What is VO2 Max?
VO2 max (maximal oxygen uptake) is the maximum rate at which your body can consume oxygen during intense exercise. It is the standard lab measure of cardiorespiratory fitness and aerobic endurance, expressed in millilitres of oxygen per kilogram of body weight per minute (mL/kg/min).
Elite endurance athletes like marathon runners and cross-country skiers can have VO2 max values above 80 mL/kg/min. In the HUNT Fitness Study, which measured 3,816 healthy Norwegian adults on a treadmill, men in their twenties averaged 54.4 and women 43.0, and the average fell by about 8% with each decade of age.
VO2 Max Reference by Age (mL/kg/min)
| Age | Men, mean ± SD | Women, mean ± SD |
|---|---|---|
| 20-29 | 54.4 ± 8.4 | 43 ± 7.7 |
| 30-39 | 49.1 ± 7.5 | 40 ± 6.8 |
| 40-49 | 47.2 ± 7.7 | 38.4 ± 6.9 |
| 50-59 | 42.6 ± 7.4 | 34.4 ± 5.7 |
| 60-69 | 39.2 ± 6.7 | 31.1 ± 5.1 |
| 70 and over | 35.3 ± 6.5 | 28.3 ± 5.2 |
Source: Loe and colleagues, PLoS ONE 2013, HUNT 3 Fitness Study. The participants were healthy volunteers without heart or lung disease, so they are fitter than the general population. Being at the 50th percentile here is a good result. Roughly two thirds of each group fall within one standard deviation of the mean.
The three test methods
1.5-mile run: VO2 max = 483 ÷ time (minutes) + 3.5
12-minute run: VO2 max = (distance in meters − 504.9) ÷ 44.73 (Cooper, 1968)
Heart rate: VO2 max = 15.3 × max HR ÷ resting HR (Uth et al., 2004)
Worked example. You run 1.5 miles in 11 minutes 30 seconds, which is 11.5 minutes. 483 ÷ 11.5 = 42.0, and 42.0 + 3.5 = 45.5 mL/kg/min. For the heart rate method: a 40-year-old with a resting heart rate of 60 has an estimated maximum of 208 − 0.7 × 40 = 180, so 15.3 × 180 ÷ 60 = 45.9.
The run tests need an all-out effort on a flat track and assume you pace well. The heart rate method needs no exercise but is the least precise, especially if your maximum heart rate is estimated rather than measured. Beta-blockers and other drugs that change heart rate make it invalid.
Fitness Age Explained
Fitness age is the age at which an average healthy person has your VO2 max. A 45-year-old with a VO2 max equivalent to an average 30-year-old has a fitness age of 30. Researchers at the Norwegian University of Science and Technology (NTNU) developed the idea from HUNT data. In a 24-year follow-up of about 37,000 HUNT participants, among those under 60 each 1 MET (3.5 mL/kg/min) of higher estimated fitness went with a 21% lower risk of death from cardiovascular disease.
The calculator interpolates between the HUNT age-group averages, so fitness ages below 25 or above 75 are shown as "under 25" or "over 75".
How to raise it, and when to be careful
VO2 max responds to regular aerobic training, especially sessions that include some hard intervals. Untrained people usually improve most. If you have heart disease, chest pain on exertion, high blood pressure or have been inactive for a long time, talk to a doctor before an all-out run test. Stop at once if you feel chest pain, dizziness or unusual breathlessness.