VO2 Max: How To Measure and Improve It

If you hang around folks who view cardio exercise as a way of life, you’ve probably heard the term “VO2 max” uttered more than a few times. Many consider the metric the best measure of fitness.

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But do you really know what VO2 max tracks? Or what qualifies as a good VO2 max score? We asked sports medicine physician Matthew Kampert, DO, to walk us through it.

What is VO2 max?

VO2 max reflects your body’s potential oxygen uptake, or how much oxygen it can absorb and use while getting pushed to the limit during a workout. To break the meaning down piece by piece:

V is for volume
O2 is for oxygen
Max is for maximum

VO2 max is expressed as a number showing how many milliliters of oxygen your body uses per kilogram of body weight per minute of exercise. (Yeah … it’s a mouthful.) Officially, it is shown as mL/kg/min.

So, why is this data important? Basically, it reveals your body’s power supply potential. That’s because as you breathe in oxygen, it fuels a metabolic reaction within your muscle cells. The process gives your muscles energy called adenosine triphosphate (ATP).

To put it simply: More oxygen pushing through your system equals more energy output.

“Your body needs more energy to work — and it gets that from the oxygen you take in,” explains Dr. Kampert. “Heavier breathing during exercise reflects your body’s increased use of oxygen and production of carbon dioxide, which is let out as you breathe.”

A higher VO2 max means you have:

Strong heart and lung function, which translates into a more efficient aerobic system to better fuel your muscles
Better ability for endurance activities
A good chance to live longer, as research shows a connection between high aerobic fitness and more candles flaming on your birthday cake

“VO2 max really gives you an objective view of your overall health,” he adds.

What is a ‘good’ VO2 max?

There’s no single number that defines a “good” VO2 max for everyone, given the many factors that affect the measurement.

For starters, studies show that VO2 max tends to naturally decline after age 30, dropping about 5% to 10% per decade. “A ‘good’ VO2 max won’t be the same for you in your 20s as in your 50s,” clarifies Dr. Kampert.

Your sex makes a difference, too, as men average higher VO2 max scores than women at the same age. What’s considered an excellent VO2 max for a 40-year-old man and a 40-year-old woman isn’t the same.

Put it all together, and it means assessing your VO2 max is very personal. So, what actually affects your VO2 max? A few key things:

How much oxygen your heart can pump: This depends on your heart rate and how much blood your heart can push out with each beat.
How well your lungs and blood move oxygen: Your lungs bring in oxygen, and your blood carries it to your muscles.
How efficiently your muscles use that oxygen: Muscle strength, mitochondrial health and enzyme activity all play a role.
Your genetics: About 40% to 50% of your VO2 max is determined by your genes. Training and lifestyle choices affect the rest.

Still, there are general ranges that reflect how your VO2 max measures up to your peers. The following charts offer a snapshot:

VO2 max chart for men and women on treadmill, with different ages, from superior to poor ranking data

How to measure your VO2 max

Many fitness trackers and devices estimate your VO2 max by using your heart rate. While those numbers aren’t exact, the results are typically pretty close, according to various studies.

For a more accurate measurement, your best bet is to take a graded exercise test at an exercise medicine lab. Dr. Kampert calls the test the “gold standard” for determining your VO2 max.

Here’s what to expect during the test:

You’ll wear a mask that captures your breath while you walk, run or cycle. The test records oxygen consumption and carbon dioxide production.
The test gradually gets harder until you reach your max effort.
The data collected shows how efficiently your body uses oxygen.

If lab testing isn’t an option, other tests — like shuttle runs, 12-minute runs or cycling protocols — can give you a rough VO2 max estimate. Just keep in mind that they’re not as precise.

Again, your score should be interpreted based on your age, sex and other factors. Small changes in your number (less than 3% to 5%) might just reflect natural test variability. That’s why it’s helpful to repeat the test over time and follow the same protocol each time.

How to improve your VO2 max

If your VO2 max isn’t where you want it to be, you can improve it. Starting or expanding a workout routine — particularly if it involves more heart-pounding cardio exercise — can boost your numbers.

That would include low-intensity, moderate-intensity and high-intensity activities like:

Losing body fat and building muscle can also raise your VO2 max. The reason why is simple enough: When you lose fat, your body can more efficiently deliver oxygen from your head to your toes.

If you’re just getting started on a workout program, a 10% to 15% improvement in VO2 max is realistic in just a few months. The key is to be consistent and gradually increase the intensity and duration of your workouts.

“Aim for progressive increases rather than absolute targets,” recommends Dr. Kampert.

Exercise should be tailored to your age, fitness level and health. It’s always best to talk with a healthcare provider before starting a program, particularly if you’re older or have existing health conditions.

A mix of high-intensity and moderate-intensity continuous training (MICT) activities often brings the most gains while reducing injury risk. (MICT involves doing a single activity for an extended time, like cycling for 45 minutes.)

Focus on improving your nutrition, sleep and stress, too, as well as recovery after workouts.

“Your VO2 max isn’t set in stone,” says Dr. Kampert. “It can change based on your body and your level of physical activity.”

Benefits of tracking your VO2 max

Your VO2 max offers a good baseline for your fitness and cardiovascular health.

If you’re an athlete in training, your score is a way to see whether your workouts are pushing your body to a higher level for better performance. A higher VO2 max essentially gives you a fuel boost.

As you might expect, professional athletes tend to max out their VO2 max. The highest VO2 max ever recorded belonged to Norwegian cyclist Oskar Svendsen and reached 97.5 ml/kg/min.

Most of us, of course, aren’t on that level, but that doesn’t mean there isn’t value in tracking your VO2 max. Pushing your number higher or even maintaining it as you age can play a huge role in your overall health.

A higher VO2 max can reduce your chance of:

Heart attack
Heart disease
Stroke
Dementia and cognitive decline

“A high VO2 max across the lifespan is the single most powerful marker of physiological reserve,” says Dr. Kampert. “Develop it early and maintain it consistently and you will measurably increase your years lived in good health.”