This exercise can be quite difficult for beginners to get use to. But I highly recommend it as it will help build your body's core stabilising muscles.

 

To perform swiss ball leg raises lay down on the swiss ball with your back in the centre of the ball. You will need something to hold on to - in the video I am grabbing onto the smith machine. Anything stable and stationary will do. From this position lift your head and shoulders slightly up in the air. With your knees slightly bent raise your legs off the floor making sure to keep the tension on your lower abs. Try not to lift your legs too high as to not release the tension from your abs. Lower your legs down slowly in a controlled manner. Do not place your feet on the floor, keep them above the ground. Repeat the process.