How 7 different actors' workout routines got them ready for intense movie and TV roles

• In this episode of "Movies Insider," we look at how seven actors prepared for challenging and physical roles, according to their trainers.
• From Michael B. Jordan getting jacked for "Black Panther" to Jennifer Lopez learning to pole dance for "Hustlers," find out how specialized workout regimens get actors physically ready to play iconic characters in movies and TV.

Following is a transcript of the video:

Narrator: There are more than 600 muscles in the human body. But if you're training for a main role on "Riverdale," only a small fraction of those really matter: the chest, shoulders, and abdominal V cut, which stars like KJ Apa sculpt to look great on camera.

Every role has its physical demands, whether it's all about aesthetics, acrobatics, size, or strength. Let's take a look at the highly customized training programs of seven actors preparing for intensely physical roles.

Michael B. Jordan is pretty much always in great shape, but the body he sculpts in training depends on the character he's getting ready to play.

The actor was fresh off his role as Adonis in "Creed" when he started gearing up to play Killmonger in "Black Panther." Both are very physical roles, but they're also very different. One is a boxing hero, the other a supervillain. Plus, Killmonger was Michael's first time playing a bad guy, so he had to do everything he could to get in the character's head -- and body.

Michael's longtime trainer, Corey Calliet, said all these factors helped shape his client's regimen. For Michael to play Adonis, Corey said the goal was to get "lean, lean, lean." The program involved a lot of running and, surprise, boxing.

But while the actor's "Creed" training was all about getting cut, his "Black Panther" training was all about getting big. Michael and Corey wanted to build a body that would surprise people. So, using the foundation he'd built for "Creed," Michael ditched his high-cardio routine for intense weight training built around curls, squats, and bench presses.

Corey is also Michael's nutritionist. And for "Black Panther," he had his client eating five to six meals a day on a carb-heavy diet that included lots of potatoes, eggs, bacon, and chicken. This helped Michael fill out his upper body and ultimately add 15 pounds of muscle to his frame.

But right after "Black Panther," he headed back into the ring for "Creed II," which meant he and Corey had to bring back Adonis all over again.

Each Avenger has their own set of skills. Natasha Romanoff's are her martial arts. When Scarlett Johansson landed the role in 2009, she enlisted celebrity trainer Eric Johnson to turn her into the deadly assassin we see in the "Avengers" movies. The first part of Scarlett's training was all about mobility.

Many of Black Widow's signature moves are spider-inspired, like this leg-twist attack, where she wraps her leg around the neck of her opponent. That's a pretty high kick, Eric says, and it requires a lot of hip mobility and hip-flexor strength. He had Scarlett do 90-90 hip swivels so she could perform the move explosively.

The second stage of her training was aimed at building power. Eric had Scarlett doing a 245-pound deadlift and single-leg pistol squats in this phase of the training. That power translates on-screen in Black Widow's kicks and punches, like here in this scene from "Captain America: Civil War." A lot of people think punches only come from the arms or the upper body. But Eric says that if you want to produce power, "it has to come from the ground all the way up to that fist."

The third and final phase was geared toward getting Scarlett at peak conditioning level. This phase refined some aesthetic aspects of Scarlett's performance. For one, Eric had Scarlett practice her recovery after an intense set, gaining control of her breathing and getting her heart rate down as fast as possible, so that she could better control her face on camera. After all, she couldn't afford to have a pain face on when playing Black Widow. She needed to look as poised and controlled as a superhero would.

If Black Widow's strength lies in her punches and kicks, Spider-Man's lies in his agility and acrobatics. Luckily, Tom Holland has a background as a dancer and gymnast.

Tom said he had to audition eight times to play Spider-Man and his athleticism ultimately helped land him the role. Even with a solid foundation, though, Tom had to train hard in preparation for his first solo Marvel film, "Spider-Man: Homecoming." After all, his acrobatics had to look superhuman, which meant convincingly climbing walls, doing wild flips, and slinging webs through the city. Here, Tom's following his stunt double, Holland Diaz, in doing a side somersault off a mini trampoline followed by a big kick out and a perfect left-foot landing.

