Take position on the parallel bars of a dip machine. Your back is against the pad and your body hangs down freely. This is the starting position.
Commence the movement by contracting your abdominals and breathing out as you lift your legs up and to one side from their straightened position. Your legs are bent at the knee as you draw them up as high as they will go on that one side.
At the top of the movement, squeeze the abs hard before slowly lowering the legs back to the starting position, inhaling as you do.