COROS vs Suunto: VO2max compared
How COROS and Suunto estimate your VO2max, what each needs from you, what else they show and what independent studies say about accuracy.
| COROS | Suunto | |
|---|---|---|
| Called | VO2 Max | Fitness level (VO2max) |
| Algorithm | In-house EvoLab | Not named in current Suunto manuals |
| App | COROS app | Suunto app |
| From: Outdoor run | Yes | Yes |
| From: Walk | Not confirmed | Yes |
| From: Treadmill | No | Not confirmed |
| From: Bike (power meter) | Yes | Not confirmed |
| From: Resting test | Not confirmed | Not confirmed |
| From: All-day data | Not confirmed | Not confirmed |
| Fitness age | Not confirmed | Yes |
| Race predictor | Yes | Yes |
| Published accuracy studies | 0 | 0 |
| What you need to do | One continuous 25-minute outdoor run (Run or Track Run mode, no pauses) at or above 65% of heart rate reserve, then at least one such run every 90 days. Cycling: a steady 20+ minute ride with a power meter and heart rate. | Record a run or walk of at least 15 minutes with heart rate. On the Suunto Run the manual mentions runs only. |
Key differences
- Fitness age: Suunto shows one (not confirmed for the other).
- Both have 0 published accuracy studies that we found.
How each one works
COROS: Running VO2 max uses heart rate and pace from your recent outdoor runs. Since October 2026 there is also a cycling VO2 max from rides with power and heart rate data.
Suunto: The watch reads your heart rate response during recorded runs and walks, together with pace and movement data. Past runs and walks are also used, so the estimate gets better as you record more.
Which is better for VO2max?
For VO2max specifically, the best device is the one that sees your hardest efforts: if most of your training is outdoor running, both give an estimate (both use outdoor run). If you cycle with a power meter, walk more than you run, or want a resting test, check those rows above. Whichever you choose, compare the number with itself over time and with the norms for your age.
Accuracy studies
COROS
No published, peer-reviewed validation found.
Suunto
No published, peer-reviewed validation found.
Frequently asked questions
Is COROS or Suunto more accurate for VO2max?
Neither has published peer-reviewed validation that we found. Use either as a trend tracker, not a lab value.
Does COROS measure VO2max from outdoor run like Suunto?
Yes: both estimate from outdoor run.
Which is better for VO2max: COROS or Suunto?
Pick the one whose data sources match how you train: COROS uses outdoor run, bike (power meter); Suunto uses outdoor run, walk.
Built from official documentation (see each brand page for sources). Features vary by model and firmware. COROS and Suunto are trademarks of their owners; VO2max Health is independent and not affiliated with either.