Halle Berry needed a superhero body to be ready to film Catwoman. Where did she turn to get in shape?

Halle Berry called fitness trainer and founder of 5-Factor Fitness, Harley Pasternak. The two are currently working toward getting her back into superhero form for the new X-Men 3 movie.

Harley Pasternak is the first to admit that Halle Berry isn't a big fan of working out. "Halle Berry is amazing," he says. "She's naturally pretty athletic, having been a gymnast when she was younger. She does not like to exercise, but she definitely knows she needs to, and it's a means to an end."

Pasternak says for Halle Berry it's all about the end product. "She has no problem working her butt off as long as she doesn't have to do it for too long, and as long as she sees results."

To keep Halle Berry happy and motivated, Pasternak keeps her workouts short, intense and effective. And even though she always stays on 5-Factor to some extent, Harley Pasternak says her routine changes depending on which movie she's working on at the time.

"The 5-Factor Fitness plan," he says, "is the product of several years of being a science nerd, a fitness nut and an exercise and nutrition scientist for the military, and then having the opportunity to work with a lot of actors who have very little time and have to see results."

The workout component of 5-Factor is based on five, five-minute phases:

• Phase 1: Cardio warm-up
• Phase 2: Upper-body strength exercise
• Phase 3: Lower-body strength exercise
• Phase 4: Core (midsection) exercise
• Phase 5: Fat-burning cardio

The nutrition portion of 5-Factor is just as simple as the fitness routine, Harley Pasternak says. Eating five meals a day is optimal for keeping your blood sugar stable and metabolism in check. Each meal should fulfill these five criteria:

1. The main dish should be a low-fat, quality protein.
2. It should include a low-to-moderate glycemic carbohydrate (think beans, vegetables, sweet potatoes, wild rice).
3. You should have five to ten grams of fiber per meal.
4. Only healthy fat should be added to the meal.
5. Always include a non-sugared beverage.

Harley Pasternak has created more than 100 recipes, all of which take no longer than five minutes to prepare, and most use no more than five common ingredients.

Although Harley Pasternak advises eating more even when many other diets out there support consuming less, Harley Pasternak says the program is successful because it's a lifestyle. "I think the eating component is the most important part of the program," he says, "because it's a voice of moderation in a time where every diet out there is very extreme and not sustainable. So you don't have to cut your carbs. You don't have to weigh your food. These are all unnatural acts that cannot be sustained year in and year out. They're not fun, and they're difficult."

Sometimes Halle Berry will be training five days a week for 30 minutes a day, and other times she'll cut it down to three times a week.

"In Catwoman there was a special need for her to be ultra-fit and very lean and very strong," he says. "And in Our Eyes Are Watching God, we had to kind of let it go. You know, really had to let her be less toned and a little looser."

Harley Pasternak says she sticks with the nutrition aspect of 5-Factor. And even though she might be used to playing larger-than-life roles onscreen, Halle needs her "cheat" day just as much as the rest of us.

Harley Pasternak wouldn't tell us her weakness, but he admits, "Let's just say Halle Berry enjoys her cheat day."