Begin with your knees on the floor and your upper body resting on the fitball, hands joined together and rest your chin on them keep your elbows by your side
Now lift your knees off the floor so your body is in a straight line from heels to shoulders
Now lift your chest off the ball and ensure you contract your stomach muscles and hold them tight, dont forget to breathe
Hold this position for as long as you can manage
Relax gently when you can no longer contract your stomach muscles
Tips
For this exercise to be effective, ensure you contract your stomach muscles throughout the duration of the exercise