If you could only measure one number about your body, it should be VO2max. Few markers predict longevity so strongly, and almost no others can be trained up so directly.
Reading time 8 min · Updated April 2026 · Aevia Insights
- VO2max is the strongest single measure of fitness, and one of the strongest predictors of longevity.
- The difference between low and high fitness can amount to several years of life.
- It can be trained at any age with the right combination of easy and hard training.
- One number is enough to steer by, and it responds within weeks to months.
What is VO2max?
VO2max is the maximum amount of oxygen your body can take up and use under hard physical effort, measured in ml of oxygen per kilo of body weight per minute. It's the best overall measure of your cardiorespiratory fitness.
In short: how big is your engine? The higher your VO2max, the more your body can perform, physically and mentally, without running dry.
What is a good number?
VO2max falls naturally with age, but the level varies enormously. As a rough guide for men in their 40s and 50s:
- Below ~30 ml/kg/min: low, markedly increased risk
- ~35–42 ml/kg/min: average
- ~45–52 ml/kg/min: good, well-trained
- Above ~55 ml/kg/min: excellent, athletic level
The numbers are typically a few units lower for women. What matters isn't the absolute number, but where you stand for your age, and which way it's moving.
Why is it linked to longevity?
Large cohort studies show a strong, dose-dependent relationship: the higher the fitness, the lower the mortality, with no clear ceiling on the benefit.
Going from "low" to merely "average" fitness is associated with a risk reduction comparable in magnitude to quitting smoking. Few interventions move so much.
How to train it up
The most effective recipe combines two types of training, and doesn't require hours every day:
- Zone 2 (easy endurance): 2–3 sessions a week where you can still talk. Builds the aerobic foundation.
- High-intensity intervals: e.g. 4×4 minutes hard with rests, once a week. This is where VO2max really moves.
- Strength training: twice a week protects muscle mass and supports the rest.
How quickly can you improve it?
Untrained people often see measurable progress within 8–12 weeks. Even small increases shift risk noticeably, and it's never too late to start, even in your 50s and 60s the number rises with training.
How Aevia measures it
In the Plus and Elite packages we measure your VO2max directly at a sports-physiology lab, not an estimate from a watch, and build a concrete training protocol around your number.
At follow-up you see in black and white whether the course is right.
Frequently asked questions
Can't I just use the number from my smartwatch?
A watch gives an estimate that can be several units off. For making decisions and tracking small changes, a lab measurement is far more precise.
Am I too old to improve my VO2max?
No. Research shows progress in all age groups. Your starting point and trajectory matter more than your age.
How often should I re-test?
Twice a year is plenty to track progress and adjust your training to the results.
Figures and ranges are indicative. Always begin new, hard training based on your own condition, and seek advice if in doubt.