Lie on your back with a your down by your sides and a yoga ball between your knees as shown. Place your tongue on the roof of your mouth and breathe through your nose. Draw your belly button in towards your spine. Crunch up towards your knees breathing out whilst your move.
Reverse the movement towards the floor breathing in as you move. This completes one repetition.
Keep your belly button drawn towards your spine to ensure you are protecting your spine during this exercise. Move slowly and controlled, do not use your momentum to get through the set, gently squeeze the yoga ball between your knees. Keep your tongue on the roof of your mouth, jaw relaxed, to take the pressure off your neck.