VO2 Max: What It Is & How To Improve It

If you’ve ever checked your smartwatch and seen a VO2 max number, you may have wondered what it actually means—and whether it matters for your health and longevity. The answer is yes, it does matter. But it will mean more when you understand what VO2 max measures, what affects it and how to safely improve it.

Andrew Hills, DO, CAQSM, a sports medicine physician with Franciscan Health Indianapolis, points out that as people age, they want to maintain aerobic fitness to help support energy, endurance and independence.

“So VO2 max and maintaining muscle mass through strength training are the strongest predictors of how long and how well we’ll live later in life,” he said.

Key Takeaways: VO2 Max

• VO2 max is a measure of aerobic fitness. It shows how well your heart, lungs, blood vessels, and muscles work together to use oxygen during exercise.
• VO2 max can change over time. Age, genetics and health can affect your number. But you can help improve it with aerobic exercise, strength training, recovery and consistency.
• When you improve VO2 max, it may help build your functional reserve, support everyday activities and improve long-term fitness.

What Is VO2 Max?

VO2 max is a measure of aerobic fitness and how your body uses oxygen during exercise.

The VO2 max, which stands for maximal oxygen uptake, reflects how much oxygen your body can absorb, transport and use during intense exercise. Think of it as a measure of how well your heart, lungs, blood vessels and muscles work together during activity.

“It’s basically the engine that powers our oxygen going throughout our bloodstream,” said Dr. Hills. The stronger and more efficient the “engine” is, the better your body can deliver oxygen to working muscles when you exercise.

Simply put, a higher VO2 max means your body can use oxygen more efficiently during exercise. That’s a good thing.

Why Does VO2 Max Matter?

Whether you run, bike, hike or climb a flight of stairs, VO2 max reflects how efficiently your body uses oxygen during physical activity. It also shows your overall cardiovascular fitness. When your VO2 max is higher, it means you may have more capacity for everyday activities and physical stress, such as when you’re running a race.

Improving your VO2 max may also help if you have a chronic condition that affects your breathing, circulation or exercise tolerance. These conditions include COPD, heart failure or cardiovascular disease. VO2 max can help the body use oxygen more efficiently and build more reserves for everyday activities.

VO2 max isn’t just for elite athletes. It can provide useful information for anyone who wants to stay active and maintain their fitness by giving a snapshot of how well your body handles physical activity.

VO2 Max And Longevity: What’s The Connection?

Dr. Hills noted that many health experts consider VO2 max one of the most powerful indicators linked to longer life.

“VO2 Max is trainable,” said Dr. Hills. “No matter where you're at in your fitness journey, this is something you can improve upon with exercise. So even if your VO2 max is on the lower end, you can train to improve it. When you improve your VO2 max, you could potentially lower your risk for certain health conditions. And the other nice thing about it is there’s no limit to how high the VO2 max number can go.”

What does VO2 max have to do with longevity? First, a higher VO2 max doesn’t guarantee a longer life. But improving aerobic fitness may support long-term function, mobility and quality of life. You don’t need to become a competitive athlete to benefit. Even modest improvements in aerobic fitness can help your body become more efficient and resilient.

What Is A Good VO2 Max By Age?

VO2 max varies by age, sex, genetics, training status, body composition and health condition. It typically drops as a person ages, but regular exercise can slow the decline. Keep in mind that there’s more to VO2 max numbers than age.

VO2 max is often higher in younger adults

People in their 20s and 30s often have higher average VO2 max numbers. That’s because aerobic capacity tends to be stronger earlier in adulthood.

VO2 max usually drops with age

It’s normal for VO2 max to get lower over time, especially without regular aerobic activity.

Training can make a meaningful difference in your VO2 max

People who do regular aerobic exercise like brisk walking, running, cycling or swimming may have higher VO2 max numbers than less active adults of the same age.

Your VO2 max number matters most

A single VO2 max number is less useful than watching whether your fitness is improving, staying steady or getting lower over time. The most useful trend and comparison is often your own progress, not someone else’s.

Rather than focus on a single number, pay attention to how your VO2 max changes over time.

How Does A VO2 Max Test Work?

The most accurate VO2 max test is usually done in a clinical or sports medicine lab. You’ll exercise on a treadmill or stationary bike while the intensity slowly increases. At the same time, you’ll wear a mask or mouthpiece that measures your oxygen intake and carbon dioxide output.

