VO2 Max on Apple Watch by Age: How to Read Your Cardio Fitness
Cofundador da Cora (YC W24). Investigador em IA e robótica com mais de 500 citações do Google Brain e da UC Berkeley.
The average VO2 max on Apple Watch — which it calls Cardio Fitness — is approximately 40–44 mL/kg/min for men and 35–38 mL/kg/min for women in their 30s. Apple Watch classifies this reading into one of four Apple-defined tiers (Low, Below Average, Above Average, High) based on age-and-sex percentiles. This page shows where your number falls against both Apple's own tiers and the clinical ACSM reference framework researchers commonly cite.
Apple Watch introduced VO2 max estimation in watchOS 7.2, calling it "Cardio Fitness." It was one of the first mainstream wearables to bring this previously lab-only metric to everyday users. Understanding what your number means — and what it doesn't — requires a clear look at how it's measured, what Apple's tiers actually represent, how those tiers relate to the clinical literature, and how to use all of this to guide training decisions.
How Apple Watch Estimates VO2 Max
Apple Watch estimates VO2 max using an algorithm that analyzes the relationship between your heart rate and your pace during outdoor walks and runs. Over at least 20 minutes of GPS-tracked movement, it infers how efficiently your cardiovascular system delivers oxygen to working muscles. The algorithm was validated against laboratory VO2 max testing and published in Medicine & Science in Sports & Exercise, showing a mean absolute error of approximately 3.5 mL/kg/min. [Source]
The estimate updates automatically after outdoor walks, runs, and hikes. No formal test is required. Results are most accurate when you run or walk at a consistent pace for 20+ minutes in moderate temperature conditions without carrying extra weight.
VO2 Max by Age — Men (mL/kg/min) with Apple Watch Tier and ACSM Clinical Reference
The Apple Watch Tier column shows the label Apple Watch actually displays. The ACSM Clinical Reference column shows the corresponding category from the American College of Sports Medicine's separate 6-category framework, used widely in research. Apple Watch does not display ACSM labels like "Good," "Excellent," or "Superior."
| Age | VO2 Max Range | Apple Watch Tier | ACSM Clinical Reference |
|---|---|---|---|
| 20–29 | <34 | Low | Poor |
| 20–29 | 34–40 | Below Average | Fair |
| 20–29 | 41–46 | Above Average | Good |
| 20–29 | 47–52 | Above Average | Excellent |
| 20–29 | >52 | High | Superior |
| 30–39 | <33 | Low | Poor |
| 30–39 | 33–38 | Below Average | Fair |
| 30–39 | 39–46 | Above Average | Good |
| 30–39 | 47–52 | Above Average | Excellent |
| 30–39 | >52 | High | Superior |
| 40–49 | <32 | Low | Poor |
| 40–49 | 32–37 | Below Average | Fair |
| 40–49 | 38–44 | Above Average | Good |
| 40–49 | 45–50 | Above Average | Excellent |
| 40–49 | >50 | High | Superior |
| 50–59 | <28 | Low | Poor |
| 50–59 | 28–34 | Below Average | Fair |
| 50–59 | 35–40 | Above Average | Good |
| 50–59 | 41–47 | Above Average | Excellent |
| 50–59 | >47 | High | Superior |
| 60–69 | <24 | Low | Poor |
| 60–69 | 24–29 | Below Average | Fair |
| 60–69 | 30–36 | Above Average | Good |
| 60–69 | 37–42 | Above Average | Excellent |
| 60–69 | >42 | High | Superior |
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Experimenta o Cora GrátisApple Watch tier boundaries are approximate and age-stratified; Apple derives them from population percentiles, not ACSM boundaries directly. ACSM categories from ACSM's Guidelines for Exercise Testing and Prescription (11th ed.). Apple's "Cardio Fitness Low" notification fires when VO2 max falls below Apple's age-specific "Low" tier threshold — see Apple Support HT213248.
