3 ms·
The other impediment to sleep tracking with Apple Watch is its heart rate measurements. One can get acceptable sleep tracking just from accelerometer data, but
by brlewis 9y ago
The other impediment to sleep tracking with Apple Watch is its heart rate measurements. One can get acceptable sleep tracking just from accelerometer data, but to get something like Fitbit's sleep tracking you need to measure heart-rate variability. Apple Watch's intermittent heart rate measurements (outside of workout mode) might make certain health metrics difficult to gather without killing the battery.
Theoretically Apple could catch up with Fitbit in this area at some point and achieve continuous 24-hour heart rate measurements.
- rhinoceraptor 9y agoThe apple watch measures heart rate every 5 minutes, and it does do HRV as of watch OS 4.
- brlewis 9y agoFitbit Ionic "Stores heart rate data at 1 second intervals during exercise tracking and at 5 second intervals all other times" - https://www.fitbit.com/shop/ionic#specs https://www.fitbit.com/shop/ionic#specs I don't know how much useful information you can get from the variability of a metric you only sample every 5 minutes.
- dkonofalski 9y agoThe parent's description isn't 100% accurate but it's accurate enough. The Apple Watch tracks every 5 minutes unless it detects an elevation in heart rate. If it detects something higher than 10 or 20 bpm, it polls more frequently. The standard, resting heart rate polling is at 5 minutes which, according to everything I've read, is more than accurate enough for most medical uses.