Why Is VO2 Max Getting So Much Attention?
If you follow longevity or fitness conversations, you've likely heard VO2 max described as one of the most important health numbers you can know. That's because research consistently links higher cardiorespiratory fitness with a longer life and lower risk of chronic disease.
The good news: VO2 max isn't fixed. You can improve it at almost any age.
What Is VO2 Max?
VO2 max is the maximum amount of oxygen your body can take in and use during intense exercise. It's usually measured in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min).
Think of it as the size of your aerobic "engine." A higher VO2 max means your heart, lungs, blood vessels, and muscles work together more efficiently to deliver and use oxygen.
Why Does VO2 Max Matter for Longevity?
Cardiorespiratory fitness is one of the strongest predictors of how long—and how well—you'll live. In a large 2018 study of more than 120,000 adults, people with the lowest fitness levels had a higher risk of death than those with the highest fitness levels, and the association was as strong as or stronger than that of well-known risk factors like smoking and diabetes.
VO2 max also naturally declines with age—roughly 10% per decade after age 30 in less active people. Building it now helps you maintain the energy and capacity to stay independent and active later in life.
How Is VO2 Max Measured?
- Lab testing: The most accurate method uses a treadmill or bike test while you wear a mask that measures the air you breathe
- Wearables: Many smartwatches estimate VO2 max using heart rate and pace data. They're less precise, but useful for tracking trends over time
- Field tests: Timed runs or walks can provide a rough estimate
How Can You Improve Your VO2 Max?
The most effective approach combines two types of training:
- Zone 2 training (steady, moderate cardio): Exercise at a pace where you can still talk in full sentences—like brisk walking, cycling, or easy jogging. Aim for most of your weekly cardio here to build a strong aerobic base.
- High-intensity intervals: Short bursts of hard effort followed by recovery. A well-studied example is the "4x4" workout: four rounds of four minutes at a hard effort, each followed by three minutes of easy movement. One or two interval sessions a week is plenty for most people.
Other habits that support your progress:
- Consistency: Steady effort over months matters more than any single workout
- Strength training: Stronger muscles support better performance and healthy aging
- Healthy body composition: Because VO2 max is measured per kilogram, reducing excess body fat can improve your number
- Recovery: Sleep and rest days help your body adapt to training
If you're new to exercise or have a heart condition or other health concerns, check with your provider before starting high-intensity training.
A Personalized Approach to Healthy Aging
Fitness is one piece of a bigger picture that also includes metabolic health, hormones, and nutrition. Understanding your baseline—through lab testing and provider guidance—can help you focus your efforts where they matter most.
If you're exploring a more personalized approach to longevity, you can talk with a Heva specialist here: Talk to a Heva Specialist
The Bottom Line
VO2 max measures how well your body uses oxygen—and it's one of the strongest predictors of a long, healthy life. With a mix of steady cardio, some harder intervals, and consistency, most people can improve it at any age.