Best heart rate monitors for CrossFit and stop-start training

Why this category has an unusually clear answer

Most recommendations on this site come hedged, because most devices have never been measured. This one does not, because somebody ran exactly the right experiment.

The 2025 study in Sensors (n = 28, 14 male and 14 female) included a burpee protocol alongside rest, a cycling warm-up and a graded treadmill test. Burpees are the closest thing in the literature to a CrossFit stimulus: explosive, whole-body, with the wrist accelerating violently and the heart rate climbing and falling faster than any steady-state protocol produces.

The design was unusually clean. Three identical Whoop 4.0 units were worn simultaneously at wrist, forearm and upper arm, plus a Polar Verity Sense on the forearm and a Garmin Forerunner 55 on the wrist, all against a Polar H10 reference. Identical sensors at three positions removes brand from the equation entirely — any difference is caused by position alone.

What happened during the burpees

• Every optical device fell below 0.50 concordance. Not the wrist ones. All of them — including the forearm and upper-arm placements that won every other protocol in the study.
• The wrist-worn Garmin Forerunner 55 showed a bias of approximately 33 bpm, the largest error recorded anywhere in the paper.
• By contrast, on the graded treadmill the same Verity Sense armband recorded a bias under 0.1 bpm with a concordance of 0.997, and at rest everything agreed within 1 bpm.

That last bullet is the important one. These are not bad devices. They are devices whose measurement principle stops working under a specific stimulus, and that stimulus is your entire training session.

The mechanism, in one paragraph

An optical sensor infers pulse from light scattered back off moving blood. Three things break that during explosive work. The sensor shifts against the tissue with every impact, producing motion artifact the algorithm has to separate from the pulse signal. Whole-body movement is so violent that there is often no clean signal underneath to recover. And the heart rate itself is changing faster than the smoothing these algorithms apply can track, so even a good reading arrives late.

An electrical strap measures the heart's electrical activity directly, timing the R wave rather than estimating a rounded pressure wave that arrived through your circulatory system. It is a different class of measurement, not a better version of the same one, and that is why it survives conditions that break optical sensing.

What we deliberately left off this page

Armbands. We rank the Polar Verity Sense second on this site overall and it is an excellent device. It fell below 0.50 concordance in the burpee protocol along with everything else optical. Recommending it here would mean ignoring the one measurement that speaks directly to this use case, and the whole point of this site is that we do not do that.

Watches. No wrist optical sensor at any price has been shown to handle this. Upgrading from a cheap watch to an expensive one buys features, not a better heart-rate signal during burpees.

The cheapest strap on the site.The COOSPO H808S is an electrical strap and therefore has the right physics, and it is a quarter of the H10's price. It has no published validation of any kind. It appears in our full strap ranking because the principle is correct, but we will not put an unvalidated device on a page whose entire argument is that the evidence should decide.

The practical problems nobody mentions

Strap slippage. Sweat plus burpees plus rowing plus overhead work moves a chest strap. A strap that has slid down your ribs loses electrode contact and produces dropouts that look like erratic heart rate. Wet the electrodes before you start, and tighten it more than feels necessary — the correct tension is snug enough that it does not move when you jump.

Barbell and floor contact. Front rack position, floor presses and burpees all put load directly on the sensor pod. This is uncomfortable rather than damaging, and it is a real reason some people abandon straps. It is also the strongest argument for owning both a strap and an armband and using each where it works.

Gym equipment pairing. Many rowers, bikes and cardio machines listen for the old 5 kHz analog signal rather than Bluetooth or ANT+. Of the straps here, only the Polar H9 broadcasts 5 kHz analog — worth checking against the equipment you actually use before you buy. Our compatibility guide covers this platform by platform.

Class-display systems. Gym heart-rate display boards generally pair over Bluetooth or a proprietary receiver. Every strap here broadcasts Bluetooth, but if your box uses branded hardware, confirm before assuming.

The honest limits of the evidence

We are recommending straps here on the strength of one study with 28 participants, and the H10's position in it is as the referencerather than as a tested device — which means the study cannot measure the H10's own error. Being chosen as the criterion measure is a strong implicit endorsement by researchers, and it is not the same thing as having been validated.

Neither the Garmin HRM 600 nor the HRM 200 has any published validation we could find. They are here because they use the same physical principle as the reference and because platform fit is a legitimate reason to prefer one strap over another — not because anyone has measured them.

Burpees are also not CrossFit. They are the closest published proxy for it. Nobody has measured heart-rate devices during an actual mixed-modal workout with barbells, and we would rather name that gap than pretend the study covered your training exactly.

Choosing between the three

Buy the H10 unless you have a specific reason not to

It is the strap researchers use as their criterion measure, it pairs to Bluetooth and ANT+ simultaneously so it works with whatever you own, and Polar states 400 hours on a coin cell you replace rather than recharge. It also stores a session internally for up to 30 hours, which matters more than you would think in a gym where you left your phone in a locker.

Buy the HRM 600 if you are inside Garmin and want running dynamics

It adds metrics a watch alone cannot compute and stores data out of watch range. It costs meaningfully more than the H10 without a published validation advantage, and its extra metrics only fully surface inside Garmin Connect. That is a platform purchase, honestly described.

Buy the HRM 200 if you want the cheapest name-brand electrical strap

Electrical measurement, HRV data, a machine-washable strap — which, for training that involves this much sweat, is a more relevant feature than it sounds. No running dynamics and no published validation.

Do not buy a new watch

If wrist heart rate during metcons is the problem, no watch solves it. The published result is about optical sensing under explosive load, not about which brand made the watch, and the strap costs a fraction of a watch upgrade.