[layer8]

From my research, none of the available sleep tracking solutions are reliable, unless you attach electrodes to your head. When using multiple sleep tracking solutions in parallel, they all report significantly different results.

[mbirth]

Yes. Simply sleeping on the arm where you wear your watch will make it record crazy values.

The sleep quality and breathing measurements are based on movement - which doesn’t make sense when you have another person or pet with you in the bed that also tends to move at night.

That’s why we still have sleeping labs. However, the watch’s data can be an indicator that something is wrong and get people to at least mention it to their doc.