VO₂ Max Tracking
Monitor cardio fitness and mortality risk marker
What is VO₂ Max?
VO₂ Max (maximal oxygen uptake) is the maximum amount of oxygen your body can use during intense exercise, measured in milliliters per kilogram of body weight per minute (mL/kg/min).
It's considered the gold standard measure of aerobic fitness and cardiovascular capacity.
Why VO₂ Max Matters
VO₂ Max is a strong predictor of all-cause mortality - one of the most powerful markers of overall health and longevity:
- Higher VO₂ Max associated with lower risk of cardiovascular disease and death
- Reflects combined efficiency of lungs, heart, blood vessels, and muscles
- Declines with age and inactivity, but can be improved with training
- Used to assess fitness level and track training adaptations
Apple Watch VO₂ Max Accuracy
Important: Wrist-based VO₂ Max estimates are useful for tracking trends but may underestimate lab-measured values.
Recent validation studies (PLOS ONE 2025) show Apple Watch VO₂ Max estimates have non-trivial error compared to indirect calorimetry (gold standard lab testing) (PLOS ONE 2025).
What This Means:
- Absolute values may be inaccurate - Your Apple Watch VO₂ estimate may differ from lab testing
- Trends are still valuable - Changes in VO₂ Max over time reflect fitness improvements/declines
- Use for relative comparisons - Track your progress week-to-week, not absolute numbers
- Focus on training zones - Apple's Cardio Fitness levels (Low, Below Average, Average, Above Average, High) are useful for training guidance
VO₂ Max Ranges (General Guidelines)
Values vary by age, sex, and training status. These are general ranges for adults:
Men (20-29 years)
- <35 mL/kg/min - Low
- 35-43 - Average
- 44-51 - Good
- >51 - Excellent/Elite
Women (20-29 years)
- <28 mL/kg/min - Low
- 28-36 - Average
- 37-44 - Good
- >44 - Excellent/Elite
📉 Age-adjusted: VO₂ Max naturally declines with age. Use age-adjusted ranges for accurate assessment.
How Cardio Analytics Uses VO₂ Max Data
- Shows weekly/monthly VO₂ trends - Track fitness improvements over time
- Displays Apple's Cardio Fitness levels - Low, Below Average, Average, Above Average, High
- Encourages safe, progressive improvements - Gradual VO₂ increases indicate effective training
- Correlates with activity levels - See how training volume affects cardio fitness
⚠️ Focus on trends, not absolute values: Use VO₂ Max to track fitness direction (improving/declining) rather than comparing to published norms.
HealthKit Data Types
Cardio Analytics reads VO₂ Max data from Apple HealthKit using this identifier:
vo2Max- Maximal oxygen uptake (mL/kg/min) (Apple Docs)
Scientific References
- Lambe R, et al. Investigating the accuracy of Apple Watch VO₂ max measurements. PLOS ONE. 2025. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0323741
Track Your VO₂ Max with Cardio Analytics
Monitor cardio fitness trends and training adaptations with VO₂ Max tracking.
Download on App Store