I've been reading an interesting article in the Harvard Business Review - an interview with David Allen and Tony Schwarz. One particular answer from Schwarz regarding work and energy struck me:
"There’s a fundamental misunderstanding about how human beings operate at their best. Most of us mistakenly assume we’re meant to run like computers—at high speeds, continuously, for long periods of time, running multiple programs simultaneously. It’s just not true. Human beings are designed to be rhythmic. The heart pulses; muscles contract and relax. We’re at our best when we’re moving rhythmically between spending energy and renewing it."
This is an interesting concept and one that I have noticed in my own work, but haven't applied the lesson as diligently as perhaps I should. It is very easy to fall into the busy trap and think that you can't afford the time to take a break. But I often feel more energised and productive after a break.
The habit of pushing your body, telling yourself to get on with it and keep going, is one that is hard to break. It is also something that is embedded in many work cultures - if you are not seen to be at your desk, you are not working hard enough.
One way of including breaks, but still accomplishing something, could be to run errands. I work on a fairly large site and delivering or collecting items from others allows me to take a break from my computer and still tick a job off my list.