POLAR
Pick Polar if
- Chest-strap HRV during training matters
- Recovery score + training load drive decisions
- You're not waiting for a Garmin OAuth flip
Polar vs Garmin
Polar's recovery and training load science is excellent. Garmin reads more signals: Body Battery, 24/7 stress, floors, AFib screening. Both record an ECG; only Garmin tells you what it found. Polar wins on chest-strap HRV accuracy; Garmin wins on signal breadth and battery life.
POLAR
18/33signals its devices cover
Sport watch / chest strap
vs
GARMIN
27/33signals its devices cover
Athletic / outdoor watch
QUICK VERDICT
Both brands target athletes. The decision comes down to depth versus breadth. Polar reads 18 of 33 signals with chest-strap-grade accuracy on HRV and recovery (when paired with H10). Garmin reads 27 of 33 different signals — Body Battery, 24/7 stress, AFib screening, floors — but HRV only from the optical sensor during sleep. If you train by HRV, Polar. If you live by Body Battery, Garmin.
COVERAGE BY CATEGORY
Where each brand actually wins
Per-category breakdown of health signals exposed by each vendor's developer API. The number is breadth, not quality.
SIGNAL BY SIGNAL
The full matrix
| Signal | Polar | Garmin |
|---|---|---|
| Heart & Vitals | ||
| Resting HR | ✓ | ✓ |
| HRV | ✓ | ✓ |
| SpO2 | ✓ | ✓ |
| Respiratory Rate | ✓ | ✓ |
| Skin Temperature | ✓ | ✓ |
| Body Temperature | — | — |
| Blood Pressure | — | ✓ via Index BPM |
| ECG recording | ✓ | ✓ |
| AFib detection | — | ✓ |
| Vascular age | — | — |
| Sleep | ||
| Sleep duration | ✓ | ✓ |
| Sleep stages | ✓ | ✓ |
| Sleep score | ✓ | ✓ |
| Sleep efficiency | ✓ | — |
| Sleep apnea index | — | — |
| Activity | ||
| Steps | ✓ | ✓ |
| Active minutes | ✓ | ✓ |
| Calories | ✓ | ✓ |
| Activities | ✓ | ✓ |
| Floors climbed | — | ✓ |
| Distance | ✓ | ✓ |
| Fitness & Recovery | ||
| VO2max | ✓ | ✓ |
| Training load | ✓ | ✓ |
| Recovery / Readiness | ✓ | ✓ |
| Body Battery | — | ✓ |
| Stress (continuous) | — | ✓ |
| Cardiovascular age | — | — |
| Body Composition | ||
| Weight | — | ✓ via Index S2 |
| Body fat % | — | ✓ via Index S2 |
| Muscle mass | — | ✓ via Index S2 |
| Hydration | — | ✓ via Index S2 |
| Bone mass | — | ✓ via Index S2 |
| Visceral fat | — | — |
Verified against vendor developer documentation and MyBodyAI backend code. This counts what a brand's API exposes, which is not the same question as what one device measures: the device catalog scores each model's own hardware, so its numbers differ.
Current Polar models Street X (2026), Grit X2 (2025), Loop (2025), Grit X2 Pro (2024), all 11 Polar devices
Current Garmin models CIRQA Smart Band (2026), Forerunner 170 (2026), Forerunner 70 (2026), Forerunner 570 (47mm) (2025), all 28 Garmin devices
WHICH ONE FOR YOU
Pick the one that matches your priority
GARMIN
Pick Garmin if
- Body Battery and 24/7 stress matter
- Multi-day battery and outdoor GPS matter
- You want AFib screening + floors covered
POLAR+GARMIN
Pick both if
- Garmin watch on the wrist 24/7
- Polar H10 chest strap during structured workouts
- MyBodyAI merges both feeds with richer-source-wins
FAQ
Frequently asked questions
Should I choose Polar or Garmin?
For most people it is one or the other. Both are daily-wear devices that track the same core things, heart rate, sleep and activity, so wearing both is redundant. Use the matrix above to pick the one that wins the categories you care about.
Which one tracks more health signals?
Polar tracks 18 of the 33 signals I compare, Garmin tracks 27. The matrix above breaks it down by category, and they often win different categories.
Is it worth switching from Polar to Garmin?
Only if Garmin wins the categories you actually care about. If you already own Polar and it covers your main goal, the upgrade is rarely worth it. The matrix above shows exactly what changes.
How did you compare Polar and Garmin?
From each brand's official spec sheets and support pages, cross-checked against independent hands-on reviews (DC Rainmaker, the5krunner, Tom's Guide). Signal-level edge cases are noted in the matrix, not hidden behind a single check mark.
WHERE TO BUY
Check prices at the source
Links to each vendor's store. None of them changed any pick above.
MORE COMPARISONS
Explore other pairs
OPTIONAL — IF YOU WANT MORE
Want one place that merges both feeds?
MyBodyAI is what I build with these signals — it pulls from any combination of the brands above and derives Biological Age and 12 health indices from the raw numbers. Free to try, no card. It's optional — the comparison above stands on its own.
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