Supine Leg Lift
Target Muscles: rectus abdominis
Set Up: Lie faceup on a mat, with your legs extended and raised a few inches from the floor. Place your hands behind your head and raise your shoulders from the ground.
Action: Slowly alternate lifting one leg until it points towards the ceiling, then the other. (Lifting each leg once counts as a single rep.) Remember to breathe and keep your shoulders lifted from the mat throughout your set.
-Oxygen Women's Fitness