A parameter that was once primarily associated with elite athletes is now appearing more frequently in research on health and longevity. We are talking about VO₂max, or maximal oxygen uptake, the maximum amount of oxygen the body can use during intense exercise. Scientific analyses indicate that cardiorespiratory fitness may affect the risk of chronic disease and life expectancy. This parameter can be improved through appropriately designed training.
What is cardiorespiratory fitness and how is it measured?
Cardiorespiratory fitness is the body’s ability to take in and use oxygen during physical activity. It reflects how effectively several systems work together, primarily the heart, lungs, blood vessels, and muscles. The more efficiently these systems function, the better the body can handle physical exertion.
The parameter most commonly used to assess cardiorespiratory fitness is VO₂max, which is the maximum amount of oxygen the body can use during intense exercise. It is considered one of the most important indicators of physical fitness and, in recent years, has also become an important marker of health and longevity.
VO₂max can be assessed in several ways:
- Wearables, such as Garmin, Polar, and Apple Watch
Modern sports watches can estimate VO₂max based on heart rate, running pace, and physical activity data. The result is approximate, but it makes it possible to track changes in fitness over time. - Cooper test
This is a simple field test that involves running as far as possible within 12 minutes. The distance covered during that time is measured and used to estimate cardiorespiratory fitness and approximate VO₂max. - Heart rate based methods
Some tests use the relationship between heart rate and exercise intensity. This data is then used to estimate cardiorespiratory fitness, although the result is less accurate than a controlled exercise test. - Cardiopulmonary exercise testing
This is the most accurate method of measuring VO₂max. During the test, the composition of exhaled air is analyzed while the person exercises on a treadmill or stationary bike. This makes it possible to directly determine the body’s maximum oxygen uptake.
VO₂max as a predictor of life expectancy
In recent years, cardiorespiratory fitness has appeared more frequently in research on health and longevity. Scientists are examining whether VO₂max is associated with the risk of chronic disease and life expectancy.
Research conducted so far suggests that people with higher cardiorespiratory fitness are less likely to develop cardiovascular disease and metabolic disorders such as type 2 diabetes. Cardiorespiratory fitness is therefore considered an important indicator of overall physical health.
Importantly, the health benefits are gradual. Every improvement in fitness reduces the risk of disease and death.
According to an Elevate Speaker
Why is VO₂max a good indicator of longevity?
“One study followed a large group of middle aged men for 40 years after their VO₂max had been measured. The findings were very clear. People with the highest fitness levels had a five or six times lower risk of death than those with the lowest VO₂max. This applied not only to cardiovascular disease, but also to deaths from other causes, including cancer.rnWe therefore know that people with the highest fitness levels live longer on average. However, this does not mean that everyone needs to reach the level of elite athletes. Simply moving from the lowest fitness category to an average level significantly improves the outlook and may reduce the risk of death by two or even three times.rnVO₂max is such a strong health indicator because it reflects the function of several systems at the same time: the heart, lungs, blood vessels, and muscles. It shows how much oxygen the body can take in and use during maximum exertion, and in practice, this tells us a great deal about overall physical condition.”
VO₂max reference ranges by age and sex
Today, VO₂max can be estimated relatively easily, for example through a field test or with a sports watch. But how should the result be interpreted?
The number itself says very little unless it is considered in relation to age, sex, and activity level. The same result may indicate excellent fitness in one person and average fitness in another.
Differences in VO₂max values are largely natural. Higher values are more commonly recorded in men than in women, partly because of greater muscle mass and higher hemoglobin levels. Lifestyle also plays an important role. As might be expected, people who exercise regularly achieve better cardiorespiratory fitness than those who lead a sedentary lifestyle.
VO₂max also changes with age. Over time, physical fitness gradually declines, on average by approximately 1% per year, or about 10% per decade. However, the rate of decline is not the same for everyone. Research shows that inactive people may lose cardiorespiratory fitness up to twice as quickly as those who exercise regularly.
The tables below present approximate VO₂max values for different age groups and sexes. They allow you to compare your result with the general population.
How to improve VO₂max: 4 methods that really work
Research identifies four approaches with proven effectiveness. They differ in intensity, duration, and the demands they place on the body. This protocol is used by Elevate founder Michał Wieczorek, among others. It has helped him maintain a VO₂max of 60 ml/kg/min.
1. Continuous endurance training
Who it is for: people who are just starting to exercise
Effect: studies show an average VO₂max increase of +4.9 ml/kg/min
This is a long period of steady, low intensity exercise performed in heart rate zone 2, which corresponds to 60 to 70% of HRmax.
- Running, cycling, swimming, or Nordic walking
- Duration: at least 45 minutes, ideally 60 to 90 minutes
- Intensity: you should be able to speak comfortably and breathe through your nose throughout the workout
- Heart rate: 60 to 70% of HRmax, which for a person with an HRmax of 180 is approximately 108 to 126 beats per minute
- Maintain a steady intensity throughout
Talk test: if you can say a full sentence without becoming breathless, but cannot sing, you are in zone 2.
