Meet the trainer who helped Michael B. Jordan get buff for 'Creed' and 'Black Panther'

• Michael B. Jordan has an amazing body, but he used to be much smaller before he starred in Black Panther and Creed.
• Corey Calliet is his good friend and personal trainer, but he doesn't just train Jordan - he also plays a big role on film sets.
• Watch the video above to see the rigorous workouts behind Jordan's physique.

Narrator: Michael B. Jordan is actual body goals. Dude looks like a Renaissance sculpture, but he didn't used to. Ever wonder how he got so jacked? Meet his trainer.

Corey Calliet: I am celebrity trainer Corey Calliet, and I am celebrity trainer to the stars. I love training. When I transform my body, it became an addiction, and it turned into my career. You may see me on a lot of different movie sets, but you have seen my client Michael B. Jordan.

Narrator: He's been training Michael B. Jordan for years.

Corey: So Michael B. Jordan is one of my best friends. We connected on "Fantastic Four" while I was hired to train the cast. He's the only one that allowed me to actually train him. The rest of the cast didn't believe I could do the work, or they were too scared to train with me because I was bigger. We knew Mike. He wanted to get in shape, and when we saw each other, it was like, you know, meeting each other and meeting a new family member at the first sight, and since then on, he's been like family, best friends, train every day all day. That's just what we do.

Narrator: Actors often have to change their bodies between films, but Corey says that Michael's body is a whole other beast. Corey: So, Mike's body changes all depends on the script. It depends on the film. If we need him to be jacked and looking mean, we're gonna change it up. If he needs to be ripped, it all depends on what are we doing. So, "Black Panther" was different. I went back to my, you know, past when it comes to bodybuilding.

I wanted to create something that would actually scare people, look like a villain, make people surprised to see him, make him look intimidating, so we did a lot of weight training. It was a lot of super-compound sets. It was a very, very, very rigorous transformation, and it was different than we did the first time because it was putting on size to get bigger.

Mike loves working his arms. As you can tell, the first time we did "Creed II," he had a peak on top of his biceps, so it looked like he had a bicep and a little one on top. And his least favorite workout... Working his legs. Not saying he has chicken legs, at all, but, doing legs with me, I hate it too.

Narrator: Corey doesn't just train clients. He also plays a big role on set.

Corey: So being on set for me is not just being a trainer. It's being the eyes behind the director, being the eyes behind my client as well, because I'm able to see things they can't see. Of course, when it comes to the body, I'm able to see what I can do to perfect his body to look different, so some shots may need to be more intense, his body may need to look different. A lot of times, like on "Creed II," the director will call, "Corey, how does this look?" Because he's looking at it from a different angle, and I'm looking at it from a different angle, so I'm looking at a viewer that's looking at it to say, "You know what, it's artistic. I like what's going on right here." So I'm a lot involved. I'm on set all day. I'm watching the takes over and over and over again, and I'm giving a lot of input.

Announcer: The challenger Adonis "Hollywooooooooood" Creeeed!

Corey: Every memory I remember about what Mike is like, is almost like going to my kid's graduation, and once he takes his robe off, and you see his body, it's like, we have this thing where we look for each other. He's in the ring. I'm somewhere, but we see each other, and we know we did it, and that's one of my most proudest, and most memorable moments in every movie that we've done.