Show Notes
Why Normal Labs Miss Your Fitness Decline
Brooks Leitner of VO Health on estimating VO2 max from blood, and why a clean lab panel can still hide falling cardiorespiratory fitness.
Watch/listen links and cut-accurate chapters will be added after the final cut is live.
Read the full guideStandard lab panels can look normal while cardiorespiratory fitness quietly declines. VO2 max is one of the strongest predictors of long-term mortality, yet it rarely shows up on a routine blood draw. In this conversation, Brooks Leitner of VO Health explains why the gap exists and what it would take to close it.
We also get into the science behind blood-protein estimates of VO2 max. These signals are genuinely interesting, but they are early. A blood-based estimate is not a substitute for cardiopulmonary exercise testing (CPET), and we keep that distinction clear throughout.
Top takeaways
What matters clinically
01
VO2 max tracks mortality risk more tightly than most numbers on a standard panel, and a normal lab result does not rule out a declining trajectory.
02
Blood-protein estimates of VO2 max are an early research direction, not a validated clinical tool, and should be read as interesting signal rather than a diagnosis.
03
CPET remains the reference standard for measuring cardiorespiratory fitness. A blood estimate may point you toward testing, but it does not replace it.
04
Fitness is worth tracking on its own terms. It does not cancel other risk factors like ApoB, blood pressure, or glucose, and those still need their own attention.
Chapters
Episode map
TBD
What VO2 max actually measures
Why cardiorespiratory fitness is a distinct axis of health, not a byproduct of a good lipid panel.
TBD
The blind spot in normal labs
How a clean panel can coexist with a declining VO2 max, and why that matters for longevity.
TBD
Inside the blood-protein approach
What VO Health is trying to estimate from blood, and where the biology is promising versus unproven.
TBD
Estimate versus measurement
How a blood-based number compares to CPET, and the limits of any proxy for gas-exchange testing.
TBD
Reading the number responsibly
How to treat an early-stage estimate without overinterpreting it or skipping validated testing.
TBD
What to track and act on
Practical framing for fitness alongside ApoB, blood pressure, and glucose, without overclaiming.