new Whoop 4 Accuracy Update
More: Detailed Whoop 4 Accuracy Review
Whoop released a series of accuracy updates during 2024, which I have here. There was also a further accuracy update on heart rate in January 2025. Have you noticed any difference?
Previous improvements covered the following four areas, but I haven’t noticed any material differences this year:
- HR estimation during sleep
- Improvements to accuracy in garment accessories
- Improvements to SpO2
- Improvements to heart rate estimation (assumed to be during activity)
2024 Experiences
Taking those in turn.
I did spot a possible rise in sleep HR in mid-2024, but only by one bpm, which could have been from other things than a simple firmware change.
Most Whoop garments come with a pouch for the Whoop pod; they all tend to be excellently made. The ASSOS cycling BIB shorts are high quality, and the HR measurements could be OK with the new algorithm (Results here). Previously, with the old algorithm using the Whoop calf sleeve, there were pretty good results but none as good as when wearing it with a biceps sleeve, which is the default wear position for me during exercise.
SpO2: I’m not interested in that data.
Rob (YouTube Link: Quantified Scientist) tested the old algorithm, and I asked him about the new one. Rob probably does the best, with the most scientific testing and mathematical correlations of heart rate data, and he now finds Whoop to be one of the most accurate devices. Most reviewers, myself included, at best usually compare multiple devices simultaneously across a variety of our usual training. The issue with optical HR is that accuracy depends on you, your training, your environment, and the technology, so you shouldn’t take any person’s view of the accuracy they experienced as correct for you.
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I believe whoop has quality control issues; of the five whoop devices I’ve had, only one is reasonable.
One had terrible HR accuracy, worse than the first gen wrist OHRMs. The slightest movement caused it to read very high, regardless of position on the upper arm. Another was very poor, worse than the first gen Scosche, but parts of a run could have a valid reading on the upper arm. Another two had jammed bands, so they couldn’t be taken off.
The fifth whoop is pretty good; not quite up to the verity sense, but generally usable as long as it’s on the upper arm.
interesting it’s so variable from one device to the next, I’d not heard that, thank you Jonathan
i’ve only had the one gen 4 device (extensive Hr charts in the review – https://the5krunner.com/2024/11/23/whoop-4-0-strap-review-best-discount/)
I get similarly good performance to @thequantifiedscientist https://www.youtube.com/watch?v=rlEsoMy-l4w
you say “Are they getting “reviewer special” devices that perform much better than retail units?” – A: not as far as i know.
“Is WHOOP providing incentives that bias reviews?” yes, they offer commission. But you can see in my review i include MANY raw data charts over various test conditions. the data is what it is…N=1
but others get less good results that’s optical hr I suppose.