Cross Crunches

Lay flat on your back with your feet flat on the ground

Now place your hands lightly on either side of your head keeping your elbows in

While pushing the small of your back down in the floor to better isolate your abdominal muscles, begin to roll your shoulders off the floor

Raise your shoulders such that you try and touch yout left knee with righ elbow

Hold for a second and then lower back to the starting position

Raise your shoulders again and touch your right knee with left elbow

Hold for a second and then lower back to the starting position