You’re cherry picking again…
You also get a huge reduction when you turn on SpO2 (off by default on Garmin, on by default on iWatch). Same for music, always on display, etc etc etc.
You also get a huge reduction when you turn on SpO2 (off by default on Garmin, on by default on iWatch). Same for music, always on display, etc etc etc.
The 20h number I mentioned is from the OP: "For continuous outdoor workout tracking, Apple Watch Ultra 3 now gets 20 hours of battery life in Low Power Mode with full GPS and heart rate readings." Low Power mode disables AOD and SpO2 (which is already disabled anyways during workout tracking).
I doubt SpO2 is very battery intensive either, certainly it can't be worse than the heart rate sensor. Both sensors work in the same way fundamentally.