article: 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 .
highlights: Sienna Miller, 33, is 'not a gym person' but loves yoga .
  Mother-of-one works with a personal trainer, power-walking and jogging .
  Try hip rolls, a Pilates move that targets the 'oblique' abdominal muscles .
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