Well guess what? It's time to start taking these breaks, even if it's for only 5 minutes.
We don't take cigarette breaks anymore, since most people I know have quit smoking. We don't NEED that extra cup of coffee, and if you do, that's something you might want to contemplate on a deeper level...but that's beside the point.
I challenge you to take a 5 minute break with your eyes closed in a comfortable seated position. If it is impossible for you to do this at work because you work on your feet or you don't really have your own space to carry out this challenge in relative peace, you have no excuse. Most work places have bathrooms with stalls. Take a nice 5 minute crap break without actually taking a crap. If you're totally grossed out by this prospect, see if you can find another secluded place where you won't be interrupted.
I find that it helps to have some music to listen to also. This is also a nice time keeper so you'll be sure to sit for more than just 1 minute. Get your ear buds, play a song that you absolutely LOVE from beginning to end and really listen to it.
I guarantee after you do this you'll be fresher and ready to face the task at hand.
I personally try to do this twice a day. Sometimes it's hard to drop what I'm doing, but nine times out of ten, when I come back to it, I notice something that I missed before.