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.

Good news, slouchers.

It turns out mom was wrong. It's better for your back to slouch, rather than sit up straight.

Rodney Yee shares an exercise meant to open your hip joints and keep them mobile. You can take stress off of you knees and your lower back by working on the flexibility of your hips. It also elongates your spine and opens your chest!