Polar vs Garmin chest strap

Why this comparison is not a coin toss

Both brands sell electrical chest straps. Both measure the heart's electrical signal directly rather than inferring it from light bounced off skin, which is the reason a strap beats a wrist sensor in the first place. On physical principle there is nothing to choose between them.

The separator is in the research literature, and it is a peculiar kind of evidence. When scientists need a ground truth for heart rate in a wearables study, they have to pick an instrument and trust it. In the 2025 anatomical placement study of 28 participants, the reference was a Polar H10. In Dial et al. (2025), 536 nights across five devices, the reference was a Polar H10 single-lead ECG sampled at 1000 Hz. We have not found a published study that used a Garmin strap as its criterion measure.

Be precise about what that does and does not mean. It is nota measurement of the H10's error - by construction, a study cannot measure the error of its own reference. It is a revealed preference by the people whose results depend on choosing correctly, which is a different and in some ways better signal than a manufacturer's claim. It also means that if the H10 carries a systematic bias, every number on this site inherits it and we would have no way of knowing. We say that out loud on how we rank.

What Garmin's straps actually buy you

Garmin does not lose this comparison on measurement - it does not compete on measurement. It competes on what the strap does after it has measured, and for a Garmin watch owner some of that is genuinely valuable.

The HRM 600 adds running dynamics - cadence, ground contact time, vertical oscillation and the rest - which a watch alone cannot compute, and it stores data when you go out of watch range and syncs it later. Garmin's own lineup page positions the HRM 200 as the plain strap: heart rate and HRV data, a machine-washable band, the lowest name-brand price. Neither carries a validation study we could find, and the HRM 600 costs $53more than the H10 at today's prices without a published accuracy advantage to show for it.

The honest framing: you are paying Garmin for metrics and integration, and Polar for the measurement record. If your watch is a Garmin and you want running dynamics, that is a real reason and the HRM 600 is the right strap. If you want accurate heart rate, you are paying a premium for metrics most runners look at twice and never again.

What Polar's straps buy you besides the research record

Three things, all from Polar's own published specification. Simultaneous Bluetooth LE and ANT+, so one strap pairs to a watch and a bike computer at the same time. Internal memory for one session up to 30 hours, so the H10 can record a ride you did without a watch - the H9 cannot, and that is the entire specification difference between them. And up to 400 stated hours on a CR2025 coin cell you replace rather than recharge, which is the most underrated feature on a training sensor.

Polar is also the only one of the two brands that publishes a strap size chart. Its own figures give the Pro Strap in XS-S (a 60-68 cm strap fitting a 62-82 cm chest) and M-XXL (68-87 cm strap, 71-118 cm chest). That is the specification which decides whether a chest strap fits at all, and a strap that does not fit does not read. Our ownership guide for that is the H10 battery and strap guide.

The H9 is worth a line of its own because it has one specification neither Garmin strap publishes: 5 kHz analog transmission alongside Bluetooth and ANT+. That is the protocol old gym cardio equipment listens for. If your heart rate needs to appear on a treadmill console rather than only in an app, the H9 is the strap that does it - see best heart rate monitors for treadmill.

Compatibility is not the tiebreaker people expect

The most common reason people buy brand-matched is a fear that cross-brand pairing will not work. It does. Both brands transmit on ANT+ and Bluetooth, both standards are open, and a Polar H10 pairs to a Garmin watch exactly as a Garmin strap pairs to a Polar watch.

What does notcross over is the proprietary layer. Garmin's running dynamics surface fully only inside Garmin Connect; Polar's training-load model lives in Polar Flow. So the real compatibility question is not "will it pair" but "which platform do you want the extra metrics to land in". The full chart is in our chest strap compatibility guide, and the Garmin-specific field is at best heart rate monitors for Garmin.

The case for neither

A chest strap you do not wear measures nothing, and that is the failure mode we see most. If you know you will not strap something to your ribs, the measured alternative is an optical armband: in the 2025 placement study a Polar Verity Sense on the forearm recorded a bias under 0.1 bpm against the H10 on a graded treadmill protocol, with 0.997 concordance. That is strap-class data without the strap, and the comparison is at chest strap vs armband.

The decision, in one list

• Default: Polar H10.It is the instrument the research uses, it pairs to two devices at once, it records on its own, and it is cheaper than Garmin's equivalent.
• Garmin HRM 600 if you own a Garmin watch and specifically want running dynamics and out-of-range storage. You are buying metrics, not accuracy.
• Polar H9if you train on gym equipment that reads 5 kHz analog, or if you always have a watch running and will never use the H10's memory.
• Garmin HRM 200 if you want the cheapest name-brand electrical strap and the machine-washable band matters to you.
• Check the chest measurement before you order either brand. Polar publishes the chart; Garmin does not, in any form we could read.