Hilary Swank shows off a chiseled back as a boxer in "Million Dollar Baby" (opens tomorrow). Jennifer Garner sports tightly toned abs as an action hero in "Elektra." Jessica Biel has deltoids to die for in "Blade: Trinity."

But sometimes public sentiment on that runs along the lines of: "If I had a trainer and chef, I'd be in the best shape of my life too."

Not so fast, say fitness consultants to these stars. It's true that celebrities enjoy perks such as private training and nutritionists, and have plenty of time and motivation — such as big paychecks and costumes that leave nothing to the imagination. But the Laws of Physiques aren't suspended for the rich and famous.

Biel, Swank and Garner earned their bodies the old-fashioned way: eating right and exercising.

Cardio and weight workouts were central to all three actresses' regimens.

As for diet, all three women ate three moderately sized meals and two or three snacks a day, kept a close eye on portion sizes and drank plenty of water.

Having a trainer at your side is nice, said fitness consultant Bobby Strom, who helped whip Biel into shape for "Blade," but "I can't get on the machine and work out for Jessie. I can push, but she has to do it. She has to make the commitment. She has to choose what she's going to put on her plate."

There's nothing easy — or particularly mysterious — about getting in shape, whether you are a celebrity or not. And you don't necessarily have to spend as much time in the gym as the stars, trainers said. An hour's time, five to six days a week, will make a difference.

The fitness experts say they are hoping that 2005 will bring a more moderate approach to diets and exercise — and perhaps a definition of beauty:

"They're strong, but they're still feminine," said Strom.

With the "Blade" shoot behind her, Biel, 22, still makes exercise a priority. Now, though, she ratchets up the intensity and incorporates weight workouts — "I like the muscles."

Swank, 30, walked into the gym model thin, and struggling to keep weight on as she spent hours each week in a ring with boxing coach Hector Roca, preparing for her role in "Million Dollar Baby." Shooting was just nine weeks away.

"There wasn't a moment to lose," said Grant Roberts, who was hired to focus on Swank's nutrition and weight training.

Swank said the biggest change was not in her body, but in her mind. She'd fire herself up with an internal pep talk while she imagined the fearsome boxer she wanted to look like.

"I'd be lying in bed, thinking, 'I don't want to do this, I don't want to get up' and then I'd start telling myself: 'If you want to grow, you've gotta get up. ... You've got here to get in shape and change your body,' and I'd really, really think about what I wanted to look like," she said. "By then, I'd jump out of bed."

By the time the cameras began rolling, Swank had gained 20 pounds, nearly all of it hard muscle.

When Garner was shooting "Elektra," she had to be ready for hair and makeup by 5:30 a.m. Filming was unpredictable, and often went far into the night, so night workouts weren't an option.