Standing Rotations
Target Muscles: obliques
Set Up: Stand with your feet about shoulder-width apart. Place your hands lightly behind your head.
Action: Using your abs, not the momentum of your shoulders, and without pulling on your head or neck, rotate through your waist to the left, then the right. (One rotation to each side is one rep.) Your speed should be fairly quick but controlled, and keep your elbows in line with your ears as you move.
-Oxygen Women's Fitness