Lay your belly on the ball and spread your legs wide and plant your toes on the floor.
Bend your elbows and gently touch your fingertips to the back of your head.
Take a breath in and, as you exhale, raise your upper torso as much as you can, so your chest comes off the ball. Inhale to slowly lower your torso back to the starting position. Keeping your movements slow allows you to work your abs.