The claim
“VO2 max is the single best predictor of how long you’ll live.”
Overhyped
Evidence confidence
Moderate
Fitness is strongly associated with survival in a large clinical cohort. That study used estimated treadmill fitness, not a direct VO2-max test or a universal comparison of every lifespan predictor. Observational associations cannot establish how much changing one measure extends life.
The facts
Heart and lung fitness is an important marker of health. A large treadmill-testing cohort linked higher fitness to lower mortality, but did not establish VO2 max as the single best predictor for every person.
What this means for you
Build activity you can sustain instead of treating one fitness score as a forecast of your lifespan.
Your next step
Choose a manageable activity such as walking and build a routine around it. An intense interval program is not required by this evidence.
Sources