The act of context-switching itself is tiring so the trick is to keep the amount of context-switching you do to a minimum. For example, during brief idle times

The act of context-switching itself is tiring so the trick is to keep the amount of context-switching you do to a minimum. For example, during brief idle times (e.g. while you're waiting for something to download/upload/compile), don't do stuff that requires you to concentrate hard. If you do, you're effectively "unloading" the previous context from your brain and replacing it with something else (e.g. dealing with email). Then, when the thing finishes downloading/uploading/compiling, you have to "reload" the original context. That's two context-switches that you don't really need to do. I used to be a trader, which requires a lot of high-pressure, high-focus context-switching, most of it interrupt-driven. During brief downtimes, we wouldn't try to get something else done - we'd let our brains relax by goofing off, talking about crap/sports/girls/whatever, shooting Airzooka or Nerf guns at one another, playing practical jokes, giving one another shit, etc. That sort of stuff doesn't require a context switch in your brain because you don't have to concentrade - you just let your brain relax (like letting a CPU sleep while it's waiting for input). When a work-related interrupt arrives, you just drop the goofing off and concentrate on work stuff again. It may sound like you're wasting time by not filling every minute of the day with productive work but, overall, you'll probably be more productive because, althought you're spending less time actually working, the quality of your work will be higher. Plus, you won't feel as exhausted at the end of the day/week.