Get lardy Darcy back in shape Actor Colin Firth has turned to the fitness instructor who restored Leonardo DiCaprio's lean physique after the Titanic star's eating and drinking binges turned him into a flabby weakling. Firth, who won an army of female fans as Mr Darcy in the BBC adaptation of Pride and Prejudice, was put through a punishing three-month fitness regime for his sexy new screen role in Bridget Jones's Diary. The producers, fearing that he was overweight, had ordered him to get in shape for the film of Helen Fielding's best-seller. It was crucial that Firth, 39, was in prime condition, because he was the man Ms Fielding had in mind when she created her brooding hero Mark Darcy—the character he plays as part of the author's in-joke. Ironically, as Firth has been fighting the flab, his co-star, Hollywood actress Renée Zellweger, has been trying to pile on the pounds. She plays fictional thirtysomething Bridget, who is obsessed with her weight. Slim Renée has been eating pizza and hamburgers so she can be more convincing in the role. Firth gave up alcohol and fried food to achieve the lean look he needed. One-to-one instructor Cornel Chin, who whipped DiCaprio into shape for The Beach, said Firth was one of the most dedicated stars he has worked with.

"They called me in a couple of weeks before filming started, so it was a bit of a rush job," he said. "Colin wanted to  meet a target in a short time so we had to work incredibly hard. We blitzed his whole body. He is one of the most       hard-working clients I've had."

The star is so impressed with his athletic new look he has vowed to stick to the strict fitness routine. He said: "I definitely needed to get in shape for the film. In this day and age you need to be in trim if you are going to be a top actor. But I wanted to get in shape regardless of the film, and this is going to be a lifelong commitment. To get fit for the role was a bonus, but I intend to stay in shape for life now."

Cornel put Firth through his paces in a daily hour-and-a-half workout aimed at turning flab into an impressive layer of muscle. The routine, at the actor's north London home, started with a 15-minute warm-up jog followed by aerobics. 

Firth built a muscular physique with an intensive weight-training programme and press-ups, and developed a six-pack stomach with 400 sit-ups a day. He lost a stone in weight with a diet of pasta, poultry, fish, cereal, rice, milk and water.

Cornel, 30, added: "Colin has done exceptionally well. There's a distinct difference and I don't think his female fans are going to be disappointed. Now he is in really good shape. He is a lot leaner than he was as Mr Darcy, when he  was fairly podgy. He has lost a lot of weight and it shows. He has made a complete lifestyle change.

"The first thing I told him was to cut out alcohol. He wasn't a massive drinker before, but he did not drink at all for  two-and-a-half months and now he drinks a lot less than he used to."

Cornel went on: "He has also changed his diet and is going to keep exercising. He wants to see me at least once a fortnight to keep a check on him. He's such a genuine person I believe him."

Cornel, from Bromley, Kent, was a little-known gym instructor when he landed the job of improving DiCaprio's  physique for The Beach. The young star had allowed a party lifestyle and the perks of fame to take their toll on his     looks, and Cornel helped him shed nearly 2st in two weeks with a two-hour exercise programme twice a day.