VO₂ Max Testing

VO₂ max is the maximum volume of oxygen your body can take in, deliver, and use during peak effort. We measure it directly using a cardiopulmonary exercise test, in which you wear a mask connected to a metabolic cart while you walk, jog, or cycle at progressively harder workloads until you reach your true maximum.

Unlike fitness watches and treadmill estimates — which infer fitness from heart rate or pace — a clinical CPET captures every breath of oxygen consumed and carbon dioxide produced. The result is a number expressed in mL/kg/min that tells you, with precision, how efficiently your heart, lungs, blood, and mitochondria work together.

The whole test takes about an hour. The peak effort itself is short — usually 8 to 15 minutes — and it ends when you can no longer sustain the workload. We tailor the protocol to your fitness level so the data is accurate without being unsafe.

Decades of large cohort studies have found that low cardiorespiratory fitness is associated with higher all-cause mortality than smoking, diabetes, hypertension, or coronary artery disease. Moving even one fitness category higher — say, from below average to average — meaningfully reduces long-term risk.

VO₂ max also predicts how well you'll function decades from now. The decline that arrives in your 60s and 70s starts from whatever level you build today. Patients who train aerobically and maintain a high VO₂ max tend to climb stairs, carry groceries, recover from illness, and live independently far longer than those who don't.

It's also the most useful number we have for prescribing exercise. Heart rate zones, ventilatory thresholds, and training intensities derived from a real CPET are vastly more accurate than the generic ranges built into most wearables.

• VO₂ max (mL/kg/min) — your peak rate of oxygen consumption
• Ventilatory thresholds (VT1 and VT2) — the points where your metabolism shifts from primarily aerobic to anaerobic
• Respiratory exchange ratio (RER) — confirms whether you actually reached a true maximum effort
• Heart rate response and recovery — how your cardiovascular system handles and recovers from peak load
• Personalized training zones for endurance, threshold, and high-intensity work

• Anyone serious about long-term health and longevity who wants a precise baseline rather than a wearable estimate.
• Athletes and active patients who want training zones built from real physiology.
• Adults in their 40s, 50s, and 60s who want to quantify and slow the natural decline in aerobic capacity.
• Patients with unexplained shortness of breath or fatigue, where CPET can help distinguish cardiac, pulmonary, or deconditioning causes.

• Plan on roughly an hour at the testing facility. Wear what you'd normally exercise in.
• After a brief warm-up, you'll wear a fitted mask while we ramp the workload — typically on a treadmill or cycle ergometer — until you reach your peak.
• Avoid hard training the day before, and avoid eating a large meal in the two hours before the test. Caffeine is fine if you normally use it.
• We monitor heart rhythm, oxygen saturation, and effort throughout. The test is safe for healthy adults; we screen for any cardiovascular contraindications during your evaluation.

Your VO₂ max is interpreted against age- and sex-matched percentiles, not absolute cutoffs. We're as interested in trajectory as in the number itself — where you sit today, where the literature suggests you should aim, and what training pattern will actually move you there.

Your ventilatory thresholds become the foundation for your training plan. Most patients leave with personalized zones for easy aerobic, threshold, and high-intensity work, integrated with the rest of your performance plan.

Reassessing every 12 months is usually enough to confirm whether the plan is working. Most patients who train deliberately see meaningful improvement within a year.

1. Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Netw Open. 2018;1(6):e183605.
2. Kokkinos P, et al. Cardiorespiratory Fitness and Mortality Risk Across the Spectra of Age, Race, and Sex. J Am Coll Cardiol. 2022;80(6):598-609.Cohort of 750,302 adults — each 1-MET increase in fitness was associated with a 13–15% lower mortality risk.
3. Lang JJ, et al. Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses. Br J Sports Med. 2024;58(10):556-566.