In the wise words of Dolly Parton, "Working nine to five ... it's enough to drive you crazy if you let it." If you want to avoid the driving-you-crazy part and be more productive and less stressed, the answer is simple: Exercise.

University of Bristol researchers found that people who exercised on work days -- either before work or during lunch -- experienced less stress and were better able to handle the challenges of their workdays.

It's not surprising, really. Exercise can do wonders for your mood. And if you have a crabby co-worker, a demanding boss or unreasonable deadlines to deal with, you can certainly use a little boost in the mood department. And physical activity can increase your energy which, in turn, will make you a more productive employee. So get moving! You never know ... maybe your boss will notice your great performance and you'll get that raise you sorely deserve.