Your abs and obliques may not like it but they will thank you for making them stronger with this exercise.
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. When curling up, twist so that one elbow is pointing at your knees. Hold the curled position and contract the abdominal muscles for 2 seconds. Repeat to the other side.