The lab will also monitor your heart rate, breathing and how much you’re exerting yourself. The test goes on until you reach a high level of effort or the provider stops the test for your safety. A formal test can be helpful for athletes, people who are setting fitness goals or people with symptoms such as unexplained shortness of breath.

What about wearables for tracking VO2 max?

Fitness trackers and apps can come equipped to estimate VO2 max and their estimates can be useful for tracking trends over time.

“Wearable estimates may not be as accurate as lab testing and may differ by roughly 10 percent,” said Dr. Hills.

Wearables also are a tool that can track heart rate and activity patterns and give you insights that can guide your conversation with your provider. Fitness trackers help women stay heart healthy too.

What Factors Affect VO2 Max?

VO2 max isn’t a fixed “score” or personal “grade.” It’s more like a snapshot of how well your heart, lungs, blood vessels and muscles work together to use oxygen when you exercise. Your VO2 max is influenced by many factors, including your age, sex, genes, fitness level, body composition and overall health.

You can’t control some factors, such as age and genetics. Other factors can change over time, including:

• Aerobic exercise
• How you recover from exercise
• Strength training
• Whether you smoke
• Your sleep hygiene

Certain health conditions and medicines may also affect your VO2 max and how you or a provider should read your results.

That’s why a single VO2 max number shouldn’t be treated as a type of final grade. For many people, the most useful question isn’t “How do I compare with everyone else?” It’s “Is my aerobic fitness improving, staying steady or declining over time based on my VO2 max numbers?”

How To Safely Improve VO2 Max

Dr. Hills pointed out that aerobic exercise is the foundation.

“Progress gradually,” he said, “especially if you haven’t exercised in a while. Higher-intensity intervals can be effective, but they’re not the right starting point for everyone.”

Keep in mind that consistency matters more than doing the hardest workout possible. And if you have heart disease, lung disease, diabetes, high blood pressure or any new symptoms, you should talk with a provider before beginning intense exercise.

Dr. Hills suggests these training steps:

1. Start with an aerobic base

Aim for a pace where your breathing is elevated but controlled. You can begin with these aerobic exercises:

• Brisk walking
• Cycling
• Elliptical workouts
• Jogging
• Rowing
• Swimming

2. Add intervals when you’re ready

Do short bursts of harder effort followed by easier recovery to help improve VO2 max.

If you’re a beginner, you may want to start with 30-second to 60-second intervals.

More experienced exercisers may work toward longer intervals.

3. Consider the Norwegian 4x4 method, but be cautious

Dr. Hills describes a commonly studied practice:

• 10-minute warmup
• Four 4-minute intervals at about 85% to 90% of estimated max heart rate
• About 3 minutes of active recovery between intervals
• Typically done up to three times per week in research settings

This practice can be intense and isn’t for everyone. Slowly work up to your goal or seek guidance from a provider or sports medicine expert.

4. Strength train

Strength training helps build and maintain muscle mass and supports balance as you age. Include two or more days per week of strength training if you’re able. Doing strength training and aerobic fitness together helps support your body’s function, independence and longevity.

5. Make recovery a priority

• Get enough sleep
• Stay hydrated
• Eat a balanced diet with enough protein
• Take rest days
• Increase workout intensity gradually

Added Dr. Hills, “Not everyone is trying to become a high-performing athlete. But improving VO2 max can help build functional reserve and support everyday activities.”

When To Have A VO2 Max Test

Wondering if you should have a VO2 max test? A sports medicine specialist or primary care provider can help you decide whether formal VO2 max testing is right for you.

You can think about testing if you’re:

• Having unexplained breathlessness
• Interested in a supervised fitness baseline
• Managing a chronic condition and want guidance
• Returning to exercise after injury or illness
• Training for an endurance event
• Trying to improve athletic performance

“VO2 max can be a useful measure of fitness and health,” said Dr. Hills. “But it’s not the complete picture. The good news is that the number can improve with training. Start where you are and then build slowly while staying consistent.”  

If you do have a test, your provider may pair it with exercise guidance, rehab referrals or a personalized fitness plan.

Are you interested in improving your aerobic fitness? Do you have symptoms, such as shortness of breath, that make exercise difficult? Talk with a Franciscan Health primary care provider or sports medicine specialist about the safest next step.