What Is VO2 Max?
Published 10/15/2025 · 2 min read · Sport calculators
VO2 max is the maximum amount of oxygen your body can use during intense exercise, measured in millilitres per kilogram of body weight per minute (ml/kg/min). It's a benchmark of aerobic fitness: a typical untrained adult sits around 30–40, while elite endurance athletes exceed 70. You raise it with regular aerobic training, especially intervals.
VO2 max is the most oxygen your body can use during hard exercise — a benchmark of aerobic fitness. Here's what it means, typical values, and how to raise it.
What it measures
Think of VO2 max as the size of your aerobic engine: the most oxygen your muscles can take in and burn per minute at full effort. Because it's given per kilogram of body weight, it fairly compares people of different sizes. The higher it is, the more energy you can produce aerobically before fatigue sets in — which is why it tracks so closely with endurance performance in running, cycling and swimming.
Typical values
As a rough guide, an untrained adult sits around 30–40 ml/kg/min, a regularly active person 40–50, and a well-trained amateur 50–60. Elite endurance athletes run past 70, and the highest ever recorded are in cross-country skiers near 90. Values are typically a little higher in men than women and decline gradually with age — but training slows that decline, so a fit 50-year-old can outscore a sedentary 25-year-old.
How it's estimated
The gold standard is a lab test: you exercise to exhaustion on a treadmill or bike while a mask measures the oxygen you breathe in and the carbon dioxide you breathe out. Outside a lab, it's estimated — from how fast you can run a set distance, from your heart-rate response to a submaximal effort, or by the algorithms in a running watch, which infer it from pace and heart rate. The estimates are approximate but track your trend well over time.
How to improve it
Two things move VO2 max: training and body weight. On the training side, a big base of easy aerobic work plus regular intervals near your maximum effort — think repeats of three to five minutes hard, with recovery — pushes it up the fastest. On the weight side, because it's measured per kilogram, losing excess fat can raise the number even if your absolute oxygen use is unchanged. Consistency over months matters far more than any single hard session.
Frequently asked questions
- What is a good VO2 max?
- It depends on age and sex, but around 40+ is solid for a recreational adult and 50+ is very fit.
- How do I increase my VO2 max?
- Regular aerobic training, especially interval sessions near your maximum effort.
- How is VO2 max measured?
- Precisely in a lab with a breathing mask; estimated by watches from pace and heart rate.
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