Polar H10 vs Garmin HRM 600: which strap to check your ring against

The one difference that matters

Both of these are good chest straps. Both read the electrical signal of your heartbeat rather than inferring it from light through tissue, which is why both are a tier above any ring or watch for heart rate during movement. For the job this site cares about - finding out whether your ring's numbers are trustworthy - there is one asymmetry, and it is not a specification.

The Polar H10 is the device researchers reached for. It was the criterion measurement in Dial et al. 2025, which put consumer wearables including Oura rings against a strap overnight (Physiological Reports, open-access full text with per-device results at PMC). Garmin's HRM 600 is newer and is not the device in that literature. Neither fact makes the Garmin worse at measuring a heartbeat; it just means a Garmin-based comparison at home is your own experiment, while an H10-based one repeats theirs.

The protocol itself - seven nights, both devices, what to write down - is on test your ring against a chest strap. What the published comparisons found is on smart ring HRV vs a chest strap.

Specs side by side

Coin cell vs rechargeable

This is the practical trade and it genuinely splits buyers. The H10 runs on a CR 2025 coin cell rated at about 400 hours in Polar's manual (Polar). You never charge it, you never find it flat, and once every year or two you swap a coin cell. The Garmin uses a rechargeable lithium-ion cell rated at up to two months at an hour a day (Garmin) - fewer consumables, one more thing on the charging pile.

For a seven-night ring comparison, the coin cell is the better behaviour: continuous overnight recording is a lot more hours than an hour a day, and a strap that cannot run flat mid-test is one fewer way for the test to fail. For daily training, the rechargeable is the nicer object.

HRV: what each one hands over

HRV is the metric most ring owners actually want to check, and it needs beat-to-beat (R-R) intervals rather than a smoothed heart rate. Both the H10 and the HRM 600 provide that to HRV apps - Garmin's press material lists real-time heart rate and heart rate variability (Garmin). The Wahoo is the one with a caveat: HRV works “with a compatible app”, and Wahoo's own app and bike computers do not display or record it (Wahoo).

One more thing worth knowing before you compare numbers: HRV is not a single quantity. Oura reports rMSSD averaged from five-minute samples across the night (Oura Support), while Apple Health's only HRV type is SDNN (Apple Developer). Compare like with like, or your test measures the metric definitions rather than the hardware.

Ecosystem and connectivity

The H10 carries Bluetooth, ANT+ and 5 kHz, which is as broad as this category gets: phones, watches, gym equipment and swim-capable 5 kHz receivers. The HRM 600's advantages concentrate around Garmin hardware, and it records an activity by itself and syncs afterwards, so a phone can stay in a locker (Garmin). The H10 can also store one session of up to 30 hours on its own.

If you already own a Garmin watch, the HRM 600 slots in with less friction and the Garmin-ring question is answered on best smart ring for Garmin users. If you own nothing else, the H10 talks to more things.

Fit, comfort and the wet-strap rule

Garmin publishes two strap sizes, XS-S and M-XL. Polar does not list sizes on the technical-specifications page we cite, so that row is a dash rather than a guess. Both are rated for water - 5 ATM for the Garmin, WR30 for the Polar.

The thing that ruins chest-strap data is a dry electrode. Wet the contact area before you put it on, every time. A strap that reads badly for the first ten minutes of every night will add noise to exactly the part of a ring comparison you care about.

Where the Wahoo lands

The TRACKR is rechargeable over USB-C, claims over 100 hours per charge, and carries Bluetooth and ANT+. It is a perfectly good training strap. It is the weakest of the three for checking a ring, for two reasons: it is not the device in the published studies, and its HRV depends entirely on a third-party app because Wahoo's own will not record it. If it is what you already own, use it - just read the HRV numbers knowing where they came from.

The verdict

• Checking a smart ring: Polar H10. It is the criterion device in the research, it cannot run flat mid-test, and it stores a session on its own.
• Training, with a Garmin watch: HRM 600. Rechargeable, records solo, and fits the ecosystem you already bought into.
• You refuse to buy coin cells: HRM 600 or the Wahoo. Both are rechargeable; only the Garmin gives you HRV in its own ecosystem.
• You want both jobs from one strap: the H10 does the training job fine, so if you only buy one, buy that one. The roundup of all three, scored, is on best chest strap for HRV.