Stop Worshipping VO2max

The mortality data everyone cites does show a profound relationship between aerobic fitness and survival. That part is undeniably real. Higher cardiorespiratory fitness (CRF) is consistently associated with substantially lower cardiovascular and all-cause mortality.

But here is the epistemic mistake that keeps getting glossed over in the optimization echo chamber:

Most of the massive epidemiological longevity studies did not directly measure VO₂ max using laboratory gas analysis.

Instead, the foundational datasets—including the heavily cited Mandsager et al. (2018) cohort of 122,000 patients and the Kokkinos et al. (2022) study tracking 750,000 veterans—measured treadmill performance in METs (Metabolic Equivalents of Task). They mathematically estimated aerobic capacity based on how much work the subjects could actually sustain ($1 \text{ MET} = 3.5 \text{ ml/kg/min}$).

What predicts survival is not your lab-measured oxygen ceiling, and it certainly isn't a smartwatch algorithm (which independent validation studies consistently show carry margin of errors ranging from 7% to 16%).

It is your functional capacity under load.

That distinction matters immensely. A treadmill MET score is a systems-level stress test. It reflects cardiac output, pulmonary efficiency, mitochondrial density, vascular integrity, muscular endurance, biomechanical coordination, and fatigue resistance. It is an integrated measure of human performance.

Direct VO₂ max, by contrast, is a physiological maximum under tightly controlled conditions. It is highly valuable for athletic performance science, but it is a proxy—not the direct foundation—upon which most survival curves are actually built.

Furthermore, when we look closely at the hazard ratios in the literature, the pattern of survival is aggressively non-linear:

The mortality benefit is incredibly steep at the low end and flattens out at the high end.

Moving from the lowest fitness tier to moderate fitness provides a massive, life-altering reduction in all-cause mortality (often slashing risk in half).

Moving from moderate to high fitness still offers highly meaningful protection.

Moving from high to "elite" yields heavily diminishing returns for lifespan.

In fact, the 2022 Kokkinos data observed that the lowest mortality risk plateaus at approximately 14.0 METs. Based on population distributions, a defensible "longevity threshold"—the point at which you have captured the vast majority of the survival benefit—translates roughly to:

Men: ~45 to 49 ml/kg/min (roughly 13 to 14 METs)

Women: ~38 to 42 ml/kg/min (roughly 11 to 12 METs)

Hitting these marks places you safely in the "High" fitness category for most age groups. Above this level, your mortality risk is already maximally minimized. Bleeding out of your eyeballs on an assault bike to push your estimated VO₂ max from 45 to 55 as a middle-aged man does not proportionally extend your lifespan. It just makes you a faster runner.

Beyond the top 10 to 20 percent of the population, the survival curve bends.

This is where the Centurion’s perspective matters.

At a fundamental biophysical level, we are energy flowing through structured information. Health is the maintenance of coherence under energy flux. Aging is thermodynamic drift—the gradual accumulation of entropy. Survival depends on whether our biological systems can maintain organized throughput in a noisy, degrading environment.

Cardiorespiratory fitness is profoundly protective because it improves this systemic coherence. It increases your body's energy throughput capacity while maintaining cellular and vascular structure. It enhances your allostatic capacity—your adaptability under physical and metabolic stress.

But biological coherence has thresholds.

Once your system can reliably sustain high energy flow without destabilizing (which is exactly what clearing ~12 to 14 METs proves), a higher physiological ceiling does not automatically equal more survival. The human body is not a video game leaderboard. It is a dissipative system maintaining order against entropy.

VO₂ max is a component of that system. It is not the system itself.

If your primary goal is healthspan and longevity, your training should be designed to clear the risk threshold. Build a broad enough functional aerobic base to exit the high-risk zone and firmly anchor yourself in the high-fitness tier.

After that, change your paradigm. Train for functional capability. Train for musculoskeletal resilience (as modern demographic data continuously shows, combining a robust aerobic base with resistance training reduces all-cause mortality significantly more than chasing either adaptation alone). Train for the sheer joy of movement, or train for a sport. But do not confuse the pursuit of elite athletic physiology with the pursuit of an extended human lifespan.

Physics is the law.

Biology dictates diminishing returns.

The curve always bends.

Optimize for coherence. Not for screenshots.

Primary scientifique sources

The Foundational Survival Curve (Mandsager et al., 2018): This JAMA Network Open study of 122,007 patients is the bedrock for the "survival curves" heavily cited by longevity influencers. However, its methodology is based entirely on estimated METs from Bruce Protocol treadmill tests, not direct VO₂ max gas exchange. It proves that the most massive mortality risk reduction occurs simply by moving out of the lowest fitness tier. (Link to study)

The Diminishing Returns & 14 MET Plateau (Kokkinos et al., 2022): This massive JACC study of 750,000+ veterans proved the "diminishing returns" argument. They found that moving from "Low" to "Moderate" fitness yields the steepest mortality reductions. Crucially, they noted explicitly that the lowest mortality risk plateaued at approximately 14.0 METs (~49 ml/kg/min), validating your threshold argument over the "more is always better" myth. (Link to study)

Aerobic + Resistance Synergy (Momma et al., 2022): Published in the British Journal of Sports Medicine, systematic reviews of cohort studies show that maximum mortality reduction is achieved only when moderate/high aerobic fitness is combined with muscle-strengthening activities, demonstrating that maximizing a single variable (like VO₂ max) is biologically inferior to whole-system resilience. (Link to study)