If you’ve ever tried to kneel on one, you’ll know that Swiss balls are unstable. Exercising on one requires a mixture of determination, co-ordination and strength. Combine this with a pair of dumb-bells and your body has a calorie-crunching challenge on its hands.

But it’s not just your waistline that’ll be feeling the pressure. Because you’ll be spending much of this circuit stabilising the dumb-bells on the wobbling platform of the Swiss ball, you’ll be hitting the smaller, stabilising muscles that keep your joints in line and free from injury. Stronger stabilisers mean that you can go heavier on your weight training days and get bigger muscles faster without busting any ligaments.

How to do this workout
All you need for this workout is a pair of light dumb-bells and a Swiss ball. These are available from http://www.goldsgymdirect.co.uk and www.reebokfitness.co.uk. Perform the exercises in order, taking no rest in between. Once you’ve completed one circuit, rest for two to three minutes before going again. You sould complete at least two circuits, but regular exercisers can attempt four or more. Do the circuit three times a week for four weeks, leaving at least one day between workouts.