I've posted a couple of items that I liked. One was called "Learn How to Benefit from Play," and another was "Benefits of Being a Slow Study."
It's important that we budget time in our lives for down-time to have enough physical energy, and so that our minds function efficiently. Have you ever noticed, when you've pushed yourself beyond your normal capacity, how you find yourself making errors, getting irritable or emotionally fragile, forgetting pieces of data (names of those you know well, appointments, where you last put your keys, etc., etc.)
That's when it's time to stop and rest. Rest and recreation are not self-indulgent time intervals. In fact, the word "recreation" suggests "re-creation" or "re-building." It's NECESSARY -- so STOP being a martyred workaholic! It gets old -- for you and those close to you (how many times do they hear, "Oh God, I've got so much to do!"). So what? Think you're going to get some kind of medal when you've worked yourself into an early grave or medically-mandated leave?
Declare your independence from a no-win mindset and learn to TAKE TIME OFF. You may find you're more productive in the long run.
Mindful Teaching and Teaching Mindfulness: A Guide for Anyone Who Teaches Anything