The “gold standard” for assessing cardiovascular fitness is VO₂ max, but for top athletes, it’s more than just a figure. Additionally, it can be a strong indicator of general health, longevity, and performance.
Knowing what affects your VO₂ max can help you take control of it, whether your goal is to track your progress, train more intelligently, or gain a better understanding of your long-term health risks.
This guide explains what VO₂ max is, how lifestyle and genetics affect it, and how much of it you can actually increase.
What Is VO₂ Max?
The maximum amount of oxygen your body can use during vigorous exercise is known as your VO₂ max, or maximal oxygen uptake. Millilitres of oxygen per kilogramme of body weight per minute (ml/kg/min) is the unit of measurement.
Simply put, it indicates how well your heart, blood, muscles, and lungs cooperate to supply and use oxygen, particularly when you’re exerting yourself physically.
A greater VO2 max typically indicates:
- Better endurance
- More efficient energy use
- Faster recovery
- Reduced chance of heart disease
It’s not limited to cyclists and runners. Nowadays, VO₂ max is commonly accepted as a marker of biological age and cardiorespiratory fitness.
- Genetics: The Starting Point
VO₂ max is genetically influenced, just like many other aspects of health and fitness. Indeed, research indicates that your genes may determine as much as 50% of your baseline VO₂ max.
Genes influence:
- Lung capacity and function
- Heart size and stroke volume (how much blood your heart pumps per beat)
- Mitochondrial density in your muscles
- Red blood cell production and oxygen-carrying capacity
- Your natural response to training (some people improve faster than others)
Your body’s ability to adjust to endurance exercise is influenced by certain genetic variations. Genetics frequently explains the difference between people who train hard but make slower progress and those who train little but perform well.
DNA, however, is not fate. It establishes the range, but you are in charge of what you do within it.
- Age and Sex: Natural Changes Over Time
Your VO₂ max peaks between your late teens and early 30s, and it usually decreases by 1% annually after that.
Because of physiological differences, men typically have higher VO₂ max scores than women:
- Greater size of the heart and lungs
- Increased levels of haemoglobin
- Greater lean muscle mass
However, these are averages rather than laws. Smart training and lifestyle changes can slow or even reverse the decline of VO₂ max with age, and a well-trained woman can easily outperform an untrained man.
- Training and Exercise Habits
This is where you have the most control.
Endurance training — especially activities like running, cycling, swimming, or rowing — directly improves VO₂ max by:
- Increasing stroke volume (the heart pumps more blood per beat)
- Building capillaries in muscles
- Improving mitochondrial function
- Boosting oxygen transport and use
The following are the best training methods for increasing VO₂ max:
- Zone 2 training: Extended, low-intensity aerobic exercise (increases efficiency)
- VO₂ max intervals: Short bursts of high-intensity effort (pushes max capacity)
- Tempo workouts: Consistent efforts that fall just short of your threshold
Depending on genetics and initial fitness, most people can anticipate a 10–25% increase in VO₂ max with regular aerobic training.
- Body Composition
Your body composition is a significant factor because VO2 max is measured in relation to body weight.
- More lean muscle helps you use oxygen more efficiently.
- More body fat (especially visceral fat) lowers relative VO₂ max, even if your absolute oxygen use is unchanged.
Therefore, without altering your heart or lungs, you can increase your VO₂ max score by improving your body composition through strength training, diet, and fat loss.
- Altitude and Environment
Your VO₂ max may also be impacted by where you train and live.
The air has less oxygen at higher elevations. Your body adjusts over time by making more red blood cells to carry oxygen; this is a reaction that top endurance athletes frequently attempt to elicit through “altitude training.”
By making breathing and oxygen exchange more difficult, heat, humidity, and air pollution, on the other hand, can all lower your VO₂ max during testing or performance.
- Sleep and Recovery
Training is only one factor that affects VO₂ max; another is how well your body recovers from that training.
Your ability to adapt and get better can be hampered by chronic sleep deprivation, poor diet, or high stress levels. Additionally, they may result in overtraining, fatigue, and inflammation, all of which can lower VO₂ max and performance.
To reach your maximum aerobic potential, rest, sleep, and recovery nutrition are crucial.
- Nutrition and Hydration
In addition to oxygen, your muscles require fuel.
- A diet high in iron, B vitamins, and complex carbohydrates promotes the production of red blood cells and energy.
- Iron deficiency can reduce haemoglobin and oxygen-carrying capacity, particularly in women.
- Dehydration can cause your heart to work harder and your VO₂ max to appear lower by reducing blood volume.
Optimising your nutrition helps your body deliver and use oxygen efficiently.
How to Measure and Improve Your VO₂ Max
Fitness trackers and predictive tests can be used to estimate VO₂ max, but lab-based testing with a treadmill or bike and a gas analyser yields the most accurate reading. The amount of oxygen you breathe in and out during incremental exercise is measured by this test.
Obtaining a baseline VO₂ max reading is worthwhile if you’re serious about tracking your long-term health or performance. It enables you to:
- Benchmark your current fitness
- Identify training zones
- Track improvements
- Predict endurance performance
- Assess longevity and cardiovascular risk
Final Thoughts
Although VO₂ max is practical, it is a scientifically supported figure that can provide you with a wealth of information about your body’s health and future.
Your habits greatly influence how high you can achieve, even though your genes lay the groundwork. Most people can increase their VO₂ max and reap the long-term health benefits that come with it with the correct training, recuperation, and lifestyle choices.
Be aware of your number. Work out with a purpose. Keep an eye on what matters.
References
- Medical News Bulletin – How VO2 Max by Age Relates to Genetics and Your Health
https://medicalnewsbulletin.com/how-vo2-max-by-age-relates-to-genetics-and-your-health/ - Genomelink – VO2 Max and Training
https://genomelink.io/traits/vo2-max-and-training - Cleveland Clinic – How to Measure and Improve it
https://health.clevelandclinic.org/what-is-vo2-max-and-how-to-calculate-it - American Heart Association – Importance of Assessing Cardiorespiratory Fitness in Clinical Practice
https://www.ahajournals.org/doi/10.1161/cir.0000000000000461