RunInsight

What is VO2 Max?

VO2 Max, or maximal oxygen uptake, is the maximum amount of oxygen your body can use during intense exercise. It is considered the gold standard for measuring cardiorespiratory capacity and aerobic endurance in an athlete.

It is usually expressed in ml/kg/min (milliliters of oxygen per kilogram of body weight per minute). The higher this value, the more "engine" you have available to fuel your muscles while running.

Why does it matter for runners?

Think of your body as a car: VO2 Max is the engine displacement. A runner with a high VO2 Max can transport and use more oxygen, producing more energy to sustain higher speeds for longer without going into oxygen debt.

Although genetics play an important role (about 50%), specific training can significantly improve this value, especially in beginners and intermediate athletes.

How is it measured officially?

The most accurate way to measure VO₂ max is the cardiopulmonary exercise test (CPET). This test is performed in a lab with a mask connected to a respiratory gas analyzer while the athlete runs on a treadmill or cycles on an ergometer with progressively increasing intensity.

How to improve VO2 Max

To raise your maximal oxygen uptake, you need to push the cardiovascular system near its limits. The most effective workouts are:

• Long intervals (800m – 1200m): Runs at an intensity close to 90–95% of maximum heart rate.
• Interval training: Alternating intense efforts and active recovery.
• HIIT: High-intensity sessions that challenge the heart.

Reference values

Note: Elite athletes such as Kilian Jornet or Olympic marathoners can exceed 85–90 ml/kg/min.