If you're traveling with a great company who really knows what they're doing, you're going to have a few sweet, sweet rest days on your trek. On these days, you stay put in the town you're in so that your body can adapt to the altitude. But that doesn't mean you do nothing at all on these days. A big thing on the mountain (for Everest summiters, as well), is to hike high and sleep low, which means you'll hike up at least 1,000 more feet in elevation and then come back down to where you're staying to sleep. This helps your body adjust better and reduces the risk of altitude sickness.
Thankfully, these rest-day hikes usually only last around one to two hours, and then you do have the rest of the day to explore, relax, and recharge.
Image Source: Caitlin Gallagher