I have to say from experience with both the Galaxy Watch and the Galaxy Watch4, and a competitor's fitness tracker with only a 70mAh battery, that this "continuous heart rate measurement turned on consumes oh-so-much energy, turn it off to save energy" sentiment is nonsense. The heart rate measurement pretty much doesn't affect the battery runtime on any wearable in my family at all. Not to mention that I disabled the -due to software issues that are desperately waiting to get fixed- faulty continuous measurement and turned it to the ten-minute setting about a week ago and thus have a reference. I use Always-on-Display with either the factory watchface (the "Premium Analog" one that says INITIAL at the top by default) or with the "Analog Dashboard" (according to taste), and it lasts exactly two days with the Always-on-Display enabled between 7am and 10pm. Guess how long it lasted with continuous measurement: Exactly, also exactly two days until it has to be recharged (battery being between 5 and 10 percent in both cases). These sensors consume so little energy and have been consuming so little energy for years at this point, that their setting doesn't actually matter in the slightest. I couldn't even get an hour of difference with the setting varied between being disabled, ten minutes or continuous.