VO₂max is the maximum amount of oxygen the body can take up and use at peak effort. It is the key measure of aerobic endurance and of how well the "lungs → heart → muscles" system works.
Of all fitness tests, VO₂max is one of the strongest predictors of lifespan: poor aerobic fitness is more dangerous than smoking or diabetes, and every extra point meaningfully lowers mortality. It is closely tied to resting heart rate and muscle mass.
Reference ranges
VO₂max (mL/kg/min) depends strongly on age, sex and fitness:
| Men 20–29 years (average) | ≈ 45 – 55 |
| Women 20–29 years (average) | ≈ 35 – 43 |
| Decline with age | ≈ 10% per decade |
| Endurance athletes | 60 – 90+ |
| Poor fitness (risk) | < 18 – 20 |
What an elevated level means
A high VO₂max is a sign of excellent cardiovascular fitness and longevity. Such people tolerate exertion more easily and have a lower risk of heart attack, diabetes and death from any cause.
The good news: VO₂max is trainable at any age. The most effective approach combines aerobic exercise with high-intensity interval training (HIIT).
What a low level means
A low VO₂max is an independent risk factor for early death, comparable in importance to smoking. It means the heart, lungs and muscles supply the body with oxygen poorly.
Causes: physical inactivity (the main one), age, excess weight, heart and lung disease, anemia. Even a small increase in VO₂max through regular exercise noticeably improves the outlook.
How the test is done
The gold standard is a cardiopulmonary exercise test (on a treadmill or cycle ergometer with gas analysis). In everyday life VO₂max is estimated by fitness watches (from heart rate and pace) and field tests (for example, the Cooper test).
Gadget estimates are approximate but reflect the trend well — and it is the trend you should focus on when training.
What affects the value
- Regular aerobic and interval training — raises VO₂max.
- Physical inactivity — the main cause of low values.
- Age — lowers VO₂max by about 10% per decade.
- Excess weight — lowers the value (per kg of mass).
- Anemia and heart/lung disease — lower it.
- Altitude and acclimatization — affect the result.
Estimate your fitness age
VO₂max is the basis of fitness age; assess your aerobic fitness:
Frequently asked questions
Why is VO₂max called the best longevity marker?
Large studies have shown that poor aerobic fitness carries a higher risk of death than smoking, diabetes or hypertension. VO₂max reflects the whole oxygen-delivery system, so it predicts both the length and the quality of life well.
How do you raise VO₂max?
The most effective approach combines regular aerobic exercise (running, cycling, swimming) with high-intensity interval training (HIIT). VO₂max improves at any age, and even a small gain noticeably lowers risk.
Can you trust the VO₂max from a watch?
A fitness watch's estimate is approximate and usually less accurate than a lab test, but it tracks the trend well. Focus on the direction (whether the value is rising) rather than the exact number.
Related terms
Sources
- Reference Standards for Cardiorespiratory Fitness (CPET) — NCBI/PMC
- Cardiorespiratory fitness and longevity (review). NCBI/PMC
- Aerobic capacity reference data, 20–90 y. PubMed