[mauvehaus]

I don't know what Garmin you have, but I'm about half convinced that my Instinct's heart rate measurement is implemented by a PRNG. It's frequently off by 50% from a count/time cross-check.

It does not inspire me to move up their range when this watch eventually dies: if they can't get the basic feature working, I have a hard time seeing how they're going to manage anything trickier.

[iamacyborg]

Heart rate measurement on my Garmin (fenix 7 pro range) is great, the pulse ox measurements are shit though, and absolutely rinse the battery life.

[llm_nerd]

https://www.youtube.com/@TheQuantifiedScientist

That guy is a great reference, and through his videos you can find various measures where he compares devices against reference devices (e.g. the Polar H10 for heart rate for instance). A lot of the reliability of these devices relies upon a tight fit as well.

[alternatex]

Accuracy varies wildly with each model. Obviously the more expensive ($400+) ones are better, but Garmin devices are generally good with heart rate tracking. Same for Apple watch, Pixel watch, and a few cheaper options from Huawei and Xiaomi.

[jeltz]

Heartrate is generally very good but only as long as the fit is tight. Blood oxygen on the other hand is a joke.