Crunches are not enough: These six moves -- three that strengthen your insides, three that target your outer abs -- keep you looking and feeling beautifully balanced.
What It Does Helps you use your abs in concert (unlike crunches, which isolate one muscle group)
How to Do It Lie on your back with your arms in the shape of a T and legs lifted so they're perpendicular to the floor. Shift hips a few inches to the left, then exhale and drop both legs slowly to the right, stopping before they touch the floor. Hold for a deep breath, exhale, and return to the starting position. Repeat on the other side. Alternate for 20 reps, 10 on each side.