Start: Warm up with five minutes of gentle cardio to get your muscles limbered up and ready for action.

Lie on your back holding a dumb-bell in each hand by the sides of your chest. Place the backs of your ankles on the Swiss ball and lift your hips, lower and mid-back off the floor so your body is in a straight line from ankle to neck. Press the dumb-bells straight up above your chest, keeping the ball as still as possible. Lower them slowly and repeat.