Lay flat on the floor with your feet flat on the ground and knees at a 90 degree angle.
Place your hands behind your head or across your chest. Beginners should place them across the chest.
Curl your torso towards your knees, lifting the shoulder blades off the ground.
Hold the curled position and contract the abdominal muscles for 2 seconds, then slowly return to the starting position.
If your hands are behind the head, they are only there to make the exercise harder, and not to help you pull your head up. Using force to help lift your head up may cause injuries.