Fot the Windshield Wipers, perform a 180 Leg Raise so that your feet are vertical against the bar. Next, while holding this position, rotate your torso to one side until your legs are perpendicular to the floor. Once at the end range on one side, rotate the torso past center and completely to the opposite side. Repeat this motion at a consistent pace to perform the exercise, mimicking a windshield wiper.
Muscle groups involved: Abs, Obliques, Hip Flexors.