What is VO2 max and can I improve it?
By Mert Yerekapan · Updated
VO2 max is the maximum amount of oxygen your body can take in and use during hard exercise, measured in milliliters per kilogram of bodyweight per minute. It's one of the best single markers of cardio fitness, and yes, you can raise it. Many people get 10 to 20 percent higher in a few months of regular training.
What counts as a good number
It depends on age and sex, so check your own range rather than a single target. As a rough idea for adults:
- Below about 35: low for most adults
- Around 35 to 45: average to good
- Above 45 to 50: high
- 60 and up: trained endurance athletes
It falls gradually with age, about 5 to 10 percent a decade if you stay inactive, and training slows that down a lot. Higher VO2 max is linked to better long-term health, which is part of why people care.
How it's measured
The gold standard is a lab test with a mask while you run or ride to exhaustion. Most people use the estimate from a watch or an app. Those estimates are decent for tracking changes in your own numbers but can be off by several points, so I'd treat them as a trend and not a score.
How to raise it
Two things move it the most:
- Hard intervals. Efforts of 3 to 5 minutes at a very hard pace, with equal rest, done 1 to 2 times a week. A classic version is 4 x 4 minutes hard, with 3 minutes easy between.
- A lot of easy volume. Regular sessions at an easy pace build the base that the hard work sits on.
Combined with 3 to 4 total sessions a week, that's enough. Beginners improve fastest. Trained people see smaller gains, and part of your ceiling is genetic.
Both the hard intervals and the easy volume sync from Apple Health into League of Fitness, scored by heart rate zones, so a 4 x 4 session and a steady easy run each count toward your daily match.
What else matters
Sleep, body composition and altitude all play a part but you can't control all of them. Don't chase the number day by day. It moves slowly, and a lower reading after a poor night's sleep doesn't mean you lost fitness.
If you plan a series of very hard intervals and have heart disease or any warning signs like chest pain or fainting, check with a doctor first. Intervals are covered in HIIT vs steady-state cardio.