Series 8 - Low power mode during workouts

[Wando64]

The series 8 can be configured to switch on Low Power Mode automatically during workouts.
I have read the information about this and there doesn’t seem to be any downsides to having it switched on, with the positive of having reduced battery usage during workouts.
Does anyone know more about this functionality?
How do they save battery without affecting functionality?
I can make guess about it like everyone else (i.e. less apps refresh, reduced CPU clock, etc…) but I would be interested in hearing from someone that knows for sure.
Thanks

 

[Howard2k]

Use Low Power Mode on your Apple Watch - Apple Support (CA)

Low Power Mode in watchOS 9 and later reduces the amount of power that your Apple Watch uses so that you can save battery life.

support.apple.com

Preserve more battery life with reduced GPS and heart rate readings​

When you do an outdoor walking, running, or hiking workout with the Workout app, you can have your Apple Watch take fewer GPS and heart rate readings. Reducing the frequency of these readings can extend your battery's use significantly during long workouts.

This feature is available with watchOS 9.1 and later on Apple Watch SE (2nd generation), Apple Watch Series 8, and Apple Watch Ultra.

 

[Wando64]

Use Low Power Mode on your Apple Watch - Apple Support (CA)

Low Power Mode in watchOS 9 and later reduces the amount of power that your Apple Watch uses so that you can save battery life.

support.apple.com

Preserve more battery life with reduced GPS and heart rate readings​

When you do an outdoor walking, running, or hiking workout with the Workout app, you can have your Apple Watch take fewer GPS and heart rate readings. Reducing the frequency of these readings can extend your battery's use significantly during long workouts.

This feature is available with watchOS 9.1 and later on Apple Watch SE (2nd generation), Apple Watch Series 8, and Apple Watch Ultra.

The bit about reduced GPS and HR readings is an additional setting, different from the one I was referring to.

Workouts in Low Power Mode​

When you use the Workout app in Low Power Mode, your battery lasts longer while metrics such as heart rate and pace are still measured.
You can turn on Low Power Mode in Control Centre or Settings, or you can have Low Power Mode turn on automatically:

1. Open the Settings app on your Apple Watch.
2. Scroll down, then tap Workout.
3. Tap Low Power Mode.
   
   Now Low Power Mode will turn on automatically when you begin any workout in the Workout app.

 

[Howard2k]

It's a bit confusing because there are two low power models.
My understanding is that there's a global watch Low Power mode, and there's a workout Low Power Mode.

The watch Low Power Mode turns off these features:

Low Power Mode turns off these features​

• Always On display
• Heart rate notifications for irregular rhythm, high heart rate, and low heart rate
• Background heart rate measurements
• Background blood oxygen measurements
• Start workout reminder

But the Workout Low Power Mode turns back on heart rate measurements, but at a decreased frequency.



So if you have the first LPM enabled but the second LPM disabled then you don't get the decreased frequency GPS and Heart Rate measurements. I believe you'd still lose AOD though because that comes from the first setting, but otherwise your workout measurements are unaffected.

 

[Duffman19]

I believe one down side is that it reduces the number of cellular pings ( if you have that model), so notifications, texts, and even incoming calls will be delayed. I’ve seen differing figures as to how often it checks, but not being able to receive incoming calls is a big bummer for me as my main reason for using an AW for workouts is to stay connected.