You wouldn’t ignore your blood pressure. So why are you ignoring this?

If you could measure your body’s capacity for survival, would you?

You already track some of it:

Blood pressure.
Resting heart rate.
Blood glucose.
Temperature.

These numbers earn the title vital signs because they’re:

Quick to measure
Non-invasive
Predictive of health outcomes
Exécutable

But there’s another measure that meets—and often exceeds—those criteria.

It’s more predictive than most vitals you already know. It’s trainable.

And it’s repeatable. VO₂ Max.

What Makes a Vital Sign

In medicine, a vital sign must be:

Predictive — Reliably forecasts health outcomes or risk.
Repeatable — Consistent when measured under the same conditions.
Actionable — Can guide intervention and track progress.
Non-invasive — Safe and quick to measure.

By this definition, VO₂ Max qualifies in every category—often with fewer limitations than the metrics we routinely collect.

VO₂ Max vs. Traditional Vitals

  
    
        Criteria
        VO₂ Max
        Blood Pressure
        Glucose
        Heart Rate
      

    
        Predictive Power
        10
        7
        7
        6
      

        Repeatability
        8
        6
        5
        7
      

        Actionable / Trainable
        10
        7
        8
        6
      

        Non-Invasive
        8
        9
        9
        9
      

  

Why this matters: VO₂ Max shows ~3–5% variability in controlled labs, vs. 10–20% for BP depending on cuff, positioning, and pre-test conditions [4,5]. It’s also one of the few vitals you can improve 10–20% in a matter of months.

The Predictive Power

Large-scale studies confirm it:

Mandsager et al., 2018 — In 122,007 adults, cardiorespiratory fitness was the strongest predictor of all-cause mortality. Top quartile had ~70% lower risk of death; elite (top 2.5%) ~80% lower risk than the lowest quartile [1].
Kokkinos et al., 2022 — In over 750,000 U.S. veterans, each 1-MET increase (~3.5 ml/kg/min) in VO₂ Max cut mortality risk by 13–15%, independent of age, BMI, or comorbidities [2].
Kodama et al., 2009 — Meta-analysis of 33 cohorts: each 1-MET gain lowered all-cause mortality by 13% and cardiovascular events by 15% [3].
Ross et al., 2016 — Systematic review: low fitness carries higher mortality risk than hypertension, smoking, or diabetes in multiple cohorts [6].

Why It’s Been Overlooked

Historically, VO₂ Max testing required research-grade equipment and trained staff.

Medicine defaulted to resting measures like BP and HR—easier to collect in a clinic but less representative of what happens when your system is under load.

The problem: most health crises don’t happen at rest.

The Flaws in Familiar Vitals

Even trusted vitals have limitations:

Blood pressure — Can vary by 20+ mmHg from cuff size, positioning, caffeine, stress, or operator technique [4,5].
Glucose — Swings with the last meal, hydration status, or acute illness.
Heart rate — Changes with hydration, sleep, temperature, and stress.

Yet we make major decisions—sometimes starting lifelong medication—based on these numbers, even when precision is questionable.

Why VO₂ Max Should Be Your Base Layer

Think of it as the foundation under every other reading.

If your VO₂ Max is high—say, in the top 25% for your age and sex—you’ve built a reserve that strongly offsets other risks.

Imagine:

You get a borderline-high BP reading at your check-up. The cuff was a poor fit, you were stressed from traffic, and there was no rest period. Based on that one number, you’re prescribed a drug with side effects.

Now imagine the alternative:

You also know your VO₂ Max, measured in a lab. It’s in the top quartile—a range tied to drastically lower mortality and cardiovascular risk. You focus on training, Zone 2 aerobic work, and outdoor light exposure (which also lowers BP via nitric oxide release [7]).

A few months later, both your VO₂ Max and BP look better—without unnecessary medication.

Wearables: Useful, But Validate

Consumer devices estimate VO₂ Max from heart rate, pace, and sometimes HRV. They’re good for spotting trends, but have 10–20% average error vs. direct gas-exchange testing [8,9].

Accuracy depends on:

Steady-state conditions
Correct user data (age, weight, resting HR)
Activity type (running works best; cycling, swimming less so)
Brand-specific algorithms

Best practice: Use wearables for day-to-day guidance, but validate annually or biannually with a direct VO₂ Max test—especially if your goal is to reach or stay in the top quartile.

DexaFit’s Approach

We treat VO₂ Max like the foundational vital sign it is:

Direct measurement with metabolic carts—no algorithmic guesswork.
4-zone training model from your personal ventilatory thresholds.
6–9 month re-tests to track true adaptation.
Integration with body composition and other key metrics for a complete picture.

Know Before You Act

Before starting a prescription, injection, or surgery—know your VO₂ Max.

It’s your aerobic reserve, your functional capacity, and one of the strongest independent predictors of how long and how well you’ll live.

Testez-le. Entraînez-le. Retestez-le.

Treat it like your health depends on it—because the data says it does.

Références

Mandsager K, et al. JAMA Netw Open. 2018;1(6):e183605.
Kokkinos P, et al. J Am Coll Cardiol. 2022;80(6):598–609.
Kodama S, et al. JAMA. 2009;301(19):2024–2035.
Passarella S, et al. J Hum Hypertens. 2014;28(5):301–306.
Pickering TG, et al. Hypertension. 2005;45(1):142–161.
Ross R, et al. Prog Cardiovasc Dis. 2016;59(5):448–455.
Liu D, et al. J Invest Dermatol. 2014;134(7):1839–1846.
Dürr S, et al. Eur J Appl Physiol. 2019;119(6):1335–1344.
Hansen D, et al. JMIR Mhealth Uhealth. 2024;12:e49066.

Why VO₂ Max Is a Vital Sign (and Should Be Treated Like One)