Training

VO₂max: the number that predicts how long (and how well) you live

March 10, 20264 min read

If I could carve one number on the Lair wall to gauge my readiness, it would be VO₂max. It's not vanity: it's the metric that best tracks how long — and how independently — a person tends to live.

What the number means

VO₂max is the maximum volume of oxygen your body can take in and use per minute under intense effort. The higher it is, the more powerful your aerobic engine. Large studies link low cardiorespiratory fitness to a death risk comparable to — sometimes greater than — smoking or diabetes.

How to measure it

Lab: a masked cardiopulmonary exercise test, the gold standard.
Watches: wearables estimate it from heart rate and pace. Not precise, but useful for tracking a trend.
Field test: running the farthest distance you can in 12 minutes (the Cooper test) gives a fair estimate.

How to raise it (the part that matters)

A Zone 2 base: easy aerobic volume builds the foundation.
Long high-intensity intervals: the 4×4 protocol (4 min hard / 3 min easy, four times) is a proven VO₂max builder.
Consistency: the curve rises over weeks to months, not days. Stack sessions, not miracles.
Strength: muscle and heart play on the same longevity team.

The good news

Even from a low starting point, almost anyone can improve VO₂max with training. And the biggest survival gains show up exactly when someone climbs out of the least-fit group. In other words: starting already pays off.

A word from the Lair: this content is informational and does not replace medical care. A maximal exercise test requires medical clearance, especially with cardiovascular risk factors.

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