
None of that makes the table wrong. It makes it a reference, which is a different thing from a verdict on you.
What to do with your number
Two honest uses, and one bad one.
Useful: compare yourself to your own previous properly-measured number. And note which decade band you sit in, because the gap between bands is about 4.0 — roughly what a training block moves.
Not useful: comparing your watch’s number to somebody else’s watch, or to a chart whose edition, machine and population you cannot name. That is three unknowns stacked on an estimate.
Fitness is unusual because it is one of the few things measured about you that you can also change. Grip strength predicts a lot and squeezing a gripper does not fix it. This one moves. So does the simplest version of doing more.
And the thing being sold is the measurement. The table above is free, the paper it came from is open access, and the part that actually changes your row is being out of breath on purpose, regularly.
