Getting ready to work with Tom Cruise in the latest installment of “Mission: Impossible” can be a daunting task. That’s where trainer Sam Eastwood steps in.

Eastwood was brought in to get star Rebecca Ferguson into fighting shape for “Mission: Impossible-Rogue Nation” six weeks before the film began shooting. The workouts were intense: six hours a day, six days a week.

Once Ferguson saw how her body was reacting to training, Eastwood stayed on for the entire production where they trained in one-to-three-hour increments, depending on the daily shooting schedule.

Action-star ready

In this exclusive interview, Lifescript spoke with Sam Eastwood about what it takes to become an action star.

Eastwood found it easy to start a training regimen with Ferguson because she was fit, but there were adjustments to be made.

“She came from a dancing background. Rebecca had been playing lots of princesses where her posture very upright,” says Eastwood. “So we had to work on alignment stuff with her. I brought her posture back to a neutral stance.”

In order to get her into a more aligned state, Eastwood used a series of exercises to achieve a “feminine, yet strong” look. Ferguson incorporated running, yoga, stretching and Pilates into her daily routine.

“With any Tom Cruise movie, Tom sets the standard. Rebecca was 100% committed to that. She had to be strong and she had to be able to fight for 10 minutes and go at it again and again and again,” explains Eastwood. “Rebecca had to be tough and as strong as Tom Cruise but still have a long, lean, muscle-toned body.

Read “Best Strength-Training Exercises for Women” on Lifescript.com

In order to make sure the actress was prepared for each scene, Eastwood worked closely with stunt coordinator and husband, Wade Eastwood.

“I would watch whatever Rebecca was doing on set,” she says. “We would work on her movements and then incorporate it into the workout.”

Targeting the right muscles

Some of the areas they targeted during her on-set workouts included lats, obliques, quads and hamstrings. “It was simple, but technical stuff because Rebecca’s body was under a lot of stress,” says the trainer.

[Editor’s Note: The latissimus dorsi muscle [“lats”] is one of the largest muscles in the back. The muscle is located in the middle of the back. The abdominal external oblique muscles are the largest and the outermost of the three flat muscles of the lateral abdomen.]

When it came to diet, Ferguson was already a clean eater, so they didn’t have to adjust her food intake.

“She made good choices with her food,” she shares. “As the old saying goes, ‘you are what you eat’ and she was super sensible with her diet.”

Rebecca Ferguson plays Ilsa in ‘Mission: Impossible.’
Photo credit: Keith Hamshere/Paramount Pictures

The hard work Ferguson put in before and during the shoot is evident in a pinnacle action scene. Her shapely legs are on full display while dressed in an evening gown with a sky-high slit — fitness never looked so sexy.

“To achieve that look, we leaned out the muscles and made them long with reps of planks. We did a lot of ballet-based movements and we stretched after running,” says Eastwood. “I love to incorporate ballet because it is good for thighs and calves.”

Rebecca Ferguson plays Ilsa and Tom Cruise plays Ethan Hunt in ‘Mission: Impossible.’
Photo credit: David James

The fitness trainer also offered Lifescript a few tips to achieving an action-star physique:

• “Live Life From The Core”-It’s important to have your abdominal core in shape, so a Pilates workout is a great way to strengthen those muscles.
• High Reps, Low Weights– Do a repetitive series of movements using body weight instead of heavy weights. 
• Run and Stretch-Strap on those jogging shoes and do some low-level running to lengthen those leg muscles. Don’t forget to incorporate stretching before and after your workout.

“Mission:Impossible-Rogue Nation” opens nationwide on July 31.