[vadansky]

The whoop measures and averages your HRV over your deep sleep to give you one number.

The AppleWatch, at last time I researched, just gives you your HRV, NOW. And my impression is it's not really a useful number as a snapshot, since it varies so much during the day it's not really useful to know what it is at 10:40 AM EST.

[petesergeant]

My Apple Watch appears to have taken HRV measurements at 2 hour intervals last night overnight — is it a granularity difference then?

[vadansky]

I think the idea is it has to during your deep sleep specifically, which may or may not overlap with those 2 hour intervals.