TL;DR
- For raw heart-rate accuracy in 2026, the Polar H10 and Garmin HRM-Pro Plus are both research-grade chest straps and effectively tie. Validation work puts both ECG-based straps at near-perfect agreement with a clinical reference.[1][2]
- The Polar H10 is the device researchers reach for as the criterion. Against an ECG Holter it held 99.4% signal quality during high-intensity exercise.[1]
- Pick by ecosystem, not by accuracy. The H10 (about $90) maximises cross-app compatibility; the HRM-Pro Plus ($129.99) adds Garmin running dynamics and running power.[4][5]
- Either chest strap beats wrist optical heart rate during intervals. Wrist sensors lag and overshoot at abrupt intensity changes; chest straps stay within a beat or two.[3]
The Polar H10 and the Garmin HRM-Pro Plus are the two reference chest straps for serious heart-rate training. Both measure the electrical signal of the heart (single-lead ECG), so both are far more accurate than any wrist optical sensor during fast intensity changes. This comparison separates the accuracy question (a tie) from the buying question (ecosystem and metrics). All prices and specs verified as of 2026-05-25.
Verified comparison
| Spec | Polar H10 | Garmin HRM-Pro Plus |
|---|---|---|
| Price (USD) | ~$90 (€99.90 list)[4] | $129.99[5] |
| Sensing method | Single-lead ECG, 1000 Hz[1] | Single-lead ECG (chest strap)[5] |
| Connectivity | Bluetooth LE + ANT + 5 kHz; dual Bluetooth[4] | ANT+ and Bluetooth LE (dual)[5] |
| Extra metrics | Internal memory (one session, ~30 h)[4] | Running dynamics, running power, treadmill pace/distance[5] |
| Battery | Replaceable cell, ~400 h[4] | Replaceable cell, up to 1 year[5] |
| Validated accuracy | Criterion-grade vs ECG[1] | Strong agreement vs ECG (CCC 0.95-0.99)[2] |
The Polar H10 is the research reference
When sports scientists need ground-truth heart rate in the field, they reach for the Polar H10. In the Gilgen-Ammann validation, the H10 was tested against a medical ECG Holter across low- to high-intensity activities; the strap held 99.4% RR-interval signal quality at high intensity (where the Holter itself dropped to 89.8%) with a correlation of r = 0.997.[1] That is why so much downstream wearable research uses the H10, not a clinical ECG, as the comparison device.
The HRM-Pro Plus validates just as well
Garmin's chest straps are not a step down in accuracy. A validation across tactical-population training movements (rucking, cycling, circuit work) reported mean absolute percentage error of 1.96 to 3.73% and concordance correlation coefficients of 0.95 to 0.99 for the Garmin and Polar chest straps, with both clustered at the top of the tested devices.[2] For practical purposes the two straps agree with ECG and with each other.
Why a chest strap beats wrist optical HR
The accuracy gap that matters is not Polar versus Garmin; it is chest strap versus wrist. Optical wrist sensors infer heart rate from light scattered by blood flow (PPG), which is vulnerable to motion artefact, sweat, and reduced peripheral flow during hard efforts. In a multi-activity validation, a wrist-worn optical sensor showed a mean absolute error of 6.41 bpm (MAPE 6.82%) against the Polar H10 reference, while the same sensor on the upper arm dropped to 1.43 bpm.[3] During interval work, wrist HR lags the real rise and overshoots the recovery; a chest strap tracks the transition cleanly.
The real decision: which ecosystem
Both straps are accurate, so buy on connectivity and metrics. The Polar H10 is the more universal sensor: Bluetooth LE, ANT, a 5 kHz gym-equipment band, two simultaneous Bluetooth connections, and onboard memory for strap-only recording.[4] The Garmin HRM-Pro Plus is the better pick inside the Garmin world, adding running dynamics (vertical oscillation, ground contact time, stride length), running power, and treadmill pace and distance to a compatible watch, plus a battery rated up to a year.[5] Neither requires a subscription.
Decision frame
- Lowest price, broadest app and gym-equipment compatibility, strap-only recording: Polar H10.
- Garmin watch owner who wants running dynamics and running power: Garmin HRM-Pro Plus.
- HRV research or precise threshold work: either, with a slight edge to the H10 as the literature's default criterion.[1]
- You only train at steady state and never sprint: a good wrist optical may be enough, but a strap removes the doubt.
Accurate heart rate is only useful if the zones are set correctly. Pair either strap with the Heart Rate Zone Calculator and read Heart Rate Zones: Methods Compared for the method behind the boundaries.
Verified as of 2026-05-25. Prices vary by retailer and region; confirm on the vendor page before purchase.
FAQ
Is the Polar H10 more accurate than the Garmin HRM-Pro Plus?
Not meaningfully. Both are single-lead ECG chest straps validated at near-perfect agreement with a clinical reference.[1][2] The H10 is the device researchers most often use as the criterion, but the HRM-Pro Plus matches it for training purposes.
How much less accurate is wrist heart rate?
In validation work, a wrist optical sensor showed roughly 6 bpm mean absolute error against the Polar H10 during mixed activity, versus about 1.4 bpm on the upper arm.[3] The error is worst during fast intensity changes such as intervals.
Does the Garmin strap work with non-Garmin apps?
The HRM-Pro Plus transmits over ANT+ and Bluetooth LE, so it pairs with many apps and devices, but its running dynamics, running power, and treadmill pace and distance work fully only on a compatible Garmin watch.[5] The Polar H10 is the more universal sensor.[4]
Do either of these need a subscription?
No. Both the Polar H10 and the Garmin HRM-Pro Plus are one-time hardware purchases with no recurring fee.
References
- 1 RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise (Gilgen-Ammann et al.) — European Journal of Applied Physiology (2019)
- 2 Validation of Garmin and Polar Devices for Continuous Heart Rate Monitoring During Common Training Movements in Tactical Populations — Sensors / ResearchGate (2022)
- 3 Wrist-Worn and Arm-Worn Wearables for Monitoring Heart Rate During Sedentary and Light-to-Vigorous Physical Activities: Device Validation Study — JMIR Cardio (2025)
- 4 Polar H10 heart rate sensor (specifications and connectivity) — Polar (2026)
- 5 Garmin HRM-Pro Plus product page (price, running dynamics, ANT+/BLE) — Garmin (2026)