The Economist Says You Should Track VO2 Max. Here's Why a Lab Test Beats Your Apple Watch.
When The Economist covers a fitness metric, it's no longer a biohacker obsession — it's mainstream. Their recent piece on VO2 max was triggered by something remarkable: Norwegian triathlete Kristian Blummenfelt recorded the highest-ever measured VO2 max score in a lab setting, reigniting conversation about what this number actually means and whether you should be tracking yours.
The short answer: yes. But there's a catch. The way most people track VO2 max — through a wearable — isn't giving them the data they think it is.
What VO2 Max Actually Measures
VO2 max is your body's maximum oxygen uptake capacity — the ceiling on how much oxygen your cardiovascular and muscular systems can consume and use during intense exercise. It's typically expressed in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min).
Here's why it matters beyond athletic performance: VO2 max is the single strongest predictor of all-cause mortality. Not cholesterol. Not blood pressure. Not BMI.
Dr. Peter Attia has been direct on this for years. In Outlive, he writes that moving from low cardiorespiratory fitness to above average is associated with roughly a 70% reduction in all-cause mortality. Low VO2 max is, as Attia puts it, more predictive of early death than smoking.
This isn't an athletic vanity metric. It's a longevity biomarker.
The Problem With Wearable VO2 Max Estimates
Apple Watch, Garmin, Polar, and other wearables offer VO2 max estimates. The keyword is estimate.
These devices don't actually measure oxygen consumption. They infer VO2 max from heart rate data during outdoor runs or workouts — using proprietary algorithms that make assumptions about your running economy, heart rate response, and effort level.
The accuracy problem is significant. Studies comparing wearable VO2 max estimates to lab-measured values consistently show errors of 20–30% — and sometimes more, depending on conditions, fitness level, and individual variation. A fit 45-year-old who gets a reading of 48 mL/kg/min from their Apple Watch might have an actual VO2 max anywhere from 34 to 58 mL/kg/min.
That's not a data point. That's a guess. And you can't make meaningful training decisions from a guess.
What a Lab Test Gives You (That a Wearable Can't)
A clinical VO2 max test — the kind conducted on a treadmill with a metabolic cart and direct gas analysis — measures what you're actually breathing. Real oxygen consumption, in real time, under controlled conditions.
At DexaFit Scottsdale, our VO2 Max test uses lab-grade equipment to deliver data you can actually act on:
Your Exact VO2 Max Score
Not an algorithm's estimate. A measured, calibrated number — the same type of measurement used in clinical research, including the studies Attia cites.
Precise Heart Rate Training Zones
Generic heart rate zones (the "220 minus your age" formula) are population averages that may not apply to you at all. A lab test identifies your specific aerobic threshold, anaerobic threshold, and Zone 2 ceiling with precision.
Zone 2 training — the low-intensity, fat-burning, mitochondria-building zone — is the cornerstone of most longevity-focused cardio programs. You can't dial it in without knowing where your threshold actually sits.
Fat vs. Carbohydrate Crossover
The metabolic cart tracks your Respiratory Exchange Ratio throughout the test, revealing exactly at what intensity your body switches from burning fat to burning primarily carbohydrates. This crossover point is critical for endurance athletes and weight-loss clients alike.
Biological Cardiovascular Age
Your VO2 max score benchmarks against peer data to give you a cardiovascular age — a number that reflects how your aerobic system is aging relative to your actual age.
The Difference Between Data You Can Act On and Data You Can't
Here's the practical reality: if your wearable says your VO2 max is 44, what do you do with that? You don't know if it's accurate. You don't know your Zone 2 threshold. You don't know if you should be training aerobically or anaerobically. You have a number with no precision and no context.
A lab test gives you a foundation:
Your true VO2 max score with clinical accuracy
Your exact heart rate zones for every training modality
Your fat-carb crossover for nutrition and endurance planning
A baseline you can retest against in 6–12 months to measure real progress
The difference between a wearable estimate and a lab result isn't just accuracy — it's the difference between feeling like you have data and actually having data.
What Improving VO2 Max Looks Like
The good news: VO2 max is highly trainable. Unlike some longevity biomarkers, you have significant control over this one.
Targeted Zone 2 training — long, low-intensity sessions that build mitochondrial density — is the most evidence-backed approach for improving VO2 max over time. So is VO2 max-specific interval training for more advanced athletes.
But neither protocol can be optimized without knowing where you're starting. The zones matter. The threshold matters. The baseline matters.
The Economist just told a mainstream audience that VO2 max is worth tracking. We'd push further: it's worth measuring — precisely, in a lab, where the data is accurate enough to act on.
Ready to Measure Yours?
At DexaFit Scottsdale, our VO2 Max test takes approximately 20–30 minutes on a treadmill, uses clinical-grade metabolic analysis equipment, and gives you the full report: exact score, training zones, fat-carb crossover, and cardiovascular age benchmarking.
Individual test: $125. Or bundle it with a DEXA scan and Strength & Power assessment in our Athlete's Edge Package ($279) — the complete performance baseline.
If Kristian Blummenfelt's record score made you curious about where you stand, that's a good instinct. Go find out.