When he wasn't in the gymnasium, Tom kept his training up with an AirTrack mat, a giant inflatable and portable piece of equipment that's kind of like a spring floor, bouncy castle, and tumbling and landing mat all wrapped up into one. He used this to practice his twists, flips, and side somersaults.

Tom was determined to do most of his own stunts, but he had to do CrossFit-style circuit workouts to make sure he could work day in and day out on set. To sharpen his Spidey reflexes, Tom went through extensive martial arts and combat training. Here he is again with his stunt double working on his hand-eye coordination.

And then there was the question of aesthetics -- filling out the Spidey suit and looking good out of the suit too. One of Tom's trainers, George Ashwell, said the shirtless scene in the script motivated Tom to add 14 pounds of muscle to his frame. The actor did sets of chin-ups to build up his chest. Tom shared this photo with Marvel trainer Duffy Gaver on their last workout day, showing off his body in peak Spidey shape.

"Riverdale" has been known for its shirtless scenes from the beginning, but season three brought a new challenge for star KJ Apa, whose character, Archie, goes from high-school football jock to prison boxer. Given the number of bare-chested fight scenes he'd have to appear in, KJ decided to step up his fitness routine under the guidance of Alex Fine, the "Riverdale" cast's secret weapon.

After getting his start doing strength conditioning for NFL stars like Odell Beckham Jr., Reggie Bush, and Marshawn Lynch, Alex went on to train KJ, Charles Melton, Cole Sprouse, Camila Mendes, Casey Cott, Hart Denton, and Mark Consuelos. Actors are different from athletes, he says.

For guys like KJ or Charles, who plays Reggie on the show, Alex will pay special attention to the top of the chest and shoulders, since those areas are the most noticeable on camera.

For season three, Alex incorporated high-intensity cardio into KJ's weight training to help him get a lean waist. He had KJ doing two 90-minute workouts a day. Often they'd tackle cardio in the morning and then do weights in the afternoon. Beyond basic weightlifting, Alex has clients like KJ do a lot of body-weight exercises, including sit-ups, planks, push-ups, pull-ups, and chin holds.

This regimen has the advantage of using minimal gym equipment -- "basically a prison-cell workout," Alex says. Creating a bigger chest and leaner waist gets clients like KJ closer to one of the aesthetic goals for "Riverdale" stars: sculpting that V cut, also known as the "sex lines." That's the deep V-shaped cut where the lower abs and obliques meet. This is one role where vanity muscles maybe are the most important thing.

Bob Odenkirk was a comedy writer for 25 years before starring as TV's favorite lawyer, a decidedly nonaction role. But at age 58, he starred in his first-ever action movie, "Nobody." Bob got a head start on bringing out the fighter within. He started training for "Nobody" before the film was even green-lit. It's standard for an actor to train for four to six weeks for a role; Bob trained for two years.

As a guy in his 50s, Bob wanted to avoid getting sidelined by an injury. For that reason, his trainer, stunt actor Daniel Bernhardt, said that intense weight training, like lifting a heavy bench press, "was not on the table." Instead, Bob's training "was all about movement." Daniel gave him a crash course in screen fighting based on the concept of hip rotation.

According to Daniel, fighting is all about "how you turn your hips when you throw a punch, when you take a reaction."

For Bob, learning to activate his hips helped blast his core and provide him with the explosive punch power he needed for the bus fight in "Nobody." Director Ilya Naishuller wanted Bob to fight like a wolverine in that scene. The goal was for him to pull off 99% of his own stunts, so they wouldn't have to use fast-paced editing to hide Bob's mistakes or stunt replacements. That allowed Ilya to get longer takes that made the fight feel more visceral and realistic.

