Exercise 4: Knee-In
Primary Target: Lower Abs
Sit on the floor (or on the edge of a chair or exercise bench) with your legs extended in front of you and your hands holding on to the sides for support.
Keeping your knees together, pull your knees in towards your chest until you can go no farther.
Keeping the tension on your lower ab muscles, return to the start position and repeat the movement until you have completed your set.