I go for a 7-mile walk (which takes ~2 hours) every day, however my Apple Watch tends to end my day with 40-50% battery remaining (last night it ended at 47%).

I go for a 7-mile walk (which takes ~2 hours) every day, however my Apple Watch tends to end my day with 40-50% battery remaining (last night it ended at 47%). This is with medium brightness, prominent haptic, email notifications limited to VIPs, and only a few third party apps installed. I also generally get few text messages, so appointment reminders and delivery notifications aside, the watch is fairly quiet for most of the day. There was a period once where it was ending up at 5-10% at the end of the day, however that seemed to be the fault of some app in the background that was apparently thrashing. Powering off then re-powering on the watch got it back up to lasting ~1.5 - 1.8 days on a charge, and that's not recurred since. That said, I'm also a bit disappointed that Apple isn't pushing for the watch to be able to last 2 to 2.5 days on a charge, to cover the occasional case where you forget to charge it one evening.