Fitbit Air VO2 Max: Does It Track It, and How to See Your Score
Run these workouts on your iPhone, or hands-free on Apple Watch. Get PEAKVO2 Yes, the Fitbit Air tracks VO2 max. It reports it as your Cardio Fitness Score in the Google Health app, using the same algorithms as the Pixel Watch 4. Because the Air is screenless and has no built-in GPS, it gives its most accurate estimate when you carry your phone on an outdoor run so it can pair pace with heart rate; worn without runs, it falls back to a rougher resting-heart-rate estimate shown as a range. The Air costs $99, and this core metric needs no subscription.
The Fitbit Air, launched in May 2026 as Fitbit's answer to Whoop, put full health tracking in a screenless $99 band. One of the first questions buyers ask is whether it does VO2 max, and if so where to find it. Here is exactly how the Air handles VO2 max, why yours might not be showing yet, how accurate it is, and how it stacks up against the Charge 6. For our full guide to Fitbit VO2 max across every model, see Fitbit VO2 max.
Does the Fitbit Air Track VO2 Max?
Yes. Like every current Fitbit, the Air reports a Cardio Fitness Score, which is Fitbit's name for its VO2 max estimate, in ml/kg/min alongside a Cardio Fitness Level that ranks you against people of your age and sex. What makes the Air notable is that it delivers this on a screenless 5-gram band, and it runs the Pixel Watch 4 algorithms for VO2 max and heart rate variability, so the estimation logic matches Google's current flagship watch rather than an older tracker.
How the Fitbit Air Estimates VO2 Max
The Air has an optical heart rate sensor but no built-in GPS, which is the single most important thing to understand about its VO2 max. It uses two methods:
- Run-based estimate (the good one). When you record an outdoor run with your phone along for GPS, the Air pairs your pace with your heart rate: covering more ground at a lower heart rate means a higher VO2 max. This is the estimate worth trusting.
- Resting-heart-rate estimate (the fallback). Worn day to day without qualifying runs, the Air estimates your score from your resting heart rate and profile. It produces a ballpark, often shown as a range rather than a single number, and it never actually sees you exercise.
So the Air can absolutely measure your VO2 max well, but only if you bring your phone on outdoor runs. Without that, you get the weaker resting estimate.
Why Your Fitbit Air VO2 Max Is Not Showing
If your Cardio Fitness Score is missing, stuck as a wide range, or not updating, it is almost always the GPS requirement. Work through these:
- Record an outdoor run with your phone. The Air has no GPS of its own, so leave your phone in a pocket or armband on a run of at least about 10 minutes. Indoor treadmill runs do not qualify.
- Enable location for the app. Google Health needs location permission to log GPS pace for the run.
- Give it a few sessions. The estimate refines over several qualifying runs; one short walk may only produce a range.
- Check the sync. Make sure the Air has synced to Google Health after the run, since the score is calculated and shown in the app.
Once a proper phone-GPS run lands, the range narrows to a single number and starts to trend.
How to See Your VO2 Max on Fitbit Air
- Open the Google Health app (the renamed Fitbit app) on your paired phone.
- From the Today tab, tap the heart rate tile.
- Scroll to Cardio Fitness to see your score, your level, and the trend.
If you only see a range, record an outdoor run with your phone as above, and it will resolve to a number.
How Accurate Is the Fitbit Air VO2 Max?
The Air is as accurate as its method allows. Its run-based estimate uses the Pixel Watch 4 algorithms, and independent research on run-based Fitbit estimates has found them landing within roughly 10 percent of a lab test, which is fine for tracking your fitness over time. Two limits apply:
- The optical sensor and phone GPS are the ceiling. Wrist optical heart rate struggles at high intensity and in the cold, and the run estimate depends on your phone's GPS being along.
- The resting fallback is much rougher. If you never run with your phone, you are seeing the resting-heart-rate estimate, which is a broad ballpark.
As always with wearables, the trend is the signal. Judge the direction over weeks, not a two-point change.