2. REHIT: maximum effect in minimum time
Who it is for: people with limited time who want to add a stronger stimulus to their aerobic training
Effect: studies show a +12% increase in VO₂max within 8 weeks
This is probably the most time efficient method of improving cardiorespiratory fitness. The entire session takes approximately 10 minutes.
Protocol step by step:
| Phase | Duration | Intensity |
| Warmup | 3 min | RPE 2 to 3, very easy |
| Sprint 1 | 20 seconds | RPE 9 to 10, absolute maximum |
| Active recovery | 3 min | RPE 2 to 3, very easy |
| Sprint 2 | 20 seconds | RPE 9 to 10, absolute maximum |
| Cooldown | 3 to 4 min | RPE 2, very easy |
RPE, or Rating of Perceived Exertion, is a subjective scale of effort from 1 to 10. RPE 9 to 10 literally means “I cannot do any more,” which corresponds to sprinting at 100% of your capacity.
Key principles:
- It is best performed on a stationary bike or ergometer because the intensity is easy to control and there is less risk of injury during sprinting
- It can be performed after zone 2 training, but never before it, because muscles fatigued by sprinting do not train aerobically as effectively
- Progression: begin with 2 sprints of 20 seconds each, then add a third sprint after a few weeks
3. The 4×4 interval: the Norwegian method
Who it is for: people who have already built several weeks of aerobic fitness
Effect: studies show a +7.2% increase in VO₂max within 8 weeks
This protocol was developed in Norwegian sports laboratories and is one of the most extensively studied methods of improving VO₂max. The key is working at approximately 90 to 95% of HRmax for a total of around 16 minutes. This is long enough to stimulate cardiovascular adaptations.
Protocol step by step:
| Phase | Duration | Intensity |
| Warmup | 10 min | Easy, gradually increasing |
| Interval 1: work | 4 min | 90 to 95% HRmax |
| Interval 1: recovery | 4 min | Approximately 70% HRmax, active recovery |
| Interval 2: work | 4 min | 90 to 95% HRmax |
| Interval 2: recovery | 4 min | Approximately 70% HRmax |
| Interval 3: work | 4 min | 90 to 95% HRmax |
| Interval 3: recovery | 4 min | Approximately 70% HRmax |
| Interval 4: work | 4 min | 90 to 95% HRmax |
| Cooldown | 10 min | Easy |
Total workout duration: approximately 50 minutes. Of this, 16 minutes are performed at a very high heart rate.
How to control intensity:
- Use a sports watch with heart rate monitoring. Your heart rate will rise during the first minute and should reach 90 to 95% of HRmax around the second or third minute, then remain there
- Set your running or cycling pace so that by the third minute of the interval, you feel as though you are close to your limit
- Active recovery does not mean sitting still. It should involve light jogging or easy cycling that allows your heart rate to fall to approximately 70% of HRmax
4. HIIT: high intensity intervals
Who it is for: advanced exercisers, as a complement to an aerobic base
Effect: studies show an increase in VO₂max of +5.5 ml/kg/min
HIIT, or High Intensity Interval Training, is a broad category of workouts in which short periods of high intensity effort alternate with recovery periods. The Tabata protocol, consisting of 8 rounds of 20 seconds of work followed by 10 seconds of rest, is one of the most popular examples.
For improving VO₂max, HIIT works in a similar way to 4×4 intervals, but uses shorter work periods. It is a good option for people who enjoy variety or do not have 50 minutes for a full Norwegian style session.
The most common mistake: the gray zone
The biggest mistake people make when trying to improve VO₂max is training continuously in the middle, neither easy enough nor hard enough. These sessions do not build an aerobic base because they are too intense for zone 2, and they do not stimulate the necessary adaptations because they are too easy to qualify as true HIIT. The result is substantial fatigue with little progress.
Polarized training means that most sessions are performed at a very easy intensity in zone 2, while short portions are completed at a very high intensity.
When you include REHIT or 4×4 intervals, these should represent moments of maximum intensity. When you train in zone 2, the effort should be easy enough that you do not feel tired after an hour.
Can cardiorespiratory fitness be improved after age 40?
Although VO₂max declines with age, this does not mean that fitness is fixed. In many cases, people who begin exercising after age 40 can increase their VO₂max by more than 10%.
Experts emphasize that the potential for improving VO₂max varies from person to person.
“On average, VO₂max can be improved by approximately 20% through training. However, this depends largely on genetic predisposition. Each of us has a natural level that cannot be increased indefinitely. The most important thing is to gradually improve your fitness and then maintain it through regular physical activity. A model in which approximately 80% of training is performed at moderate intensity and around 20% at higher intensity works well. Pushing the body excessively rarely provides additional benefits and may increase the risk of injury, overtraining, or chronic fatigue.”
Conclusions
VO₂max reveals a great deal about the body’s overall condition and may affect the risk of chronic disease and life expectancy. The good news is that cardiorespiratory fitness can be improved through regular physical activity, even in middle age. Measuring your VO₂max and working to improve it may therefore be one of the simplest steps toward a longer and healthier life.
