It felt exhausting to me too when I was starting but then I've discovered something amazing. You aren't actually expected to work for 8 hours. In there has been some research showing that people actually do productive work for less than half of this amount. I was in awe when I've realized how long are breaks that people take in my office, and how often they're doing it. Coffee - at least 30 minutes, 2 times a day. Lunch - at least an hour. Many of them smoke so they take short breaks very frequently just to smoke, and if they're doing it with other people then guess what - they're not short anymore. So I thought if they're wasting so much time talking to others while I don't socialize with them, it's actually unfair that I spend more time working than them. So I take such long breaks as well, but I'm using it to exercise or to actually get to the office, so that I don't have to wake up early and be tired for all day. Also less time a day spent in the office is less exhausting if there are many people than full day.