VO₂max: the number that predicts how long you live.
VO₂max is the maximum rate at which your body can take in and use oxygen during exercise. It is the single strongest predictor of all-cause mortality — a higher number means a lower risk of dying, with a larger effect than smoking status, blood pressure, or diabetes. Here is what it is, what a good score looks like, and the fastest way to raise it.
What is VO₂max?
VO₂max — “V” for volume, “O₂” for oxygen, “max” for maximum — is the ceiling on how much oxygen your body can deliver to and use in your muscles per minute. It is measured in millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). The higher it is, the more aerobic work you can sustain.
It reflects the whole oxygen-delivery chain: how much blood your heart pumps, how well your blood carries oxygen, and how effectively your muscles extract it. That is why it is such a broad barometer of cardiovascular health, not just athletic performance.
Why VO₂max predicts how long you live
In a study of more than 120,000 people, higher cardiorespiratory fitness was associated with progressively lower mortality — and there was no upper limit: the fittest group lived longest, and being unfit carried a risk comparable to or greater than smoking, diabetes, or heart disease (Mandsager et al., JAMA Network Open, 2018).
A large meta-analysis put a number on it: each 1-MET higher fitness (about 3.5 ml/kg/min) was linked to roughly a 13% lower risk of all-cause mortality (Kodama et al., JAMA, 2009). Few modifiable factors move the longevity needle as much — and VO₂max is highly trainable.
What is a good VO₂max by age?
VO₂max declines with age and differs between sexes, so “good” is relative. The table below shows approximate average values; being comfortably above the average for your age group is a solid target, and elite endurance athletes reach 60–85 ml/kg/min.
| Age | Men (ml/kg/min) | Women (ml/kg/min) |
|---|---|---|
| 20–29 | 48 | 42 |
| 30–39 | 44 | 38 |
| 40–49 | 40 | 35 |
| 50–59 | 36 | 32 |
| 60–69 | 32 | 28 |
| 70+ | 28 | 25 |
Approximate population averages for reference; norms vary by dataset and testing method. Treat them as a guide, not a pass/fail line — your own trend over time matters more than any single number.
How to raise your VO₂max
The fastest, best-evidenced way is high-intensity intervals that put you at or near VO₂max for several minutes at a time. The Norwegian 4×4 — four four-minute intervals above 85% of max heart rate — is the most-studied protocol, raising VO₂max by about 7% in eight weeks in the original trial.
- Do intervals 2–3× per week. The 4×4 is the workhorse; that is where the VO₂max gains come from.
- Build an easy aerobic base with longer, low-intensity sessions on other days — it raises the ceiling your intervals push against.
- Be consistent and progressive. Measurable gains show up in 6–8 weeks of regular training; the number keeps moving for months.
The catch is dose: an interval only builds VO₂max if you actually spend the time near it. That is why a threshold-gated timer — one that only counts time above 85% of max heart rate — makes the gains repeatable and trackable.
How VO₂max is measured
There are three common ways, from most to least precise:
- Lab test (CPET). A graded test to exhaustion wearing a mask that measures the oxygen and carbon dioxide in your breath. The gold standard.
- Wearable estimate. Garmin and Apple Watch estimate VO₂max from your heart rate relative to pace or power. Convenient and good for tracking trends, though less accurate in absolute terms.
- Field test. Submaximal or all-out efforts like the Cooper 12-minute run plug into formulas that estimate VO₂max. Free, rough, and repeatable.
Frequently asked questions
- What is a good VO₂max?
It depends on age and sex. As a rough guide, an average 30–39-year-old man is around 44 ml/kg/min and an average woman around 38; anything comfortably above the average for your age group is good, and elite endurance athletes reach 60–85. What matters most for health is being above average for your age — and improving over time.
- What is VO₂max measured in?
Millilitres of oxygen used per kilogram of body weight per minute (ml/kg/min). One MET — a common fitness unit — equals 3.5 ml/kg/min.
- How can I increase my VO₂max?
The most time-efficient way is high-intensity intervals near VO₂max, with the Norwegian 4×4 having the strongest evidence base, built on a foundation of regular easy aerobic training. Consistency over 6–8 weeks is what moves the number.
- Can you improve VO₂max after 50?
Yes. VO₂max declines with age on average, but training raises it at any age — the same interval protocols that work for younger people work for older adults, and the relative gains are similar. Raising it partly offsets the age-related decline.
- How is VO₂max measured?
The gold standard is a graded exercise test (CPET) in a lab with a mask measuring oxygen and CO₂. Outside a lab, smartwatches estimate it from heart-rate and pace data, and field tests like the Cooper 12-minute run give an approximation.
- Does VO₂max really predict how long you live?
Large cohort studies find cardiorespiratory fitness is one of the strongest predictors of all-cause mortality — a stronger signal than smoking, high blood pressure, or diabetes — with no observed upper limit to the benefit of being fitter.
Train at VO₂max.
The Norwegian 4×4 is the most efficient way to raise VO₂max. Stellar Intervals runs it the way it was studied — the timer only counts above 85% of max heart rate.