spazzcat, AW See
https://support.apple.com/en-us/HT204666
Found on another site: supposedly from MS.
Microsoft Band heart rate sampling frequency
- Exercise modes (Run and Workout): Heart rate records every second
- Sleep tracking : 2 minutes on, 8 minutes off. Repeats throughout duration
- All other times : 1 minute on, 9 minutes off, and repeating the cycle
- Manual: You can force-check your heart rate at any time by tapping the Me Tile
Band and AW are NOT the same when it comes to HR. When I am asleep, the Band is also tracking my heart rate, including when the Band detects sleep with no input on my part.
Also, I have found the heart rate on the Band to be fairly accurate when measured against medical devices (like when I was in the ER last month). To be fair, I was at rest and not running on a treadmill.
The AW tries to do everything, the Band is much more focused. The Band works with IOS and Android, while the AW is IOS bound.