VO2 Max by Age: What's a Good Score for Men and Women?
A good VO2 max isn't a single number. It rises and falls with age and differs between men and women, so the same score that's excellent at 55 can be ordinary at 25. What counts is where you sit for your own age and sex.
This page covers what counts as a good VO2 max by age and sex using the ACSM percentile tables, an interactive tool to find your percentile and fitness category, how much to trust your watch's estimate against a lab test, why VO2 max declines with age, and what the research connects to changing it.
"Is my VO2 max good?" is the question, and the honest answer is that it only makes sense against your age and sex. A 38 is excellent for a 60-year-old woman and unremarkable for a 25-year-old man. VO2 max, the maximum amount of oxygen your body can use during hard exercise, is one of the most useful single numbers a wearable gives you, and one of the most age-dependent. It peaks in your twenties and declines steadily from there, faster if you're sedentary, slower if you train. So a score is only meaningful next to people like you.
The tool places your number against the ACSM reference percentiles for your age and sex, and the table beneath shows the full set. One caveat up front: these are lab-test values, and your watch only estimates VO2 max. We come back to how much that matters.
Enter your age, sex, and the VO2 max your watch or a test gave you. We place it against the ACSM percentile tables for your age and sex. We show where your score sits. What it means for you depends on your goals, your history, and your trend over time.
Fill in all three to see where your score falls.
Reference values: ACSM's Guidelines for Exercise Testing and Prescription, 11th ed. (Table 4.7), from The Cooper Institute's Aerobics Center Longitudinal Study, more than 80,000 adults, maximal treadmill tests. Values in ml/kg/min.
What VO2 max is, in one paragraph
VO2 max is the maximum amount of oxygen your body can take in and use during all-out exercise, measured in millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). It reflects the size of your aerobic engine: how well your lungs, heart, blood, and muscles work together to deliver and burn oxygen when you push hard. A higher number means a bigger engine. It is one of the most studied numbers in exercise science and a strong marker of cardiorespiratory fitness, which is part of why so many watches now estimate it.
What the reference numbers actually show
The standard reference is the percentile data from the Cooper Institute's Aerobics Center Longitudinal Study, the same tables used in the ACSM exercise guidelines. They come from more than 80,000 adults who completed maximal treadmill tests with direct gas analysis, broken down by age and sex. One pattern dominates.
VO2 max falls about 10% per decade after age 30, driven by drops in maximum heart rate, the blood pumped per beat, and lean muscle. The median for men slides from about 48 in their 20s to 24 by their 70s, and for women from about 38 to 18.1 Regular aerobic training roughly halves that rate of decline in the reference literature.
The second thing the data makes clear is the size of the sex difference. Men test about 15 to 20% higher than women of the same age, largely from higher hemoglobin, a larger heart relative to body weight, and more lean mass. This is exactly why VO2 max is read against your own age and sex, never as one universal number. Here is the full reference set.
| Age | Women | Men | ||||
|---|---|---|---|---|---|---|
| Low (25th) | Median | High (90th) | Low (25th) | Median | High (90th) | |
| 20–29 | 30 | 38 | 51 | 40 | 48 | 62 |
| 30–39 | 25 | 30 | 41 | 36 | 42 | 57 |
| 40–49 | 22 | 27 | 38 | 32 | 38 | 52 |
| 50–59 | 20 | 23 | 32 | 27 | 33 | 46 |
| 60–69 | 17 | 20 | 27 | 24 | 28 | 40 |
| 70–79 | 16 | 18 | 23 | 20 | 24 | 37 |
VO2 max in ml/kg/min, shown as 25th percentile, median (50th), and 90th percentile. Source: ACSM Guidelines for Exercise Testing and Prescription, 11th ed. (Table 4.7), from The Cooper Institute Aerobics Center Longitudinal Study, maximal treadmill tests. The interactive tool above uses the full 5th-to-95th percentile breakpoints.
How to read your own score against it
Find your age row and your sex. The median is the midpoint for people like you, the point half score above and half below. The ACSM framework then groups percentiles into categories: below the 20th is Poor, 20th to 39th Fair, 40th to 59th Average, 60th to 79th Good, 80th to 94th Excellent, and 95th or above Superior. These describe where you sit, not what you should do. The same 40 ml/kg/min that is merely Average for a 25-year-old man is Good for a 50-year-old man, because it is always read within your own age and sex.
