Aerobic capacity from distance run in 12 minutes.
Source: Cooper, JAMA 1968.
What does VO₂max mean?
VO₂max (maximal oxygen uptake) is the maximum rate at which the body can consume oxygen during intense exercise, expressed in millilitres of O₂ per kilogram of body weight per minute (mL/kg/min). It is the single best indicator of cardiorespiratory fitness and aerobic endurance capacity, and is strongly associated with cardiovascular health, longevity, and athletic performance.
The Cooper 12-minute run test was developed by Dr Kenneth H. Cooper, published in JAMA in 1968. Cooper established that the distance covered in 12 minutes correlates well with laboratory-measured VO₂max. The formula is: VO₂max = (distance in metres − 504.9) ÷ 44.73. It was originally developed for US military fitness assessment and has since been validated in diverse populations.
VO₂max declines naturally with age, approximately 1% per year after age 25 in sedentary individuals, and more slowly in active people. A major long-term study from the Norwegian School of Sport Sciences found that every 3.5 mL/kg/min increase in VO₂max was associated with approximately 10–15% lower risk of all-cause mortality. Low VO₂max is now considered a stronger predictor of cardiovascular mortality than smoking, hypertension, or diabetes by some analyses.
The Cooper test is a maximal effort test, you must run as hard as you can for the full 12 minutes for an accurate result. It is not appropriate for untrained individuals, those with known cardiac conditions, or anyone who is unwell.
Reference ranges (men, age 20–29)
| Category | Men (mL/kg/min) | Women (mL/kg/min) |
|---|---|---|
| Very poor | < 33 | < 25 |
| Poor | 33 – 36 | 25 – 31 |
| Fair | 37 – 41 | 32 – 36 |
| Good | 42 – 52 | 37 – 45 |
| Excellent | 53 – 60 | 46 – 54 |
| Superior | > 60 | > 54 |
When should you see a doctor?
Before performing the Cooper test, adults over 40 or anyone with cardiovascular risk factors should have medical clearance. A very low VO₂max (below 18 mL/kg/min) in younger adults may indicate underlying cardiopulmonary disease and should prompt medical evaluation. Symptoms during the test, chest pain, severe breathlessness, or dizziness, require stopping immediately and seeking medical attention.
Frequently asked questions
What is a good VO₂max?
VO₂max norms vary by age and sex. For men aged 20–29, 42–46 mL/kg/min is average and above 52 is excellent. For women aged 20–29, 36–40 mL/kg/min is average and above 45 is excellent. Elite endurance athletes may achieve VO₂max values of 70–90 mL/kg/min. VO₂max naturally declines with age at about 1% per year after age 25 without training.
How do I perform the Cooper 12-minute run test?
Run (or walk/run) as far as possible in exactly 12 minutes on a flat surface, a running track is ideal for accurate distance measurement. Warm up for 5–10 minutes first. Maintain the highest sustainable pace throughout. After exactly 12 minutes, record the total distance covered. Enter this distance into the calculator.
Can VO₂max be improved?
Yes. VO₂max is trainable, structured aerobic training can improve it by 15–20% over several months in untrained individuals, and modest improvements are possible even in well-trained athletes. High-intensity interval training (HIIT) is particularly effective for increasing VO₂max. However, there is a strong genetic component, some people respond more to training than others.