This exercise is used to strengthen and shape the lower abdominal region.
Begin by lying on the floor with your lower back pressed against the floor. Extend your arms to each of your sides with your palms facing down. Your legs should be extended in front of you with a slight bend in your knees. Now, lift your heels off of the floor approximately 6 inches. Now, lift your right leg up until it creates a 45 degree angle with the floor and then bring it back down until it is only 2 inches from the floor. Now, switch legs and repeat the movement with your left leg. Continue this movement with each leg until your set is complete.
Make sure to breathe while you do this exercise. Also, do not allow your heels to hit the ground, keep constant pressure on your abs.
Press your lower back into the mat, if your back begins to arch and can put a lot of stress on your lower back. Also, it will take the pressure off of your ab muscles.