VO2 max by age falls steadily for men. In the US FRIEND treadmill reference data, the median was 48.0 mL/kg/min for men in their 20s, 37.8 in their 40s and 28.2 in their 60s. A result above the median means you are fitter than half the men tested at your age, and the 75th percentile marks the top quarter.
Those figures come from the 2015 FRIEND standards, and a 2022 update put treadmill values slightly lower. This guide gives the full table for men, explains which numbers to trust, what the longevity research does and does not show, and how far to trust the estimate on your watch.
What is VO2 max?
VO2 max is the highest rate at which your body can take up and use oxygen during maximal exercise. It is expressed in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min), and it is how cardiorespiratory fitness is measured directly.
The direct measurement comes from a cardiopulmonary exercise test (CPX), in which you exercise to exhaustion on a treadmill or bike while your breathing gases are analyzed. The FRIEND registry paper notes that fitness is often estimated from treadmill speed and grade instead, and that estimated and measured values differ.
Clinicians also describe fitness in METs, or metabolic equivalents. One MET corresponds to 3.5 mL/kg/min of oxygen uptake, as a 2026 validation study restates.
VO2 max by age for men: the FRIEND percentile table
The table below shows treadmill VO2 max percentiles for men from the 2015 FRIEND paper. It is based on 4,611 tests in men without known cardiovascular disease at eight US laboratories. A percentile shows where a result sits: at the 25th percentile, three quarters of men tested scored higher. All values are in mL/kg/min.
| Age | 25th percentile | 50th percentile (median) | 75th percentile |
|---|---|---|---|
| 20 to 29 | 40.1 | 48.0 | 55.2 |
| 30 to 39 | 35.9 | 42.4 | 49.2 |
| 40 to 49 | 31.9 | 37.8 | 45.0 |
| 50 to 59 | 27.1 | 32.6 | 39.7 |
| 60 to 69 | 23.7 | 28.2 | 34.5 |
| 70 to 79 | 20.4 | 24.4 | 30.4 |
On these figures, an average VO2 max for a man in his 40s is 37.8 mL/kg/min, and 45.0 puts him in the top quarter for his decade. The 90th percentile for that decade was 52.1.
The FRIEND papers report percentiles rather than labels such as good or excellent. Percentiles describe how you compare with tested peers; they are a benchmark, not a diagnosis.
Which VO2 max reference numbers should you trust?
The 2015 table is a reasonable benchmark with three caveats. First, the 2022 FRIEND update analyzed 22,379 tests from 34 US laboratories, including 16,278 treadmill tests, in apparently healthy adults aged 20 to 89. Its treadmill standards were 1.5 to 4.6 mL/kg/min lower than the 2015 values, so the older table is slightly demanding.
Second, the mode of testing matters. A cycle ergometer is a stationary bike that sets and measures the workload. The 2022 paper found median values were higher on a treadmill than on a cycle ergometer, so a bike test should be compared with cycle standards.
Third, the reference population is American. The 2015 FRIEND authors found that Norwegian men and women had notably higher fitness than US adults in every age group, and concluded that normal values are region and country specific. If you live in the UK or Australia, read the table as a US benchmark rather than a national norm.
The 2015 authors also note that their cohort was not entirely healthy: some participants had diabetes, obesity or cardiovascular risk factors.
Does VO2 max decrease with age?
VO2 max does decrease with age. In the 2015 FRIEND data, men's values fell by 9.2% per decade across a 50-year age range. The 2022 update estimated an average decline of 13.5%, or 4.0 mL/kg/min, per decade on the treadmill across men and women.
These figures compare different people at different ages rather than following the same men over time. Your own trajectory depends on more than the calendar.
Responses to training also vary widely. A review of the HERITAGE Family Study and other trials found that VO2 max responses to standardized training programs ranged from almost no gain to a 100% increase in sedentary people.
Is VO2 max linked to longevity?
Higher VO2 max is strongly linked with longer life, but the evidence is observational. A 2022 meta-analysis of 37 cohort studies with 2,258,029 participants found that people in the top third of cardiorespiratory fitness had a relative risk of death of 0.55 compared with the bottom third.
A relative risk of 0.55 means 45% lower risk over the follow-up period. The same analysis found that each 1 MET higher fitness was associated with an 11% lower risk of death from any cause.
Observational studies show association, not proof that raising your own VO2 max will add years. Fitter people may differ in other ways that also affect health.
How accurate is your Apple Watch or Garmin VO2 max?
Watch VO2 max estimates can differ substantially from laboratory measurements, and the studies cited here do not establish how reliably a watch tracks one person's changes over time. A 2022 meta-analysis by the INTERLIVE network pooled 14 validation studies of consumer wearables.
