Garmin HRM 600

What Garmin publishes

From the HRM 600 owner's manual: a rechargeable lithium-ion battery rated up to 2 months at 1 hour per day, 5 ATM water rating, an operating range of 0 to 40 °C and a 2.4 GHz radio. Garmin describes the strap as providing real-time heart rate and HRV data, running dynamics, and stand-alone activity recording — that last one meaning it keeps recording when your watch is out of range and syncs afterwards.

What running dynamics actually are

Cadence, ground contact time, ground contact balance, vertical oscillation, vertical ratio and stride length. A watch cannot compute most of them, because it is on your wrist and they describe what your torso is doing. That is the honest reason this strap exists.

Whether you need them is a different question. They are consistent within a device, which makes them useful as trends — is my ground contact time falling as I get fitter? — and they have no published validation from any manufacturer that we could find, which makes absolute comparisons between people meaningless. Most runners look at them twice and never again; the ones who use them well use them as their own baseline.

The comparison that matters

That last row is the one that decides our ranking. The H10 is not merely validated; it is the instrument other devices are validated against, including in the 2025 placement study and the 536-night HRV comparison we cite across this site. The HRM 600 uses the same measurement principle, which is a good reason to expect it to be fine — but "right principle" and "measured accuracy" are different claims, and our rubric only credits the second.

Who should buy it

• Garmin owners who want running dynamics.This is the cleanest way to get them, and the metrics surface properly only inside Garmin's platform.
• People who resent coin cells. Rechargeable is genuinely more convenient — as long as you remember to charge it, which a 400-hour coin cell never asks of you.
• Anyone who just wants accurate heart rate. Buy the H10 and spend the difference on anything else.

The battery arithmetic, against a coin cell

Garmin's stated figure is up to 2 months at 1 hour of use per day — roughly 60 hours of recording between charges. A Polar H10 states up to 400 hours on a CR2025 that costs a couple of dollars, which is about a year at the same usage.

For most people that difference is not decisive; it is a monthly charging habit against an annual battery habit. It becomes decisive on a long trip without power, or if you are the sort of person whose devices are discovered flat at the start line. Rechargeable is tidier; coin cells are the ones that never ask anything of you.

The storage feature, and when it earns its place

Garmin describes the HRM 600 as capable of stand-alone activity recording — it keeps recording when the watch is out of range and syncs afterwards. That matters in three specific situations: pool swims, where 2.4 GHz radio does not travel through water; gym sessions where the watch is on a bench rather than your wrist; and any activity where you do not want a watch on at all.

It is a genuinely useful capability, and it is shared with the Polar H10, which also stores a session on board. Neither strap has published validation of the recorded values — the storage is a convenience feature, not an accuracy one.

The honest ranking argument

This strap scores 9 on hardware and 6 on evidence in our rubric. That gap is the whole review: electrical measurement through the chest is the correct physical principle, and nobody has published a measurement of this device doing it. The H10 scores higher because it is the instrument researchers reach for when they need something to measure everything else against — a status no marketing claim can substitute for.