VO2 Max: Why This Number Predicts How Long You'll Live

What Is VO2 Max?

VO2 max is the maximum rate at which your body can consume oxygen during intense exercise. It's essentially a measure of how efficient your cardiovascular and muscular systems are at producing energy aerobically. The higher your VO2 max, the more aerobically fit you are.

It's typically expressed in milliliters of oxygen per kilogram of bodyweight per minute (mL/kg/min). An average sedentary adult in their forties might have a VO2 max of 30–35 mL/kg/min. An elite endurance athlete might be at 70–85 mL/kg/min.

Why VO2 Max Predicts Longevity So Powerfully

A landmark study published in JAMA Network Open followed over 120,000 adults and found that low aerobic fitness (VO2 max) was a stronger predictor of mortality than smoking, hypertension, diabetes, or cardiovascular disease. The effect was dose-dependent: each step up in fitness category was associated with 11–17% reduced mortality risk.

The difference in mortality risk between those in the bottom 25% of aerobic fitness and those in the top 25% was comparable to the difference between a current smoker and a non-smoker. This is an extraordinary finding.

Why VO2 Max Declines After 35 (And How to Slow It)

VO2 max declines at approximately 10% per decade in sedentary adults starting around age 25. After 35, cardiac output decreases, maximum heart rate declines, and oxygen-carrying capacity diminishes without intervention.

The good news: regular cardiovascular training dramatically slows this decline. Actively training adults may lose only 5–6% per decade compared to 10% for sedentary peers — a meaningful difference that compounds significantly over 20–30 years.

How to Improve VO2 Max After 35

Zone 2 Cardio: The Foundation

Zone 2 training — sustained, moderate-intensity exercise where you can hold a conversation but find it somewhat effortful — is the most effective way to build aerobic base for most adults. It improves mitochondrial density, cardiac stroke volume, and fat oxidation.

Target 150–180 minutes of Zone 2 cardio per week. Activities: brisk walking, cycling, swimming, rowing, or any sustained moderate-intensity activity. At Zone 2 pace, you should be able to talk in short sentences but not sing.

HIIT: The Accelerator

High-intensity interval training (HIIT) produces the most rapid improvements in VO2 max by pushing your cardiovascular system to its limits repeatedly. Short bursts (20–60 seconds) of near-maximal effort followed by rest periods of 2–4× the work interval.

One to two HIIT sessions per week alongside Zone 2 training is highly effective. More is not better — HIIT is stressful on joints and the nervous system, and adults over 35 need adequate recovery between sessions.

Coach Luc Tip

"VO2 max isn't just for elite athletes — it's for everyone who wants to be independent and physically capable in their 70s, 80s, and beyond. You don't need to train like an Olympic athlete to improve it. Consistency with moderate-intensity cardio will meaningfully improve your aerobic fitness over months and years."

— Coach Luc

Estimating Your VO2 Max Without a Lab

You don't need expensive equipment to estimate your VO2 max. Some wearable devices (Apple Watch, Garmin, Polar) estimate VO2 max from heart rate data during exercise. Alternatively, the Rockport Walking Test provides a reasonable estimate:

1. Walk one mile as fast as possible on a flat surface
2. Record your time and heart rate immediately upon finishing
3. Use the Rockport equation (available via our Fitness Assessment) to estimate VO2 max

Strength Training and VO2 Max

Strength training complements aerobic training for longevity in important ways. While strength training doesn't meaningfully increase VO2 max, it improves body composition (more muscle, less fat), which increases VO2 max per kilogram of bodyweight. Strength training also improves the muscular efficiency that supports aerobic exercise performance.

The optimal longevity training program combines both: use our Workout Generator to build a schedule that integrates strength and cardio in the right balance for your goals and available time.

The Bottom Line

If there's one number to improve for long-term health and longevity, it's VO2 max. The most effective strategy: a consistent combination of Zone 2 cardio (the majority of your cardiovascular training) and HIIT (one to two sessions per week), sustained over months and years. The investment compounds — and the return is a longer, more physically capable life.