Daniel H Pink was asked:

What would you say to someone who says, “Oh, I don’t have time for a break. I’ve got too much to do”?

His answer:
If I want to be really glib, I say, “You don’t have time not to take a break.” I would use myself as a testimonial and say, “I used to believe that myself, too. I used to power through breaks, for whatever reason.” My view was that amateurs took breaks and professionals didn’t. That’s just diametrically, 100 percent erroneous. Professionals take breaks, amateurs don’t take breaks. I started thinking about breaks as part of my performance, not as a deviation from my performance, and you should, too. Don’t take it from me. Take it from this mountain of research showing that we’re more productive, more replenished, more creative, and happier, and we do better on our job if we take more breaks—and if we take these certain kinds of breaks.