Jennifer Lopez made the pole dancing scene in her new movie “Hustlers” seem easy, but a behind-the-scenes video she shared online shows the pain she had to go through to master the skill. The singer and actress had to endure bruises on her legs while practicing, which she shared with her fans online.

In a video Lopez shared on her Instagram page, she showed her fans how hard she had to work to make it seem like she was a professional stripper in her upcoming film. The scene involved the actress playing a character who is such an expert pole dancer that she teaches other women how to do it.

Lopez had to be in peak health in order to pull off some of the challenging moves. Her practice sessions involved her doing some stretching and breathing exercises before pole dancing in front of the mirror with the help of an instructor.

Mastering the initial moments came quickly to Lopez, but the cost of the mastery was that she had bruises all over her legs. This amount of bruising is apparently normal for strippers when they learn pole dancing.

Lopez pointed out in the video that professional strippers actually have a lot of time to master these skills. They can do that at strip clubs every night. However, time is a luxury the actress didn’t have because she had to learn pole dancing quickly to film her scenes for the movie. She described her learning experience as a “crash course.”

Learning how to pole dance was one of the hardest things Lopez has ever done in her life, she said in the video. She has cuts and bruises while filming a few other movies, but she said that she has never been bruised like this before.

The result of all the hard work is visible in the trailer of “Hustlers.” The movie will be released on September 13. Lopez recently shared a still from the movie that is her first scene with Cardi B, who plays a stripper called Diamond in the film.

Jennifer Lopez Jennifer Lopez on 'American Idol.' American Idol/Facebook