Fitbit Air vs Charge 6 for VO2 Max
If VO2 max is your main reason for buying, the difference between the two comes down to GPS.
| Feature | Fitbit Air | Fitbit Charge 6 |
|---|---|---|
| GPS | Phone GPS only | Built-in GPS |
| VO2 max method | Run-based with phone, resting fallback | Run-based without a phone |
| Screen | None (screenless band) | Touchscreen |
| Mid-run heart rate | On phone only | On the wrist |
| Best for | Whoop-style 24/7 tracking, lowest cost | Runners who want the sharp estimate phone-free |
The Charge 6 is the better pure VO2 max tool because its built-in GPS gives the run-based estimate without carrying a phone. The Air is the pick if you want screenless daily tracking at the lowest price and do not mind bringing your phone on runs.
The $99, No-Subscription Angle
The reason the Air got so much attention is its business model. Where a Whoop band is inert without its membership, the Air's core health tracking, including the Cardio Fitness Score, works on a one-time $99 purchase. The advanced layer, the Gemini AI coach and the Daily Readiness Score, still sits behind the optional Premium tier, so the free experience is the raw metrics rather than coaching.
How to Raise the VO2 Max the Fitbit Air Shows You
The Air shows you the number, it does not train it, and because it has no screen you cannot glance at your heart rate mid-workout, which is exactly when interval training needs it. So the hard sessions are run off your phone, where a guided interval app carries the session. VO2 max rises with high-intensity interval training, with the biggest gains from time near your maximum heart rate (Helgerud et al., 2007).
PEAKVO2 guides the Norwegian 4x4, 30/30, and other VO2 max protocols on iPhone and Apple Watch with heart rate zones, spoken cues, and automatic phases, so you get the mid-workout guidance the screenless Air cannot give, then watch your Cardio Fitness Score climb. Follow the full 8-week VO2 max training plan to structure it.
Raise the number your Fitbit shows you
PEAKVO2 runs the interval protocols that actually raise VO2 max, the Norwegian 4x4, Tabata, and 30/30, on iPhone and Apple Watch, with heart rate zones, spoken cues, and automatic phases. The guidance a screenless band cannot give. Three workouts free.
Get PEAKVO2 freeFrequently Asked Questions
Does the Fitbit Air track VO2 max?
Yes. The Fitbit Air reports VO2 max as your Cardio Fitness Score in the Google Health app, using the Pixel Watch 4 algorithms. For the accurate run-based estimate you need to record an outdoor run with your phone along for GPS, since the Air has no built-in GPS.
Why is my Fitbit Air VO2 max not tracking?
Almost always because it has not seen a qualifying outdoor run. The Air has no built-in GPS, so record a run of at least 10 minutes with your phone in a pocket or armband and location enabled. Indoor runs do not count. Until then you may see a wide range instead of a number, or nothing at all.
How do I see VO2 max on the Fitbit Air?
Open the Google Health app, tap the heart rate tile on the Today tab, and scroll to Cardio Fitness. If you see only a range, record an outdoor run with your phone and it will resolve to a single number and start trending.
How accurate is the Fitbit Air VO2 max?
Its run-based estimate uses the Pixel Watch 4 algorithms and lands within roughly 10 percent of a lab test in independent testing, good for tracking trends. The resting-heart-rate fallback, used when you do not run with your phone, is much rougher. Read the trend over weeks rather than the exact number.
Is the Fitbit Air or Charge 6 better for VO2 max?
The Charge 6 is better for VO2 max because it has built-in GPS, so it produces the accurate run-based estimate without carrying a phone. The Air needs your phone along on runs, but it is cheaper and screenless for 24/7 tracking. Both report the same Cardio Fitness Score.
Do I need a subscription for VO2 max on the Fitbit Air?
No. The Cardio Fitness Score, Fitbit's VO2 max, is part of the core tracking that works with the one-time $99 purchase. Only the advanced layer, the Gemini AI coach and Daily Readiness Score, requires the optional Premium subscription.
Keep Reading
- Fitbit VO2 Max: Where to Find It, How Accurate It Is, by Model
- Best Fitness Trackers for VO2 Max, Compared
- How to Improve Your Apple Watch Cardio Fitness Score
- VO2 Max Training Plan: The Science of an 8-Week Program
- VO2 Max by Age: Chart of Normative Scores and What's Good
References
- Helgerud J, Høydal K, Wang E, et al. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc. 2007;39(4):665-671. PubMed
- Mandsager K, Harb S, Cremer P, et al. Association of cardiorespiratory fitness with long-term mortality. JAMA Netw Open. 2018;1(6):e183605. PubMed