What is VO2 Max?

VO2 max is a universal indicator of physical performance. It determines the maximum amount of oxygen the body can consume during intense exercise. A high level of VO2 max can be created through training, but its level is largely determined by genetic predisposition.

VO2 max determines the body’s aerobic capacity for performing exercise. The higher it is, the longer and more intensely you can train and achieve better performance. A low VO2 max indicates that you are physically unable to withstand high training loads.

What Factors Influence VO2 Max Levels

Several factors affect VO2 max in different people:

1. Gender

Due to lower body weight and less muscle tissue, women achieve lower VO2 max values than men.

2. Age

VO2 max increases from childhood and peaks during adolescence. After this, the value decreases slightly and remains constant until 30 years. It then decreases systematically from year to year—in 40-year-olds, it reaches approximately 90% of the maximum value, in 50-year-olds, it reaches less than 80%, and in individuals 60 years old and older, it decreases to 60% of the initial value.

3. Exercise

Regular exercise increases lung capacity and heart stroke volume and decreases resting heart rate, resulting in higher oxygen consumption and more efficient oxygen utilization in energy production processes.

4. Genetics

The maximum VO2 max achieved through training depends on how the muscles are built. This, in turn, is inherited from ancestors. For example, some people have muscle fibers that contract faster (better suited for anaerobic exercise). 

This means that endurance sports, such as long-distance running or cycling, will not perform as well as people with a predominance of slow fiber contractions (better adapted to aerobic exercise). Similarly, VO2 max is influenced by the genetically determined number of capillaries, their diameter and the amount of blood that can flow through them.

V02 Max and Health

VO2 max, understood as the ability to produce energy from oxygen, shows us a person’s functional capacity. From a cardiovascular perspective, the higher your VO2 max, the lower your risk of death from cardiometabolic disease, and the better your physical performance.
If we don’t exercise, our VO2 max will decrease yearly, which will only worsen the quality of our health.

How much does VO2 max decrease throughout a lifetime? Studies have shown that the average rate of decline starting at age 30 has been 13.5% per decade, meaning that the average person’s VO2 Max decreases by ~4.0 ml/kg/min every 10 years.

How to Increase VO2 Max

If VO2Max is about utilizing oxygen in the muscles to produce energy, how can we improve it? First of all, it’s important to understand the basics. We need a good respiratory system to get oxygen from the air to the muscle cells. This system takes oxygen from the air and transports it into the bloodstream. 

Once the oxygen enters the bloodstream, the cardiovascular system must transport the oxygen to the working muscles. Red blood cells with oxygen carriers (hemoglobin) must start moving. This is the work of your heart, using its stroke volume and (maximum) heart rate.

Finally, when the oxygen reaches the muscle, it must diffuse (penetrate) into the muscle to enter the mitochondria, which will eventually use the oxygen to produce energy.

High aerobic energy production (VO2Max) in muscle requires good oxygen transport of all these systems. Theoretically, there could be many weak links that would increase VO2Max with improvement. Through training and nutrition, you could aim to, for example:

• Increase blood volume, red blood cells, stroke volume, and maximal heart rate;
• Increase muscle oxygen diffusion;
• Increase the quantity and quality of mitochondria.

In practice, however, the limiting factor often occurs within the muscle. Even during intense exercise, the blood that returns from the muscle to the lungs contains significant oxygen. Only when there is a sudden change in oxygen demand (power output) can the oxygen supply be the limiting factor for a few seconds.

When training, standard VO2Max improvement practices should focus on improving the muscle’s ability to utilize oxygen for energy production. Generally, every workout that increases oxygen consumption will stimulate your body to increase VO2 max. 

For example, long, slow endurance workouts or high-intensity interval training (HIIT). Therefore, it is important to do regular exercise when you want to increase your VO2 max.
Some people think that VO2Max is predetermined by genetics. Indeed, some aspects are at least partially genetically determined, such as:

• How quickly your VO2Max adapt to training
• How high your VO2Max can become
• How much you need to do in a workout to increase your VO2 max

However, VO2 max is also easily trainable. It is one of the metrics that can be trained in endurance sports. VO2 max increases with good training and decreases with inactivity (or training too hard).

Any workout that uses oxygen will increase your VO2 max. The more you use oxygen, the more you affect your VO2 max. However, you must realize that only a comprehensive approach in different intensity zones can positively influence this index.

Here are a few examples of high-intensity training aimed at increasing VO2Max:

Example 1:

Warm-up: 15 minutes in zone 0-1. 3 times 10 seconds fast for 3 minutes in zone 1. Rest for 1 minute.

Work: 5 minutes in zone 2, 2 minutes in the beginning-middle of zone 3, then 3-4 minutes in zone 4. So repeat 4 times, rest between intervals 2 minutes, step 2 minutes in zone 1.

Warm-up: 10 minutes in zone 0.

Example 2:

Warm-up: 15 minutes in zone 0-1. 3 times 10 seconds fast in 3 minutes in zone 1. Rest for 1 minute.

