The Five Rules of Flat Abs

Rule #1

Attack your hidden core muscles
Crunches target only superficial muscles, so they aren’t the most efficient way to work your abs. Hard fact: To burn one pound of fat, you have to do 250,000 crunches, according to researchers at the University of Virginia. That’s 100 crunches a day for seven years. Uh, no thanks.

Instead, you need to target the muscles that lie beneath the superficial ones: your transverse abdominis, multifidis, and internal obliques. Strengthening them pulls in your middle like a corset, keeping the area looking flat and toned. “Not only are these muscles weak in many women, but most of us don’t have a clue about how to engage them,” says celebrity trainer Valerie Waters, whose clients include Jennifer Garner and Elizabeth Berkley.

The core moves here target these “hidden” muscles. To practice engaging them, try this drill from Waters: Lie on your back and place your palms just below your navel. Exhale and allow your tummy to expand as far as you can, then focus on pulling your belly button toward your spine, drawing your abdomen toward the floor. Hold for 5 seconds. Repeat 8 to 10 times.

Join us next week for Rule #2