You'll look like tassels in the wind while doing this exercise, but it's one hell of a workout! Though it seems ridiculously easy, you'll see just how hard it is once you assume the position. Your forearms get an awesome workout gripping the bar, but it's your abs and back that are hit hardest. Just the fact that you're holding your body parallel to the floor is hard enough, but adding the leg flutter makes it the workout of a champion!
Hannibal for King Leg FluttersGrip a pull-up bar in the Chin-Up position (palms facing you). Raise your legs until your body is parallel to the ground. Tighten your core to keep your body in that position, and flutter your legs up and down as you hold yourself. Watch the video to see how it's done: When finished, lower yourself slowly--focusing on the eccentric phase of the movement.
Hard work in the kitchen + Hard work in the gym = Abs!