Why VO₂ Max May Be the Most Important Number in Longevity Medicine

Written By Sam Hetz

When we talk about longevity, most people immediately think about cholesterol, blood sugar, blood pressure, or genetic risk. While all of these matter, there’s one variable that is arguably more predictive of how long you will live and how well you will function into older age -yet it's rarely measured in routine care:

VO₂ max.

What Is VO₂ Max?

VO₂ max stands for “maximal oxygen consumption” and refers to the maximum rate at which your body can take in, transport, and use oxygen during exercise. It’s typically measured in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min).

In practical terms, it tells you how hard your heart, lungs, blood vessels, and mitochondria can work together to support your body under stress. The higher your VO₂ max, the more efficiently your body can produce energy when it matters most.

Think of it as your aerobic engine capacity—and like any engine, one with more horsepower can go further, faster, and longer.

The Decline Is Inevitable - But It’s Modifiable

VO₂ max begins to decline by about 10 percent per decade after your 30s, and in sedentary adults, that number can be much higher. If you do nothing, by the time you're in your 70s or 80s, your VO₂ max may fall below the threshold needed for simple tasks like walking up stairs or carrying groceries.

But if you build a high aerobic reserve now, you can maintain independence and resilience well into older age.

To illustrate:

  • A VO₂ max of 55 mL/kg/min at age 35 might decline to 35 by age 75 - still functional.

  • But starting at 35 mL/kg/min in your 30s may mean dropping to under 25 by 75 - a level where frailty and dependency become real risks.

What the Science Says: VO₂ Max and Mortality Risk

1. Jaber et al., 2018 (JAMA Network Open)

In a landmark study of 122,007 patients, cardiorespiratory fitness was inversely associated with all-cause mortality.
Those in the “elite” fitness category had a fivefold lower risk of death than those with low VO₂ max. Importantly, there was no upper limit to benefit—the fitter you were, the lower your risk.
DOI: 10.1001/jamanetworkopen.2018.3605

2. Kodama et al., 2009 (JAMA)

This meta-analysis pooled data from 33 studies involving over 100,000 participants. Every 1-MET increase in VO₂ max (roughly 3.5 mL/kg/min) was associated with a 13 percent lower risk of all-cause mortality.
DOI: 10.1001/jama.2009.681

3. Mandsager et al., 2022 (Mayo Clinic Proceedings)

This study emphasized that even in older adults, higher cardiorespiratory fitness dramatically reduced hospitalization and cardiovascular death, reinforcing the importance of VO₂ max into advanced age.
DOI: 10.1016/j.mayocp.2021.07.010

4. Shibata et al., 2021 (JACC: Heart Failure)

Among elderly adults with heart failure with preserved ejection fraction, higher peak VO₂ was independently associated with lower mortality, regardless of comorbidities.
DOI: 10.1016/j.jchf.2021.02.016

5. Blair et al., 1989 (JAMA)

One of the earliest studies linking cardiorespiratory fitness and mortality. Low fitness was associated with three times higher risk of death, even after adjusting for smoking, cholesterol, and other risk factors.
DOI: 10.1001/jama.1989.03410180085036

6. Harber et al., 2017 (J Appl Physiol)

Compared older endurance-trained adults with sedentary peers and found preserved mitochondrial function and VO₂ max in those who trained regularly.
DOI: 10.1152/japplphysiol.00567.2016

How to Improve Your VO₂ Max

Improving VO₂ max is possible - at nearly any age - but it takes structured effort. Peter Attia, MD, and other longevity-focused physicians recommend a two-pronged approach:

1. Zone 2 Training (Aerobic Base Building)

  • Train at 60 - 70% of your max heart rate

  • Duration: 45 -60 minutes, 3 to 5 times per week

  • Builds mitochondrial density and fat oxidation capacity

2. VO₂ Max Intervals (Zone 5)

  • 4 -6 intervals of 3-4 minutes at 90-95% max heart rate

  • Equal recovery between intervals

  • Frequency: once weekly

  • Improves cardiac output, stroke volume, and oxygen delivery

These protocols improve not only performance but also clinical health metrics: blood pressure, insulin sensitivity, heart rate variability, and even cognitive performance.

Why We Test VO₂ Max at LifespanMD

At LifespanMD, we use clinical-grade metabolic carts to measure VO₂ max and ventilatory thresholds. This allows us to give clients:

  • A quantitative measure of cardiorespiratory fitness

  • Personalized training zones for precision exercise

  • A baseline to track progress over time

Testing takes under an hour and is one of the most actionable assessments in our practice. It tells us far more about your future health trajectory than most blood work ever will.

Conclusion

VO₂ max is not just for athletes. It’s for anyone who wants to maintain autonomy, vitality, and resilience into their 70s, 80s, and 90s.

It is one of the few physiological metrics that:

  • Predicts mortality risk

  • Can be accurately measured

  • Can be significantly improved with structured effort

If you’re serious about living better, longer - test your VO₂ max.

Sam Hetz
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