Work: 2 minutes in zone 3 + 4 minutes in zone 4. So repeat 4 times, rest between intervals 2 minutes, step 2 minutes in zone 1.

Warm-up: 10 minutes in zone 0.

Example 3:

Warm-up: 20 minutes in zone 0, 5 minutes in zone 2, 1 minute in zone 1 + 3 times 15 seconds fast in 45 seconds jogging. 1 minute in zone 1.

Work: 30 seconds fast, not at max, about 90%, 60 seconds jog, 4 minutes try at the end of zone 3 – 4. There are 6 series of these, with 5 minutes of jogging between series.

Warm-up: 20 minutes as slow as possible.

Any workout with oxygen consumption affects the growth of your VO2Max, even the lightest one, but the higher the consumption, the more effective.

How to Measure Your VO2 Max

The easiest way, but unfortunately inaccurate, is your running watch. Almost every gadget has a VO2Max determination formula embedded in it, which estimates your speed on flat ground and tries to predict your oxygen consumption. For the watch to surprise you with new figures, you need to run in ideal conditions all the time, as training, for example, on terrain or difficult ground, you will get negative figures.

In practice, most athletes’ watch and real numbers don’t add up because the watch can’t determine the exact amount of active muscle, your basal metabolism, the contribution of the anaerobic system, your economy (energy efficiency), what fuel source the system uses and in what proportion.

The watch simply averages your speed and shows you very average data, which cannot be used for conclusions or training planning. 

Metabolic Testing

It is an accurate method of determination, but not as accessible as simply calculating your hours. A metallography analyzes inhaled and exhaled air under exertion and at rest. The device determines the oxygen and carbon dioxide produced when you inhale and exhale air. The air passes through the entire transport system, entering the mitochondria and returning as oxygen or carbon dioxide.

Metabolism uses oxygen and releases carbon dioxide. Oxygen is needed to produce ATP during rest and exercise. You can break down stored fuel in your body for energy, but you produce a lot of carbon dioxide.

Not all carbohydrates, fats, and proteins contain the same amount of oxygen in the blood. This means that the different amounts of carbon dioxide and oxygen in your breath indicate the type of fuel you are burning.

For every liter of oxygen you get, you burn about five calories. So we know how many calories you burn and what energy source you use. We can calculate the respiratory exchange ratio by dividing the amount of carbon dioxide you produce or exhale by the amount of oxygen you consume or exhale. The method can have an error of three percent or less.

We can evaluate the entire metabolic system, which allows us to identify imbalances, determine intensity zones, and, most importantly, determine the energy consumption and fuel source. This will allow us to properly plan for the race and take a fresh look at the training process.

Common Mistakes in VO2 Max Training

1. Skipping Rest Days

Training hard every day without giving your body time to recover. VO2 max improves during rest, not just during workouts. Schedule at least one full rest day each week. If you feel extra tired, take an additional day off.

2. Overtraining with High-Intensity Workouts

Doing too many intense workouts, like sprints or hill repeats, without enough easy runs.
It can lower your VO2 max over time. Balance high-intensity workouts with slower, longer runs. Aim for 1-2 intense sessions weekly, and make the rest of your runs easy.

3. Ignoring Long Runs

Focus only on speed work and skip long, steady runs. Long runs help build endurance and improve oxygen use, directly boosting VO2 max. Include one long run each week. Start with a comfortable distance and slowly increase by 1-2 kilometers every week.

4. Poor Nutrition and Hydration

Not eating or drinking enough to fuel during intense training. You can’t perform at your best without proper nutrition, limiting your progress. Dehydration also reduces VO2 max performance. Eat balanced meals with protein, carbs, and healthy fats.

5. Lack of Variety in Training

Repeating the same type of workout every week. You adapt to the same routine, and improvement slows down. Diversify your training by including intervals, hill sprints, tempo runs, and long, slow runs.

6. Not Measuring Progress

Training without tracking your VO2 max or performance changes is difficult. Without measuring progress, it’s hard to know if your training is working. Record your results and look for gradual improvements.

Takeaways

A high VO2 max does not guarantee a great result, as it is important to consider how we use this oxygen and many other factors. But a high VO2 max is a prerequisite/potential for high performance in endurance sports.

In our tests, we often see athletes with equally high VO2max. Still, this figure alone, without knowing threshold levels and how a person uses energy, tells us nothing, so it is important to aim for a high VO2 max but also to consider other important factors:

• Maximum oxygen consumption (VO2 max)
• Lactate threshold
• The rate of lactate formation.
• Potential glycogen reserve
• Utilization of the energy source based on the needs of the race
• Economy/efficiency, which we can categorize into mechanical and metabolic

As Kilian Jornet (one of the best trail runners in the world with a VO2 Max above 90 ml/kg) emphasizes in an interview, “VO2 Max levels don’t say much without context: you can have a great engine but not have muscle adaptation or not know how to use the oxygen we absorb efficiently.