Key facts
- Measured in millilitres of oxygen per kg per minute.
- A strong marker of aerobic fitness and health.
- Improved by both endurance and interval training.
- Declines with age but trainable at any age.
VO2 max represents the ceiling of your aerobic engine — how much oxygen your heart, lungs, and muscles can take in and use when you're working as hard as you can. A higher VO2 max means a more capable cardiovascular system and better endurance, and it's one of the strongest predictors of long-term health.
You can raise it with training, particularly a mix of higher-intensity intervals (which push the ceiling) and lots of easier aerobic work (which builds the base). While genetics set part of your potential, consistent cardio improves VO2 max at any age, even as it naturally declines over time.
Frequently asked questions
How do I improve my VO2 max?
Combine high-intensity interval training, which directly challenges your aerobic ceiling, with a base of easier steady-state or Zone 2 cardio. Consistency over months drives the gains.
Is VO2 max a good measure of fitness?
Yes — it's one of the best single markers of cardiovascular fitness and is strongly associated with endurance performance and long-term health.
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