Braganza met with each of the actors for one-on-one sessions in a fully-equipped on-set gym trailer over the five months of filming.
“Dakota used the trailer almost every day when she was on set, I would say five days a week,” Braganza tells PEOPLE. “Sometimes she would do a full program, and sometimes she would just do 20 minutes of cardio.”
A typical workout for Johnson, 27, focused on her legs, abs and arms.
“She came already fairly lean, so she wanted to get toned,” says Braganza. “We did a lot of dance-type stretching to music, then we would do a circuit with some leg work. One of the things she really enjoyed doing was lying on the floor doing old-school Jane Fonda-type leg raises, and I included some leg weights to bring the intensity up. That was effective for her legs and glutes.”
Braganza put Johnson through her 3-2-1 program, which includes three bursts of cardio interspersed with two circuits of three moves each, and one section of ab exercises.
“[For cardio], she would run on the treadmill on an incline because that works your glutes a little bit better, and jump rope,” says Braganza, who also trains Bull series star Michael Weatherly. “The circuits used low body weight and a lot of stretching.”
Johnson supplemented her workouts with Braganza with hot yoga classes.
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For Dornan, 34, Braganza made sure to balance out the upper-body workouts he did on his own with leg-focused training sessions one or two times a week.
“If you train your legs, you actually increase your metabolism and it can grow muscles all over the body,” explains Braganza. “If you ignore your legs, it defeats the purpose of strength training because legs are a big powerhouse of the body.”
A session with Dornan would typically include five to 10 minutes of leg stretches followed by a jump rope warm-up. To put on muscle mass, Dornan would do squats with heavy weights, as well as lunges and deadlifts.
“He’s very focused and very serious about his workouts,” says Braganza.
In addition to being disciplined about their workouts, both Dornan and Johnson made sure to stick to a healthy diet while filming Fifty Shades Darker.
“They put in a lot of effort, and they ate really well as well,” says Braganza. “That makes a difference in how you end up looking on camera.”