
Read time: 5min.
By Coach Yan Busset
Some argue that VO2 max is largely dictated by genetics, with 40-60% of its potential predetermined at birth. Sorry for those of you who were about to give up because they thought mother nature was not generous enough with them, this only partially true, the remaining 40-60% offers significant room for improvement through smart training, making VO2 max both a fixed trait and a highly trainable one. As a coach, it's really important for me that my athletes understand the logic behind their training. My blog is one of the ways I aim to achieve that. Sharing as much as possible helps my athletes not only execute their sessions better but also engage with the process more fully. When they understand what's behind the training, it´s more fun, so you are far more likely to stay consistent, and consistency is the key to success.
Today, let´s dive deep into VO2 max: what it means, its importance in training, and how to develop it effectively.
What is VO2Max?
VO2max, or maximal oxygen uptake, is the maximum volume of oxygen your body can use during intense exercise. It is scientifically measured in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min). This metric reflects how efficiently your body delivers oxygen to your muscles and how effectively your muscles use that oxygen to produce energy.
From a scientific perspective, VO2max is the product of two key components:
Cardiac Output: The amount of blood your heart pumps per minute, which depends on heart rate and stroke volume (the volume of blood pumped with each beat).
Arterial-Venous Oxygen Difference: How much oxygen your muscles extract from the blood as it flows through them.
To put it more simply, VO2max is a measure of how big and powerful your engine is. The bigger your engine, the more energy you can produce to keep going. The higher your VO2max, the more oxygen your body can use to fuel your effort, which is a key advantage in endurance sports.
Let’s use a car analogy: VO2max is like the size of the engine—a bigger engine has more power. Meanwhile, your fundamental endurance is like fuel efficiency, it determines how far you can go on a single tank of fuel. Both are important, but VO2max sets the limit on how much power you can generate.
Why is it Important to Develop VO2Max?
For endurance athletes, training at lower intensities and building a strong zone 2 foundation is often the priority. However, including VO2max training is just as essential, even if it seems less obvious. VO2max improvements bring about both central and peripheral adaptations, which are key to overall endurance performance.
Central Adaptations: These occur in the cardiovascular system, including an increase in heart stroke volume and enhanced cardiac output, allowing more oxygen-rich blood to be delivered to working muscles.
Peripheral Adaptations: These take place in the muscles themselves, such as improved capillary density and mitochondrial function, enabling muscles to extract and use oxygen more efficiently. A higher VO2max not only makes you a better endurance athlete, but it also supports many other aspects of your performance. Here’s why:
Increased Aerobic Power: VO2max directly influences how much energy you can produce using oxygen. The higher your VO2max, the harder you can work for longer periods.
Boosted Fat Max: Fat max refers to the intensity at which your body uses the highest percentage of fat as fuel. While VO2max training supports overall metabolic flexibility, longer-duration VO2max intervals in particular can play a role in enhancing your ability to utilize fat as an energy source. However, zone 2 training remains the primary driver for maximizing fat-burning efficiency.
Improved Mitochondrial Function and Blood Flow: Training at high intensities enhances the efficiency and functionality of your mitochondria (your body’s energy factories) and improves blood flow to your muscles. These adaptations are essential for sustaining effort over time.
Zone 2 training builds your foundation, but VO2max training is what raises the ceiling. Together, they make you a more complete athlete, capable of sustaining higher levels of performance.
How to Improve VO2Max
Improving VO2max is a process that takes time. While genetics play a role in setting your baseline, consistent and structured training can lead to significant improvements. VO2max also tends to decline with age, so including it in your training helps maintain your fitness over the years.
A key to success is balancing high-intensity work with proper recovery. If you push too hard during low-intensity sessions, you won’t have enough energy to perform well in your VO2max workouts. This is why a polarized approach (80% of training at low intensity and 20% at high intensity) is so effective.
Here are some strategies to built a VO2 max session:
We all know the classics 30s/30s or 1min/1min classics. They are good once especially when you get started with interval trainings, but quickly you will need to increase the effort duration in order to make more progresses.
Session Duration:
VO2max workouts usually involve 15-30 minutes of total hard effort, split into intervals.
Each interval should last 2-6 minutes, which is the optimal range to stimulate VO2max.
Recovery:
A common rule is to match recovery time to work time (e.g., 3 minutes of effort, 3 minutes of recovery).
For advanced athletes, reducing recovery time can make sessions more intense and challenging.
Sustained Intervals:
Efforts of 3-5 minutes at 90-100% of your VO2max pace push your body to its limits and create long-lasting adaptations.
Take away session:
Decreasing Intervals, This format keeps things engaging while ensuring high-quality work throughout the session. Its a good session if you are already doing regular VO2Max sessions and you want to try something different to push through a plateau.
after a 10-20min warm up perfom a main set of:Â
 2x4min effort / 4min recovery+ 4x2min effort / 2min recovery + 4x 1min effort / 1min recovery

Effort Guidelines:
When doing VO2max intervals, aim for your best sustained effort for each interval. On the bike, this might be 105-120% of your Functional Threshold Power (FTP). However, it’s more about how it feels: push hard but stay controlled. Going all-out in the last few intervals might feel satisfying in the moment, but it often leads to longer recovery times without much added benefit. Keeping a consistent, strong effort across all intervals is the smarter choice for long-term progress.
VO2Max Kinetics and High-Intensity Interval Training (HIIT)
VO2max kinetics refers to how quickly your body can reach its maximum oxygen uptake. Improving this means you can adapt faster to high-intensity efforts, which is useful in both racing and training. One effective method for enhancing VO2 max kinetics is High-Intensity Interval Training (HIIT).
Example HIIT Session:
10x40 seconds at VO2max pace with 20 seconds recovery.
Rest for 4 minutes.
Repeat the set for a total of 20 intervals.
These short bursts of high intensity, combined with minimal recovery, force your body to adapt to rapid oxygen demands, improving both your VO2max and your ability to handle dynamic efforts.
VO2Max Beyond Performance
VO2max isn’t just about winning races, it’s also a key marker of overall health. Research, like the study Survival of the Fittest: VO2 Max as a Key Predictor of Longevity by Strasser and Burtscher, shows that higher cardiorespiratory fitness is linked to lower risks of all-cause and disease-specific mortality. Regular high-intensity interval training, combined with steady zone 2 work, not only enhances performance but also supports long-term health and quality of life.
The study emphasizes that while exercise might not extend your absolute lifespan, it significantly improves functional capacity—helping you stay active, independent, and healthy as you age. In short, training your VO2max isn’t just about your next race; it’s about thriving for years to come.
So now I hope that next time your coach gives you VO2Max sessions you will know what is the logic behind. And regardless how genetically gifted we are we can still improve it and we are doomed to take care of it because whether you’re striving for a personal best or aiming to stay fit and healthy, training your VO2max unlocks better endurance, resilience, and even a longer, more active life.
Yes, these sessions can leave you gasping for air, but think of it as your body’s way of saying, "Thank you for upgrading me!" So, keep the effort controlled, enjoy the process, and remember: you’re not just building a better engine; you’re investing in a better, healthier you.
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