Devices whose algorithms rely on resting data overestimated VO2 max by 2.17 mL/kg/min on average, with limits of agreement from -13.07 to 17.41. Limits of agreement are the range within which most individual differences between the device and the lab test fell. Devices using exercise data had almost no average bias, but limits from -9.92 to 9.74 mL/kg/min. The authors concluded that individual error remains large.
The 2026 study of Apple Watch Series 10 tested 35 young adults with a mean age of 22.7. The watch underestimated VO2 max by 6.25 mL/kg/min on average, with a mean absolute percentage error of 13.2%. It placed only 5 people (14%) in the correct FRIEND percentile band, and 51% were misclassified by two bands or more.
Garmin and other brands use their own algorithms, so check whether a published validation exists for your model and your kind of exercise.
How can men improve VO2 max?
Training studies show VO2 max can rise with regular aerobic exercise, by very different amounts between people. Healthdirect summarizes the Australian guidelines as 2 hours 30 minutes to 5 hours of moderate activity a week, or 1 hour 15 minutes to 2 hours 30 minutes of intense activity, and advises starting slowly and building intensity over time.
Expect a range of responses rather than a guaranteed number. If you also lift, protein intake for men who lift covers the nutrition side. Healthdirect also notes that a doctor may refer you to an exercise physiologist if you have a medical condition, injury or disability.
Practical checks for your VO2 max number
1. Note how the number was measured.
A lab CPX, a treadmill time estimate and a watch algorithm are different measurements. Write down which one produced your figure before comparing it with any table.
2. Compare with the right reference.
Match sex, age decade and test mode. A cycle result compared with treadmill standards will look worse than it is.
3. Read watch changes cautiously.
If you use a watch, keep to the same device, similar routes and similar conditions, and treat small changes cautiously. The validation studies compared watches with laboratory tests at one point in time; they did not establish how repeatable a watch's own readings are.
4. Check that a lab test was maximal.
FRIEND only included treadmill tests with a respiratory exchange ratio (RER) of 1.0 or higher. RER is the ratio of carbon dioxide breathed out to oxygen taken up, which labs use to judge whether an effort was maximal, so ask for it on your report.
5. Keep fitness alongside other markers.
Record blood pressure with a proper technique, using our guide to home blood pressure measurement, and track waist size too; see visceral fat in men. Note sleep around test days, and read how much deep sleep before trusting a sleep score.
When to see a doctor before chasing a higher VO2 max
Healthdirect advises speaking with your doctor before you start if you have a health condition or have not been active for a while. In the US that is usually your primary care physician; in the UK or Australia, your GP. Ask whether supervised exercise testing makes sense for you.
If you feel pain or tightness in your chest, shortness of breath or dizziness during exercise, stop and rest. Healthdirect warns that chest pain that is severe, gets worse or lasts longer than 10 minutes needs an ambulance: call 911 in the US, 999 in the UK or 000 in Australia.
Frequently asked questions
What is a good VO2 max for a 40 year old man?
In the 2015 FRIEND treadmill data, men aged 40 to 49 had a median VO2 max of 37.8 mL/kg/min. The 75th percentile was 45.0 and the 90th was 52.1. The 2022 update set treadmill standards 1.5 to 4.6 mL/kg/min lower, so these figures are slightly demanding.
Does VO2 max decrease with age?
Yes. In the 2015 FRIEND data, men's VO2 max fell by about 9.2% per decade, and the 2022 update estimated 13.5% per decade across men and women. These are comparisons between age groups, and individual responses to training vary from almost no gain to large improvements.
Is the VO2 max on Apple Watch accurate?
Not precisely. A 2026 study of Apple Watch Series 10 found it underestimated lab-measured VO2 max by 6.25 mL/kg/min on average and placed only 14% of participants in the correct FRIEND percentile band. No study cited here shows how reliably a watch tracks one person's changes, so treat its number as a rough estimate.
Does VO2 max predict longevity?
Higher fitness is strongly associated with lower death rates. A 2022 meta-analysis of 37 cohort studies found an 11% lower risk of death for each 1 MET higher fitness. These studies are observational, so they show association rather than proof that improving VO2 max extends life.
Is a VO2 max of 40 good for a man?
A VO2 max of 40 depends on age. In the 2015 FRIEND treadmill data it sits just below the 25th percentile for men in their 20s, below the median in their 30s, above the median in their 40s and above the 75th percentile in their 50s and 60s.
The short version
VO2 max by age declines on average, so compare your number with your own decade, sex and test type. The FRIEND treadmill table is a solid US benchmark, though the 2022 update runs slightly lower. Higher fitness is linked with longer life in observational research. Treat watch estimates as rough, and build aerobic training gradually.
This article is general education, not medical advice. It does not replace your own physician.
