Most high performance leaders that I know understand that they need to shift gears and get away from the day-to-day firefight once in awhile or they risk burning out. Quite a few of these leaders learned this lesson the hard way, succumbing at some point early in their career to the often self-imposed requirement to keep running at top speed out of fear of falling behind. A few cultures that I have been around actually encourage (or at least, don't discourage) this destructive pace, almost as part of some bizarre survival-of-the-fittest ritual. One of your core responsibilities to yourself and to your team members is to stay on top of your game mentally and physically (they go hand in hand). You owe it to everyone around you to be at your mentally sharpest when guiding, mentoring, helping with decision-making or engaging with colleagues. Just like the human body and brain needs sleep to function, I'm convinced that your effectiveness is function of giving your work-mind frequent and appropriate breaks to process and to recharge.