Crunch

Lie on your back. Bend your knees and place your feet about a foot from your glutes.
Place your hands on the back of your head so that your thumbs are behind your ears. Drop your chin down toward your chest but not touching it.
Pull with your core muscles while simultaneously lifting your head, neck, and shoulder blades off the floor. Pause for a one count.
Slowly lower back down to complete one repetition.
Repeat for one minute.