LONDON: Drew Barrymore chose a real balancing act for her directing debut. She does it on wheels, directing and acting alongside Juno star Ellen Page in Whip It - a rowdy tale of roller-derby.

Barrymore, who had never put on skates before shooting the movie, spent a month alongside cast mates learning the ropes in a roller-derby boot camp.

Her training as a director has been going on for years, since she began producing movies in the 1990s; her credits including her Charlie's Angels adventures and her Adam Sandler romance, 50 First Dates.

Once they acquired the rights to roller-derby player Shauna Cross's book, Whip It, Barrymore and production partner Nancy Juvonen began casting about for a director. Before long, Barrymore realised that this was the one she had to direct herself.

"I've been producing for 15 years and it's all been preparing for the big test. I really care so much about what I do - and I love film-making so much. I love every detail and every aspect of it," said Barrymore, 34, in an interview at the Toronto International Film Festival, where Whip It premiered in advance of its release in cinemas.

"I think slow and steady wins the race, too.”

"I didn't need to direct when I was 21. I wanted to produce and learn about the film-making process and understand every element going into it, so that by the time I did direct, I was as knowledgeable and well-prepared as possible."

Whip It stars Ellen Page as Texan teen Bliss Cavendar, who follows the path of her mum (Marcia Gay Harden), a former beauty queen overseeing her daughter's rise on thepageant circuit.

On a whim, Bliss tries out for a cellar-dweller roller-derby team, discovering that she's a natural skater and soon leading her squad on an underdog quest for the local league championship. Kristen Wiig, singer Eve, stuntwoman Zoe Bell and Barrymore co-star as some of Page's team-mates, with Juliette Lewis as her nemesis, the star of the league's top team.

Barrymore proudly points out that she cast Page before production began on Juno, the 2007 Toronto festival hit that shot her to stardom, became a $100 million smash and earned her a best-actress Academy Award nomination.

Page, 22, said she has looked up to Barrymore since her early teens, admiring her for the strong women she has presented on screen, both as an actor and as a producer.

"She's maintained such a sense of identity: she's never let herself be pigeon-holed, she's never worried about what people think," Page said.

"Every single person has wanted a piece of her, her whole life, yet she still maintains this groundedness and kindness that is really remarkable."

A scion of one of Hollywood's great acting dynasties, which includes her grandfather John Barrymore, Barrymore has been a star since early childhood when she debuted in the sci-fi tale, Altered States, and later became a screen darling in the blockbuster, ET the Extra-Terrestrial.

Twice-divorced, she's currently in an on/off relationship with Justin Long, her co-star in He's Just Not That Into You.

While Barrymore was not necessarily looking to act in her own directing debut, she took on a supporting role so that she could bond with her cast as they tripped and stumbled through their derby training.

"It was one more thing on my plate that I kind of didn't need, as a director, because you've got so much going on - the training and the derby and skating on wheels and directing, on top of all of that,''Barrymore said.

"But I thought it was invaluable to the process, as far as creating that trust and relationship and chemistry with all the girls."