It was about three years ago, while running a studio in Los Angeles, that Ms. Anderson came to the attention of Ms. Paltrow, who then told her friend Madonna. Now the bulk of Ms. Anderson’s time is devoted to the two stars: she essentially moves in with one, depending on whose career is in higher gear, while working with the other through video chats and custom DVDs, or by dispatching one of her associate trainers.

When Madonna was preparing for her “Sticky and Sweet” tour last year, for example, Ms. Anderson lived with her for nine months and then accompanied her on the road. Last summer, she trained Madonna during the day in Manhattan and took the train almost every day to the Hamptons to put Ms. Paltrow through a workout in the evening.

“Tracy Anderson is my savior,” Madonna said in an e-mail message. “After two Caesareans, three hernia operations and one riding accident that left me with 10 broken bones, she was the only one who could pull my body back together into one piece.”

Source: NY Times