We reveal how to get the enviable physiques of the stars . This week : Sienna Miller 's waist . Judging by her tiny waist , Sienna Miller works at maintaining her shape . Sienna Miller s a yoga fan - her mother started one of the first London yoga schools in the Seventies . Yet despite being 'very sporty at school ' , the actress says she 's 'not a gym person ' . But the mother-of-one is a yoga fan - her mother started one of the first London yoga schools in the Seventies . Sienna also works with a personal trainer , power-walking and jogging around her local park and using light weights to tone muscles . What to try : . Hip rolls , a Pilates move that targets the 'oblique ' abdominal muscles around the waist . Lie on your back , knees bent and feet flat on floor , hip-width apart . Take arms out to sides at shoulder height , palms facing upwards . Slowly roll knees to right side , taking head gently to the left . Turn left palm down , keeping shoulder blade anchored to the floor . Engage abdominal muscles and return knees to the centre . Turn your palm back up and repeat on the other side . Do this ten times . The slim actress also works with a personal trainer , power-walking and jogging around her local park .
Sienna Miller , 33 , is 'not a gym person ' but loves yoga . The actress has been seen in the past wearing black and white workout clothes with her hair pulled back into a ponytail while she works out at home on an elliptical machine. Try hip rolls , a Pilates move that targets the 'oblique ' abdominal muscles .