The context that matters most is your own trend. A single VO2 max number, especially one estimated by a watch, is a snapshot. What tells you something is the direction over months: a number climbing as you train, holding steady, or drifting down. Where you sit in the table tells you the starting line. Your own trend tells you which way you are moving.
The percentile tells you where you're standing. Your own trend over the months tells you which way you're walking. The second one is usually the more useful answer.
Kate Maren, Editor
Why men score higher: on average men carry more hemoglobin to ferry oxygen, a larger heart relative to body size, and more lean muscle to use it. That raises oxygen delivery and use, which is why the same VO2 max sits at a different percentile for a man and a woman of the same age.
How accurate is your watch's VO2 max?
This is the caveat that matters most for this number. The reference values above come from maximal lab tests where you exercise to exhaustion in a mask that measures the oxygen you actually use. Your Garmin, Apple Watch, or Coros does something very different: it estimates VO2 max from the relationship between your heart rate and your pace during ordinary runs and walks. For many people that estimate lands within a few ml/kg/min of a lab value, which is genuinely useful. But the estimate leans on accurate heart rate and pace data, so it drifts when your heart rate readings are noisy, when you mostly do non-running exercise, or when conditions like heat distort the relationship.
The practical upshot: your watch's VO2 max is a good tracker of your own trend and a rough placement on the percentile table, not a precise verdict. A two- or three-point wobble between weeks is usually estimation noise, not a real change in fitness. Read the direction over months, not the digits week to week.
What moves VO2 max
Beyond age and sex, the research points consistently to the same levers. Aerobic training, especially efforts that push close to your peak, is the strongest driver of improvement, with untrained people often gaining 15 to 20% over a structured program in the literature. Consistent endurance volume, losing excess body fat (since the number is scaled to body weight), and simply being less sedentary all tend to track with higher values. On the other side, detraining, illness, and the steady pressure of age move it down. Naming these is not a training plan. It is so that when your number changes, you have a realistic sense of why.
What the data doesn't capture
A percentile tells you where you rank among people your age and sex. It does not tell you your health is good or bad on its own, and a wearable estimate is not a diagnosis. VO2 max is strongly associated with health outcomes across large studies,2 but that is a population association, and your single estimated number is not a verdict on your future.
Two honest limits. First, the reference cohort skews toward people fit and motivated enough to complete a maximal treadmill test, so the general-population picture, especially at the low end, may differ somewhat. Second, the number your watch shows is an estimate of a lab measurement, so any single cross-comparison to these tables carries real uncertainty. What the evidence strongly supports is using the percentile for orientation and tracking your own trend over months. What it does not support is treating one estimated figure as a precise statement about your body.
If you came here asking whether your VO2 max is good, the most defensible reading is this: find your age and sex above, see which percentile band your number falls in, remember that your watch's figure is an estimate, and then watch where your own trend goes over the coming months. That is what the data can honestly tell you, and it is enough to stop guessing.
Common questions
What is a good VO2 max for my age?
It depends entirely on your age and sex. The median for men falls from about 48 ml/kg/min in their 20s to about 24 by their 70s, and for women from about 38 to 18. A score above the 60th percentile for your age and sex is rated Good, above the 80th Excellent. There is no single good number across ages.
How accurate is my watch's VO2 max?
A watch estimates VO2 max from your heart rate and pace, not a maximal lab test. For many people it lands within a few ml/kg/min of a lab value, but individual estimates can be off by more and drift with noisy data. Treat it as a trend tracker, not a precise measurement.
Why does VO2 max decline with age?
It falls roughly 10% per decade after about 30, driven by reductions in maximum heart rate, the blood pumped per beat, and lean muscle mass. Regular aerobic training reduces the decline to roughly 5% per decade in the reference literature, though it does not stop it.
Do men and women have different VO2 max?
Yes. Men test about 15 to 20% higher than women of the same age, largely from higher hemoglobin, larger heart size relative to body weight, and more lean mass. This is why VO2 max is always read against age and sex rather than as a single universal number.
References
- American College of Sports Medicine (2021). ACSM's Guidelines for Exercise Testing and Prescription, 11th ed. (Table 4.7).
- Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W (2018). Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. doi:10.1001/jamanetworkopen.2018.3605
How accurate your watch's VO2 max estimate is, and how to improve the number, are covered with their own sources in the linked articles above.