What to do

TO WHIP your waist into bikini shape, get ready to do the hula, says personal trainer Nadya Fairweather ( u-shape.co.uk).

Place a stability ball on a non-slip mat. Sit on it with your feet apart, relax your shoulders and sit tall.

Shift your hips, side to side, 50 times, then circle hips as if hula hooping 50 times. Rotate other way for 50 more. Tilt hips forward and back for 50 reps. Repeat routine. This is great for working the core. It also uses muscles in your back — and improves posture.