VO2 Max by Age — Women (mL/kg/min) with Apple Watch Tier and ACSM Clinical Reference
| Age | VO2 Max Range | Apple Watch Tier | ACSM Clinical Reference |
|---|---|---|---|
| 20–29 | <27 | Low | Poor |
| 20–29 | 27–32 | Below Average | Fair |
| 20–29 | 33–37 | Above Average | Good |
| 20–29 | 38–42 | Above Average | Excellent |
| 20–29 | >42 | High | Superior |
| 30–39 | <26 | Low | Poor |
| 30–39 | 26–31 | Below Average | Fair |
| 30–39 | 32–36 | Above Average | Good |
| 30–39 | 37–41 | Above Average | Excellent |
| 30–39 | >41 | High | Superior |
| 40–49 | <24 | Low | Poor |
| 40–49 | 24–29 | Below Average | Fair |
| 40–49 | 30–34 | Above Average | Good |
| 40–49 | 35–40 | Above Average | Excellent |
| 40–49 | >40 | High | Superior |
| 50–59 | <21 | Low | Poor |
| 50–59 | 21–25 | Below Average | Fair |
| 50–59 | 26–31 | Above Average | Good |
| 50–59 | 32–36 | Above Average | Excellent |
| 50–59 | >36 | High | Superior |
| 60–69 | <18 | Low | Poor |
| 60–69 | 18–22 | Below Average | Fair |
| 60–69 | 23–27 | Above Average | Good |
| 60–69 | 28–32 | Above Average | Excellent |
| 60–69 | >32 | High | Superior |
Queres que o Cora te ajude com isto?
Experimenta o Cora GrátisACSM categories from ACSM's Guidelines for Exercise Testing and Prescription (11th ed.). Apple Watch tier boundaries are approximate and age-sex-stratified based on population percentiles. Apple's "Cardio Fitness Low" notification fires below Apple's age-specific Low threshold — not at the ACSM "Poor" boundary, though the two approximate each other.
What Your Apple Watch VO2 Max Tier Means
Apple Watch sends a "Cardio Fitness Low" notification when your VO2 max falls below Apple's "Low" threshold for your age and sex. Apple derives this threshold from age-and-sex-stratified population percentiles. It corresponds approximately to the ACSM's "Poor" category, though the exact boundary differs. This threshold is associated with meaningfully higher cardiovascular risk in longitudinal studies. A 2018 JAMA analysis of 122,000 participants found that low cardiorespiratory fitness was the strongest predictor of all-cause mortality among the risk factors studied, stronger than smoking, hypertension, or diabetes. [Source]
Apple's "Below Average" tier spans the lower-middle range of the population (approximately ACSM "Fair"). "Above Average" is a broad Apple tier covering what researchers call "Good" through "Excellent" territory — consistent aerobic training typically lands you here. Apple's "High" tier, the top of Apple's display, corresponds approximately to the ACSM "Superior" category and is typically found in people who train aerobically 4–6 days per week. See the detailed breakdown on our Apple Watch Cardio Fitness explained page for what each tier means practically, and the parent VO2 max by age guide for broader population context.
What This Means for Your Training
VO2 max is the most clinically predictive fitness metric Apple Watch tracks — more predictive than resting heart rate, HRV, or step count for long-term cardiovascular health outcomes. If your number is in the Low or Average range, the single most impactful thing you can do is build consistent aerobic volume. Research shows that 150–200 minutes per week of Zone 2 exercise produces measurable VO2 max improvements within 6–12 weeks for most adults.
If you are already in Apple's "Above Average" tier, the strategy shifts. Moving toward the upper end of "Above Average" or into "High" requires adding 1–2 high-intensity interval sessions per week on top of your aerobic base. Reaching Apple's "High" tier (corresponding clinically to "Excellent" or "Superior") typically requires 3–4 weekly aerobic sessions plus structured intervals — the kind of progression that benefits from tracking your trend carefully to avoid overreaching.
Cora tracks your Apple Watch Cardio Fitness trend alongside your training load and recovery data to help you understand whether your current training is moving your VO2 max in the right direction. For the related HRV picture, see HRV by age on Apple Watch.
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