What Is VO2 Max and How Is It Measured?

VO2 max is the maximum rate at which your body can consume oxygen during intense exercise. It's considered the gold standard measure of cardiovascular fitness because it reflects the efficiency of your heart, lungs, blood, and muscles working together.

What the Number Means

VO2 max is expressed in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). A typical untrained adult male might have a VO2 max of 35–40; an untrained adult female, 27–32. Elite endurance athletes like cross-country skiers often exceed 80–90 mL/kg/min.

Average VO2 Max by Age (Men / Women)

• 20–29: 43–52 / 33–42 mL/kg/min
• 30–39: 41–48 / 31–38 mL/kg/min
• 40–49: 38–44 / 28–35 mL/kg/min
• 50–59: 35–40 / 25–31 mL/kg/min
• 60–69: 30–36 / 22–28 mL/kg/min

How to Estimate Your VO2 Max Without a Lab

The Cooper Test: run as far as you can in 12 minutes. VO2 max ≈ (distance in meters − 504.9) ÷ 44.73. Alternatively, many modern GPS watches (Garmin, Apple Watch, Polar) estimate VO2 max from heart rate data during outdoor runs.

How to Improve VO2 Max

High-intensity interval training (HIIT) is the most effective method. Research shows 3–4 sessions per week of interval work at 90–95% max heart rate produces significant VO2 max gains within 6–8 weeks. Longer, steady Zone 2 cardio builds the aerobic base that supports higher-intensity improvements.