TL;DR — A 2018 JAMA Network Open study of more than 122,000 adults found that higher cardiorespiratory fitness was associated with significantly lower long-term mortality, with no upper limit of benefit observed. Being in the lowest fitness category carried a higher relative mortality risk than traditional risk factors like smoking, coronary artery disease, or diabetes in that cohort. VO2 max is trainable, and it's one of the most modifiable longevity variables.
VO2 max is the maximum rate at which the body can take in, transport, and use oxygen during intense exercise. It reflects the integrated capacity of the lungs, heart, blood, and skeletal muscle to deliver and consume oxygen. It is typically measured in mL of oxygen per kilogram of body weight per minute (mL/kg/min).
VO2 max is an aggregate measure — it reflects the "ceiling" of aerobic capacity at the whole-organism level. A higher VO2 max means the body can do more aerobic work before fatiguing.
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The most widely cited modern data on fitness and mortality come from a 2018 study published in JAMA Network Open by Mandsager and colleagues at Cleveland Clinic [1]. Key details:
These are observational data and cannot prove causation. But the effect size, dose-response relationship, and consistency with other cohorts make this a robust signal.
VO2 max typically peaks in the late teens or twenties and declines gradually thereafter — roughly 10% per decade in sedentary adults. The rate of decline is meaningfully attenuated in people who remain aerobically active.
This has two practical implications:
Several approaches exist, with varying accuracy:
For most people, a wearable-based estimate is sufficient for tracking changes over time. Clinical-grade measurement is worthwhile when precise baselines matter or when interpreting unusual results.
VO2 max responds to training — and the training that drives it most efficiently is a combination of:
The base work builds the infrastructure; the intervals push the ceiling. Programs that use only one or the other typically see less improvement than programs that combine both.
→ Read more: Zone 2 Cardio and Mitochondrial Health
VO2 max is powerful but not sufficient on its own. A longevity-oriented fitness profile also includes:
Treat VO2 max as one pillar among several, not as a solo metric to maximize at the expense of everything else.
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VO2 max percentiles are normed for age and sex. A value that is "average" for a 30-year-old may be excellent for a 70-year-old. When interpreting a score, compare against published age- and sex-adjusted percentiles rather than absolute numbers.
What is a good VO2 max? "Good" depends heavily on age and sex. Published percentile tables (for example, from the Cooper Institute or ACSM) provide age- and sex-adjusted normative values. A VO2 max in the top quartile for age and sex is generally considered excellent.
Can you improve VO2 max at any age? Yes. Observational and interventional studies consistently show that aerobic training produces measurable improvements in VO2 max at essentially any age, though the magnitude of response varies.
How often should I test VO2 max? Every 6–12 months is reasonable for most people — long enough to see meaningful changes, short enough to provide actionable feedback.
Is VO2 max or resting heart rate a better longevity predictor? VO2 max has a stronger and more consistent association with mortality in large cohorts. Resting heart rate is useful but carries less predictive weight.
Charles Kamen, MD earned his medical degree from Albert Einstein College of Medicine and completed his internal medicine internship at Yale-New Haven Hospital, followed by a neurology residency at Loma Linda University. He is board-certified by the American Board of Psychiatry and Neurology.
This article is for educational purposes and does not constitute medical advice. Consult a qualified clinician before starting a new exercise program, particularly if you have existing cardiovascular conditions.