Natalie Portman writes foreword for ballet book

Natalie Portman has repaid the ballerina who trained her for Black Swan by writing the foreword to her new fitness book.

The Hollywood actress won an Oscar for her performance as a troubled prima ballerina in the 2010 movie and she credits her trainer, Mary Helen Bowers, with getting her into shape and helping her learn complicated dance moves.

Bowers has now written Ballet Beautiful to help others gain the grace of a ballerina and Portman has written a tribute to her friend in the book.

She writes, "My posture looked like I'd swallowed a broom... I had the same body since (I was) 14. With Mary Helen, it's completely transformed. I gained length, strength and tone. Arms and legs changed shape. In awe of dancers' bodies - definition in their arms, strong legs and beautiful line extending from fingertips to toes... (plus her) healthy diet in conjunction with the exercises achieved our fitness goals."