VO₂ max by age and sex
These are the published median values from the 2015 US FRIEND registry: 7,783 maximal treadmill tests in adults without cardiovascular disease. Half of each study group was below its median and half above it.
| Age | Men | Women |
|---|---|---|
| 20–29 | 48.0 | 37.6 |
| 30–39 | 42.4 | 30.2 |
| 40–49 | 37.8 | 26.7 |
| 50–59 | 32.6 | 23.4 |
| 60–69 | 28.2 | 20.0 |
| 70–79 | 24.4 | 18.3 |
This is a specific historical study population, not a diagnostic threshold or Apple's classification table. FRIEND has since published updated standards. We identify the dataset so the numbers can be checked, rather than mixing different reference populations.
Kaminsky et al. · FRIEND (2015), Table 3 ↗How Apple Watch gets this number
Apple Watch estimates VO₂ max during eligible outdoor walks, runs and hikes. It combines sensor measurements with your health profile; it does not measure respiratory gases as a laboratory test does.
Check that your age, weight and other profile information are current. A blank day is not zero fitness: there may simply be no eligible estimate. Open Cardio Fitness in Apple Health and inspect the dates before comparing periods.
Use the table, then check the trend
Find your age row and the study's sex category that applies to the comparison. Being above or below a median describes where a value sits relative to that sample; it does not establish health, training readiness or an exact percentile.
For your own trend, use comparable periods and the same data source. Count the days with estimates and check whether a device, profile or recording habit changed. A short rise can be worth following without proving an improvement in fitness.
A comparison you can check
Two complete weeks. The same metric. Count the recorded days before interpreting the average.
| Period | Mean | Days recorded | Missing days |
|---|---|---|---|
| Week 1 | 39 | 3/7 | 4 |
| Week 2 | 41 | 3/7 | 4 |
This fictional example has three days with an estimate in each week. The average moves from 39 to 41. The other four days in each week are missing, not zero. Six observations alone do not establish a lasting trend.
Now ask about your own history
Connect telo to your assistant, then copy this question. Ask it to show the records behind the answer so you can check the dates, units and gaps.
Use telo to compare my VO2 max across the last two complete 28-day periods. Show dates, units, days with data and missing days for each period. Compare means and show the available daily values. Do not fill gaps, infer an exact percentile or diagnose a change. State whether coverage is sufficient for a comparison.Free covers the last 7 days. Comparisons with older history need Pro and the available records synced from your iPhone.
With your permission, telo syncs Apple Health records to its service. Records requested in a conversation are also processed by your chosen AI service.
Common questions
Is a VO₂ max of 40 good?
Age, sex, reference population and measurement method change the comparison. In this table, 40 is above the 37.8 median for men aged 40–49 in FRIEND 2015. That describes the study comparison, not a medical verdict on a watch reading.
Why is the Apple Health category different?
Different reference datasets and classification boundaries can produce different labels. This page shows study medians, not Apple's category boundaries. Check the category and profile shown in Apple Health separately.
Does telo measure VO₂ max?
No. telo reads the records available in Apple Health. If no source has recorded an estimate, telo cannot create the missing measurement.
Sources and method
- Kaminsky et al. · FRIEND (2015), Table 3
- Apple · Cardio Fitness
- FRIEND · Updated reference standards (2022)
Prepared by the telo team with AI assistance using the sources linked here. The reference tables describe their cited populations and methods. Examples are synthetic and their averages are computed from the downloadable records. This is educational material, not an individual assessment or a clinical review.