" Observant Jews spend Shabbat praying, eating, walking, and spending time with family and friends. They’re on to something. This life is a marathon, not a sprint. In fact, each day is a marathon. Most of us don’t go to work for twenty minutes a day, run as fast as we can, and then rest until the next race. We go to work early in the morning, run as fast as we can for eight, ten, twelve hours, then come home and run hard again with personal obligations and sometimes more work, before getting some sleep and doing it all over again. That’s why I’m such a fanatic about doing work you love. But even if you love it, that kind of schedule is deeply draining. Not an athlete in the world could sustain that schedule without rest. Most athletes have entire off seasons. So if we’re running a daily marathon, it might help to learn something from people who train for marathons. "
― Peter Bregman , 18 Minutes: Find Your Focus, Master Distraction, and Get the Right Things Done