What Is VO2 Max and Why Is It Important?

If you've been involved in fitness, weightlifting, or anti-aging in any capacity over the past few years, you've probably heard the term VO₂ max. So, what exactly is VO₂ max, and do you need to worry about it? Well, a 2024 New York Times article said VO₂ max may be “the best piece of empirical information we have on health and longevity.”

Let's go over the basics of this health metric and help you determine if it's worth the trouble of getting your VO₂ tested.

The VO₂ max basics

In simple terms, the VO₂ max test measures how much oxygen your body absorbs during high-intensity exercise. Specifically, VO₂ max stands for Volume Oxygen Maximum, and the VO₂ max metric is expressed as a 2-digit number representing the milliliters of oxygen your body metabolizes per kilogram of body weight in 1 minute.^[1]

This test is performed during high-intensity aerobic exercise (usually running on an inclined treadmill, though other machines are sometimes used), so it needs to be performed in a laboratory setting with the test subject wearing a special respirator mask, and may cost several hundred dollars. It's also not covered by most insurance plans.

During the test, the subject typically begins walking at a comfortable pace on the treadmill, and the speed and/or incline of the treadmill is gradually increased with thegoal of reaching the subject's point of complete exhaustion, or maximal aerobic capacity. The VO₂ max test typically takes between 12 and 15 minutes.

The respirator mask, combined with computer sensors, captures and measures the amounts of oxygen that are inhaled and the amounts of carbon dioxide that are exhaled. These numbers are noted, along with your heart rate and treadmill speed, and your VO₂ max number is calculated.

What's a good VO₂ max number?

VO₂ max numbers, like any other metric of health or fitness, are really only valuable when compared to the “average” person of similar age, weight, and sex (and accounting for your current elevation, since that impacts oxygen levels). It can also be useful when comparing against your previous numbers over time to track improvement. High-level athletes often have their VO₂ max levels evaluated to help craft specific training regimens or measure the effectiveness of previous training protocols.

However, there are several charts and graphs showing what's generally considered an excellent, good, average, and poor VO₂ max number by age and sex. For example, according to this chart from Fitnescity, an 18-25 year old male with a VO₂ max number above 60 would be considered in excellent physical condition.

Generally, a VO₂ max of 42-46 would be average for this age group of men, and 30-36 is considered poor. Athletes in excellent condition often have VO₂ max numbers above 60, though top women have hit the high 70s, and some men have tested well into the 90s, with the male record-holder at an astounding 97.5 (Norwegian cyclist Oskar Svendsen).^[2]

Note that the VO₂ max charts are dependent not only on sex but on age. So, by 66+ years of age, our male subject would be considered to have an excellent VO₂ max number if it were greater than 37, using the chart above. Specific age ranges and estimations of “good” or “excellent” VO₂ max numbers can vary a little depending on which chart you consult, so look at a few sources to get a better picture.

Are there other reliable ways to test VO₂ max?

There have been several tests developed to approximate the results of a laboratory VO₂ max evaluation, and they may or may not be useful, depending on the level of accuracy you're looking to attain. The Cooper test is a well-known 12-minute running test that, according to the study author, can predict distance runners' finishing results fairly accurately, and can be correlated with VO₂ max numbers. Marathon Handbook has a good article regarding the potential value of the Cooper test. The Rockport Walk test is another “field” evaluation that is more easily (and less expensively) self-administered by people who don't want to undergo a laboratory VO₂ max test.

However, as the creators of these “estimation” tests will agree, they are not reliable determinants of your true, accurate VO₂ max number. There may be strong correlations, which can be sufficient for some people, but people who want their real VO2 number will choose to undergo the clinical oxygen uptake evaluation at maximum exertion.

Fitness apps, watches, and other wearables may also claim to provide a VO₂ max number. However, these are typically inaccurate and are marginal approximations at best. The only accurate way to determine your VO₂ max number is by undergoing the clinical/laboratory exertion test where your O2 uptake is measured until complete exhaustion.

However, a fitness watch or app providing a simulated or approximate VO₂ max number can still be useful, if you view it not as an accurate measure of your oxygen uptake but as a metric that you can track and see improvements. For instance, as people lose weight and improve aerobic endurance through regular exercise, their VO₂ max numbers almost always improve.

Similarly, a fitness app that estimates an approximate VO₂ max for you may motivate you to improve that metric as you continue in your fitness journey, and the app may reflect improvements in your endurance, heart rate, and weight (or other factors, depending on the app) as increases in the provided estimated VO₂ max number. This can be helpful if you enjoy setting and meeting health and fitness goals, even if the estimated number may not accurately align with a clinical VO₂ max test.

How can I boost my VO₂ max and my cardiovascular health?

Generally increasing your cardiovascular health and fitness through healthy weight management and regular exercise is known to improve VO₂ max numbers. However, if you are specifically interested in improving your maximum oxygen uptake during heavy exertion, high-intensity interval training (HIIT) is often recommended.

A 2013 study found that interval workouts improve VO₂ max faster than continuous aerobic workouts.^[3] A meta-analysis of 28 research papers showed low- and moderate-intensity training helped improve VO₂ max, but higher-intensity workouts required less time and overall training volume to boost VO₂ max.^[4] If HIIT isn't your bag, even alternating between several types of aerobic exercise during your workouts, and resting between, can be helpful in improving your VO₂ max.

Boost your VO₂ max with a science-backed supplement

For over 20 years, OxyDrene has been the go-to for weightlifters, fitness enthusiasts, athletes, and anyone who wants the cardiovascular, health, and performance benefits of improved VO2 levels. Powered by rhodiola rosea, niacin, and L-tryptophan, OxyDrene works in two ways:

• Increases VO₂ max and endurance*
• Boosts NAD+ and cellular energy*

NAD+ is a coenzyme that every cell in your body needs in order to produce energy. By middle age, your NAD+ levels could decline by nearly 90%. Optimizing VO₂ max and increasing NAD+ levels supports improved energy, mental focus, and cardiovascular health.*

As to why you should be working to increase your VO₂ max levels, Healthline puts it pretty clearly: “Based on research into the benefits of VO₂ max, the answer to this question seems pretty simple: It may help you live longer and with a higher quality of life.”