“Which smartwatch measures VO2 Max most accurately?” is one of the hardest wearable questions to answer, because almost no one tests it against a proper laboratory reference. One person who does is The Quantified Scientist, a post-doctoral researcher running an ongoing study that compares wearable VO2 Max estimates to gas-analysis testing at a sports-medicine lab. Here’s what the early data shows — with the important caveats up front.
- ›In the early data, Samsung and Polar were the most consistent against the lab reference.
- ›Suunto was the furthest off in one case; Apple was the most inconsistent (badly over-estimating for one participant).
- ›Garmin and Coros were a mixed bag — good for one person, weaker for the other.
- ›The practical rule: trust your wearable’s VO2 Max as a trend, not an exact number — especially if you switch devices.
The early ranking, brand by brand
Two people each did lab reference tests (running and cycling VO2 Max) in Vienna, then wore devices from eight brands across a structured six-week protocol. Here is how each brand fared in that preliminary data:
| Brand | Preliminary signal | What the early data showed |
|---|---|---|
| Samsung | Strong | Most consistent across both participants — closest to the lab reference in the standout result. |
| Polar | Strong | A top performer for both; very close once a “sick-day” test is set aside. |
| Garmin | Mixed | Good for one participant, weaker for the other — decent but not standout yet. |
| Coros | Mixed | Reasonable for both, but under-estimated for one and over-estimated for the other. |
| Amazfit | Limited data | Only tested on one participant so far, where it did quite well. Too early to rank. |
| Google Pixel | Mixed | Middling; one data point couldn’t be retrieved, so read with caution. |
| Suunto | Weak | Furthest off for one participant (estimated roughly 44 vs a reference near 53). |
| Apple | Inconsistent | OK for one participant but the worst for the other (over-estimated) — and it must be worn all day to produce an estimate. |
The test data in this article comes from The Quantified Scientist — Rob, a post-doctoral scientist who benchmarks wearables against laboratory references. We summarise and add market context; the measurements are his. Watch the full breakdown: VO2 Max accuracy across 8 wearables → (The Quantified Scientist on YouTube).
Why this test is more trustworthy than most
Most “VO2 Max accuracy” videos show a single number from a single day. This study is built to remove that noise, which is what makes it worth citing:
- A real lab reference — running and cycling VO2 Max measured by gas analysis at a sports-medicine institute, not another watch.
- An ECG chest strap for most brands, so the test measures the VO2 Max model rather than differences in wrist heart-rate sensors.
- A repeated protocol — multiple runs per device over weeks, not one lucky reading.
One technical nuance worth knowing: Apple, Google Pixel and Samsung can’t pair with an external chest strap, so they were tested on their internal sensor. The Apple Watch also has to be worn all day to generate an estimate at all.
What it means for buyers
If VO2 Max accuracy specifically is your priority, the early front-runners — Samsung and Polar — span very different price points. Samsung’s Galaxy Watch line sits in the mainstream ~$300 range with full smartwatch features, while Polar’s Vantage is a training-focused watch that trades apps for battery and sports depth. Garmin and Coros remain strong all-round training watches even if their VO2 Max numbers were mixed here. The takeaway is not “only buy Samsung or Polar” — it’s that no wearable VO2 Max is a lab test, so buy for the whole package and read the number as a trend.
Want to match a watch to the exact features you care about? Try our free Smartwatch Finder →, or read how accurate smartwatch VO2 Max really is.
Frequently asked questions
Which smartwatch is most accurate for VO2 Max?
In this preliminary scientific test, Samsung and Polar were the most consistent against a lab reference. But with only two participants so far, treat that as an early signal, not a final ranking.
Is wearable VO2 Max accurate at all?
It’s best used as a trend — whether your number is rising or falling for you on the same device — rather than an exact figure. Absolute values can shift when you change device or sport. See our guide on how accurate smartwatch VO2 Max really is.
Why did Apple score poorly here?
For one participant the Apple Watch over-estimated significantly. It also relies on its internal sensor and needs all-day wear to produce an estimate. With only two people tested, this may change as the study grows.
Does the measurement method matter?
Yes. To isolate the VO2 Max model from heart-rate-sensor differences, most brands were paired with an external ECG chest strap. Apple, Pixel and Samsung can’t use one, so they ran on their internal sensor.
Sources
Test data: The Quantified Scientist — VO2 Max across 8 wearables (preliminary study, 2 participants). Market and pricing context added by Smartwatch Trends. See our research process.