What has a bum knee taught me?

It can be a welcome excuse to blow off any exercise I don't like, and an annoyance to endure for a sport that I love.

Personal trainer Matan Gavish stresses that balance is the key to achieving one's fitness goals, so he named his New York-based business Diet & Exercise to emphasize that it's a complete program. But his passion for balance might also explain the apparent split-personality vocation -- he's equally adept at training Special Ops soldiers as he is helping brides-to-be tone their "strapless muscles" and drop dress sizes.