Robert Pozen

It's 5 P.M. at the office. Working fast, you've finished your tasks for the day and want to go home. But none of your colleagues have left yet, so you stay another hour or two, surfing the Web and reading your e-mails again, so you don't come off as a slacker. It's an unfortunate reality that efficiency often goes unrewarded in the workplace.

Everyone knows that exercise can improve your health. Exercise is a key part of managing your weight and maintaining healthy hearts, lungs, and other bodily systems. But did you know that exercise can make you more productive? The latest research shows that a regular exercise routine can make you happier, smarter, and more energetic.