The ways that humans and horses recharge aren’t all that dissimilar, and it mostly has to do with being in a familiar place that allows for relaxation, and of course, sleep. For us, that’s being at home. For horses, it’s being in a field with friends or in their regular stall in their barn.
Horses don’t need to sleep for an uninterrupted 8 hours the way we do; since they are prey animals, they’ve evolved to be awoken easily and make a break for it if need be. Horses need far less sleep than humans, and sleep deprivation is uncommon (usually only seen in busy show horses who are always in a different place). They will lay down for deeper sleep but only require a few hours a week of this kind of sleep, and will lay down only when they have buddies to “keep guard” in the field or feel safe in their stalls.
Solitary horses tend to get less deep sleep than horses that live in groups (according to equine sleep researcher Sue McDonnell), since horses that live alone feel that they have to look out for themselves all the time and can’t allow on the buddy system. So, if you think your horse is running a little ragged and needs to charge his batteries…turn him out with his friends! You may think that he’s up grazing and socializing all night, but in fact, this will allow him to obtain the deep sleep that he needs.