Heart rate or GPS more battery consuming during workout?

[SilentFisher]

Hello apple watch users,

I'm planning to go on very long hike this week - around 12 hours long. I know from experience that my S4 will probably die if I will let him control my heart rate and track my position via GPS. Question is, what will bring more impact for battery saving? Disabling GPS tracking or heart rate?

 

[michaelb5000]

I don't know, but I would guess HR monitoring, although there is a setting in activity to make that intermittent and not continuous. I would not use workout tracking for a 12 hour hike; so just use the watch as a watch and not turn on (or off) any tracking. Will you have your phone? I think the watch uses the phone GPS when available, so turning off GPS on the watch may not make much of a difference for that part.