Jennifer Lopez
photo: Splash News

The highly anticipated Hustlers premiered at the Toronto Film Festival this weekend, but the film debuts in the U.S. on September 13. 

Jennifer Lopez, who stars as the lead stripper Ramona, gave fans a tease of what's to come in a behind-the-scenes video shared to her Instagram. While some of the star-studded cast, like Cardi B, were old pros when it came to the pole-dancing numbers, the rest of the ensemble had to take a crash course and learn the moves. 

The fierce dancer, singer, and actor posted a video showing off all that she had learned, and the literal bruises she acquired along the way. In the end, it was clearly all worth it, because Ramona's dancing sequence ended up flawless. 

J.Lo already has a dance background, but stripping and pole dancing was an entirely new genre she'd never explored. 

Lopez had to start with the basics, and had her own trainer, professional pole dancer Johanna Sapakie, to help her learn the extensive choreography for the film. 

Lopez quickly learned that it's not as easy as it looks, and it takes a lot of work to make pole dancing look effortless and sexy. The 50-year-old ended up nailing the choreography after the six-week crash course training. 

The pole completely bruised the inside of her legs, and she shared she'd never experienced bruising this badly for a performance. 

"Every pole girl I've ever met knows that look right there. We're all very familiar with that," Sapakie said in the video, as Lopez admired the bruises forming on her legs after day one. 

"I mean this is just as hard as anything I've ever learned," Lopez said later in the video. "It might be one of the hardest." 

Sapakie joked, "The black and blue issue adds to it." And Lopez full agreed. "I mean, I've gotten cuts and bruises for movies, but I've never been bruised like this for anything I've ever done."

But all the bruises and pain are worth the end result, which is an accurate depiction of pole dancers. 

Throughout the video, Lopez shows off her moves and keeps it real with the pain. The bruises were on full display in this move, but at the end of the video, when she shows off the final product, it is obvious the pain was all worth it. The actor also shared that she wanted the movie to be as authentic as possible, and didn't want Ramona's dance sequence to appear like a "music video" but feel "real, fresh, and specific." 

It's no wonder Lopez's abs became harder than they were before.

Lopez was clearly super fit and had superb dancing abilities that she's shown off during her world tour and televised performances. But judging from her trainer Sapakie's abs, working the pole is the ultimate core workout. Lopez had fun flaunting her rock-hard figure on Instagram in the months prior to the Hustlers release. 

The trailer shows off all the moves that Lopez learned in her training sessions put together. 

It took Lopez four months to learn what takes some pole dancers years to perfect. "Cardi was telling me that it took her years. Like, she's great at it, but it took her years to figure out all of this stuff," Lopez said. 

"I'm just trying to look convincing, as if I've been stripping for a while … I'm comfortable on the pole, and I'm also comfortable with my game. Because my character really has to hustle down," the actor said. After seeing her moves at the end of the behind-the-scenes video and in the trailers, I'd say the training paid off.