In the end, it was OK for Bob's fighting skills to be rough around the edges. That's because the bus fight is the first time we see Hutch transform back into his fighter self, so his character is actually supposed to look a little rusty.

[cheering]

- Two years in the making, and that's only the fights.

Narrator: Bob Odenkirk went from average to action hero, but what about becoming a superhero? That's what Brie Larson had to do when she signed on to play one of the most powerful Avengers.

For her standalone movie, "Captain Marvel," Brie's character had to look believable engaging her enemies in hand-to-hand combat atop a moving train. The only problem? Brie started her career in indie roles and said she was "never particularly active" before taking on the role of Carol Danvers.

At the beginning of training, she couldn't even do a proper push-up or pull-up. For her initial fitness inspiration, she looked to Emily Blunt, who got jacked for "Edge of Tomorrow" so that she could safely wear a 70-pound exoskeleton. Brie sought out Emily's trainer, Jason Walsh, and with him planned out a nine-month training schedule, much of which would take place as Brie was shooting "Avengers: Endgame."

Brie's body kept getting more taught as training went on, forcing the costume team for "Captain Marvel" to adjust her suit more than once. The staples of her program included hip thrusts, split squats, and the dreaded push-ups and pull-ups.

Jason rarely has his clients use machines, but he and Brie did get creative with other equipment, like these weighted chains, which they wrapped around Brie's torso to make her push-up sets even more challenging. Or Jason's own car. He said Brie got it in her head early on that she'd get strong enough to push Jason's Jeep with her bare hands. And by the end of training, she did, for a full 60 seconds. So, basically, real-life superhero stunts.

The physicality Brie achieved through her transformation helped her performance, but so did the mentality. One of Jason's goals was to get Brie as close as humanly possible to the psychology of a superhero, who's pretty much invincible. In the end, he said, "having that physical strength helped her become the character."

It wasn't painless. Jason said there were points where he made Brie cry in the gym.

When Jennifer Lopez and Constance Wu played strippers in "Hustlers," they couldn't fall back on body doubles for the pole-dancing scenes -- the film didn't use any, which meant both actors had to get pole ready. It was OK for Constance Wu to look a little less experienced on the pole. After all, her character, Destiny, is supposed to be a newbie. J. Lo on the other hand, plays Ramona, a veteran stripper at the club who takes Destiny under her wing.

To fit this dynamic, there had to be a clear contrast between Destiny's beginner skills and Ramona's mastery of the pole. In other words, J. Lo had to nail it. She had danced before, of course, on tour and in movies like "Shall We Dance," but pole dancing is a whole different ball game. It requires certain muscle groups to be super strong and no small amount of acrobatics.

That's where pole choreographer Johanna Sapakie came in. A former aerial acrobat in Cirque du Solei, Johanna designed all the pole-dancing scenes in "Hustlers," including Ramona's main routine, which clocked in at four minutes long. J. Lo would have to do multiple takes of that dance at different angles, getting it right every time.

To meet the challenge, the actor moved a portable pole into each of her houses in New York City, LA, and Miami so that she could practice all the time. Johanna started her training with climbing and basic spins, laying down the main principles of pole dancing.

After that, it took a while for J. Lo to develop a fast, smooth rotation on the pole. Spinning can be disorienting at first, even if you're an experienced dancer like J. Lo. As Johanna explained, "When you're a dancer, you spin on top of yourself. As a pole dancer, you're like a carousel going around a fixed point." The last thing to master was the inverted splits. This was supposed to be the "one big 'wow' moment" in Ramona's routine, where she flips upside down on the pole and supports her whole body with just her arms and shoulders.

Inverting and then keeping that position on the pole takes a lot of core strength, a lot of upper-body strength, and an excellent grip. At first, Johanna would spot J. Lo as she practiced pulling herself up.

After two months of training, though, J. Lo was comfortably doing upside-down splits on her own. The actor said that learning the pole dance was "one of the hardest things I've ever had to do for a role."