VO2 max sounds like a number for elite athletes to brag about. It is actually one of the most important health numbers you have, and improving it is less about racing and more about how well you age. Here is how to improve VO2 max, and why it might be the best longevity investment you can make.

What VO2 max is

VO2 max is the maximum amount of oxygen your body can use during hard exercise. It is a good proxy for the size of your aerobic engine. The higher it is, the more your heart, lungs and muscles can do before they tap out.

Why it matters more than any race

Large studies consistently rank VO2 max among the strongest predictors of all-cause mortality. One of the most recent ones is an Umbrella review in 2024 of 26 systematic reviews/meta-analyses (>20.9 million observations, 199 cohorts). High vs. low CRF: HR for all-cause mortality 0.47 (53% reduction). Dose-response per 1-MET: 11-17% reduction (HR 0.83-0.89). Very consistent protective effect. SOURCE

Fitter people, higher up the scale, die less and stay healthier. And here is the longevity punchline: VO2 max naturally falls by around 10% a decade after your thirties. The goal is to build a high enough ceiling now that ordinary life, stairs, hills, carrying the shopping, does not become hard as you age. Think of it as a biological insurance policy.

How to improve it

• A big easy base. Most of your training should be easy zone 2 work. This grows the engine’s foundation.
• Short, hard intervals. The classic is four rounds of four minutes near your max effort, with a few minutes easy between. Once or twice a week is plenty. This is what lifts the ceiling.

Beginners often see 10 to 20% gains in a couple of months. Progress slows as you get fitter, but it never stops mattering.

The honest part

Your watch’s VO2 max estimate is exactly that, an estimate, and it can wobble for silly reasons. Do not live and die by the number. Track the trend over months, not the reading after one bad run. And for long-distance performance specifically, your lactate threshold and running economy matter as much as VO2 max.

This is the same reason strength and balance matter as you age. See training to age well.