Lie on your back with your knees bent and feet flat on the floor.
Bring your legs up to a table-top position, with your hips and knees at 90 degrees.
Cross your arms over your chest and tuck your chin to your chest.
Using your abdominal muscles, curl your upper body off the floor.
Control the movement back down, keeping your chin tucked in.
You may find it helps to push your tongue into the roof of your mouth.
Repeat this movement.