The five-step high street routine

Step 2: The Bond Street bicep curl
Grasp the bags firmly at shoulder height and, breathing out slowly, straighten your legs until you are upright.

Step 3: Jiggle those Josephs
Breathing in, raise the bag in your left hand while lowering the one in your right, and hold for five seconds.

Step 4: Work those Whistles
Concentrate and repeat the movement in reverse. Don't worry, it's nearly over.

Step 5: Lie back and think of Selfridges
After such an exhausting workout, recline on the nearest sofa and attempt the shopper's lotus position.