Laying on your back, hands flat on the floor by your side and the ball on the floor in front of your bum
Grip the ball around the centre with the inside of your ankles
Slowly riase the ball away from you so that you are moving with your hips as well as your knees
Now slowly return the ball back to the starting position so the ball is just above your bum but not touching the floor
Repeat steps 3 and 4 until you can no longer maintain technique
Tips
The higher the ball is from the floor the easier it will be, so begin high and as you get stronger and more comfortable, lower the ball towards the floor
Be sure to keep your stomach muscles contracted throughout this exercise