VO2 max is the gold-standard measure of aerobic fitness. Here's what's good for your age and sex, and how to raise it.
VO2 max is the maximum amount of oxygen your body can use per minute during hard exercise, measured in millilitres per kilogram of body weight per minute (ml/kg/min). It's the best single lab marker of aerobic fitness, and higher values are consistently linked with better endurance and lower all-cause mortality.
VO2 max declines gradually with age and runs lower in women on average, so "good" is judged within your own age and sex group. The rough "good" thresholds below are representative — elite endurance athletes often exceed 60.
| Age | Good (men) | Good (women) |
|---|---|---|
| 20–29 | 44–51 | 38–44 |
| 30–39 | 42–48 | 35–41 |
| 40–49 | 40–46 | 33–39 |
| 50–59 | 36–43 | 30–36 |
| 60+ | 33–40 | 28–34 |
A true VO2 max needs a lab, but two field methods get close. The resting heart rate method uses the ratio of your max to resting heart rate — a lower resting pulse reflects a stronger heart. The Cooper 12-minute run test estimates it from how far you run in 12 minutes. Our VO2 max calculator supports both.
Aerobic training raises VO2 max, especially interval work near your maximum effort combined with a base of steady endurance miles. Many people see gains of 5–15% over a few months. Training by heart-rate zones helps you hit the right intensities.