The Oscar Arms Workout
'Arms are susceptible to "skinny fat", so even slender celebs have batwing moments,' says Fournier. 'The trick is to work all three muscle groups - biceps, triceps and deltoids.' How often? Do three sets of 12 repetitions, four days a week, for each of the following:

• Bicep Curl: Stand with feet shoulder-width apart, knees slightly bent and arms at your sides, holding 4kg dumb-bells, with palms facing forwards and elbows straight. Curl your arms up towards your shoulders, keeping your back straight. Slowly lower your arms to your sides.

• Tricep Dip: Sit on the floor with your back to a chair. Rest your hands behind you on the chair, with your fingers pointing forwards. Lift your buttocks off the ground and straighten your legs so only your heels are touching the floor. Bend your elbows to lower your buttocks towards the floor. Push back up until your elbows are straight.

• Deltoid Lift: Stand with your arms resting at your sides, holding 3kg dumbbells. Bend your torso forwards, keeping your back straight and your arms hanging in front of you. Raise both arms outwards to shoulder height. Lower both arms and repeat the lift.