This exercise targets your abs and hip flexors.
Fasten an ankle strap around the bottom of each foot (with the ring on the bottom of your foot), and lie on your back. Move far enough away from the door so that the band is beginning to stretch. While keeping your legs straight, lift your feet about 6 inches off the floor. For stability place your hands on the floor.
hile balancing on your butt, pull both feet in, away from the door while you simultaneously raise your shoulders off the floor.
Try not to round your back as your raise your upper body. At the top of the movement your back should be straight and chest up.