VO₂ Max and the Real Deal on Cardiovascular Training
Let’s cut through the noise: VO₂ max is important—but not for the reasons most people think.
You’ve heard experts like Peter Attia and Andrew Huberman call it the best predictor of longevity. You’ve seen athletes obsess over the number. You may have even had a coach or trainer mention it in passing. But here’s the truth: VO₂ max is valuable, yes. But it’s just one piece of a much bigger cardiovascular puzzle.
Whether you're an athlete chasing performance or someone trying to stay healthy and independent for the long haul, understanding VO₂ max (and cardiovascular training as a whole) can help you train smarter — and achieve better results.
What Is VO₂ Max?
Let’s start at the top. VO₂ max stands for “maximal oxygen consumption” — or more specifically, the maximum volume of oxygen your body can use per minute during intense exercise. It’s measured in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). Think of it as your aerobic engine size — the bigger it is, the more oxygen you can use to fuel movement.
The Fick Equation helps us understand what affects VO₂ max:
VO₂ = Cardiac Output (HR × SV) × (a-vO₂ difference)
In plain English, VO₂ is determined by:
How much blood your heart pumps (cardiac output), which depends on heart rate and stroke volume
How much oxygen your muscles extract and use from that blood (arterial-venous oxygen difference)
So it’s not just about your lungs — it’s about the efficiency of your heart, blood vessels, mitochondria, and muscles. This is why cardiovascular training improves VO₂ max through adaptations like increased stroke volume, capillary density, and mitochondrial efficiency.
Why a Healthy VO₂ Max Matters
Having a high VO₂ max doesn’t just make you a better runner — it’s one of the strongest predictors of longevity and cardiovascular health. Research shows that the minimum VO₂ max needed for independent living as we age is about:
13-18 mL/kg/min for men
12-15 mL/kg/min for women
Anything below that threshold increases the risk for loss of independence and chronic disease. For perspective, sedentary individuals tend to fall between 20–35 mL/kg/min, while recreationally active people often range from 35–50. Elite endurance athletes? Sometimes 70, 80, or even 90+.
But here’s the kicker: VO₂ max declines by ~1% per year after age 25. That means if you’re not actively maintaining or improving your cardiovascular fitness, you’re losing ground every year — whether you feel it or not.
A healthy VO₂ max means:
Better energy and stamina for everyday life
Lower risk of heart disease, stroke, and early mortality
Greater exercise capacity and recovery
Better cognitive and metabolic health over time
It’s not just about athletic performance — it’s about resilience and healthspan.
Letnes, J. M., Nes, B. M., & Wisløff, U. (2023). Age-related decline in peak oxygen uptake: cross-sectional vs. longitudinal findings. A review. International Journal of Cardiology Cardiovascular Risk and Prevention, 16, 200171.
VO₂ Max Isn’t the Best Predictor of Performance
Surprise: having the highest VO₂ max doesn’t guarantee you’ll win races or perform better.
Olympic champion Frank Shorter had a relatively modest VO₂ max, yet dominated competitors with better numbers. Why? Because he had incredible running economy and an elite lactate threshold.
VO₂ max tells us what your body can do. Thresholds and movement economy tell us what it actually does.
VO₂ Max Isn’t Just Heart and Lungs
If you only train your heart rate, you're missing half the picture.
VO₂ max is limited by multiple systems:
Central: Heart and lungs (cardiac output, ventilation)
Peripheral: Muscle and mitochondria (oxygen extraction)
This is where traditional cardio shines. It stimulates both central and peripheral adaptations:
Increases stroke volume (a bigger, stronger heart)
Builds more capillaries (better oxygen delivery)
Grows mitochondria (better energy use)
Improves pH buffering and waste removal
Why Strength Training Isn’t Cardio
Let’s clear this up. Just because your heart rate is high during strength training doesn’t mean you’re doing cardio.
True cardiovascular training requires:
At least 50% of muscle mass active
Rhythmic contraction/relaxation cycles
Proper breathing mechanics (not breath-holding)
Duration >2 minutes
Intensity >50% of VO₂ max (or ~65% HRmax)
From “Cardio Code” by Dr. Kenneth Jay
Most circuit-style lifting doesn’t check these boxes. In fact, many high-intensity weight circuits only reach ~35–60% of VO₂ max.
Bottom line: Lifting weights fast is not cardio.
Training to Improve VO₂ Max
To boost VO₂ max, you need a mix of intensity and consistency.
Use the 80/20 Rule:
80% of training = Zone 2 (Low to moderate intensity; 65–75% HRmax)
20% = High-intensity efforts (e.g. 4x4min intervals >85% HRmax)
This combination builds your aerobic base, then pushes your ceiling.
But Don’t Chase the VO₂ Max Number Alone
A higher VO₂ max is great—until it’s not. Some athletes hit elite VO₂ levels and never perform at world-class levels. Others, like Svendsen (with one of the highest ever recorded), never saw the podium.
Remember: Performance = VO₂ Max + LA Threshold + Economy + Mental Game + Etc.
Cardio Is the Foundation
VO₂ max isn’t the goal. It’s a byproduct of smart cardiovascular training.
Whether you’re training for a sport, recovering from an injury, or just want to live longer and stronger, cardio training is essential.
Build a program with progressive frequency, intensity, time, and type (FITT principle)
Prioritize movements like running, rowing, cycling, and cross-country skiing
Use metrics like HR, step count, RPE, and duration to gauge effort and progress
Final Thoughts
You don’t need to obsess over VO₂ max. But you do need to understand what it means, what it tells you, and how to train for the adaptations that matter.
Get your heart stronger. Get your mitochondria more efficient. Get your body better at using oxygen.
And if you want more direction? Check out my other blogs on:
Train smarter. Breathe deeper. Perform better.