Lindsay Lohan is apparently dealing with severe pain and is bruised all over since she started taking private striptease lessons from a professional.

The script of her upcoming movie, “I Know Who Killed Me,” which revolves around a young woman played by Lindsay Lohan, imposed her to learn how to strip like a professional.

Lohan's spokeswoman Leslie Sloane Zelnik confirms to Page Six, "She's been in rehearsals for the film and has been taking classes. Her character is a stripper, and she now realizes that the job isn't easy. We should give these women credit."

The story is focused on Aubrey Fleming (Lohan), a woman who is rescued after being abducted and tortured by a serial killer. When Fleming arrives home she claims to be a different person. This poses questions as to whether she is suffering from post-traumatic stress disorder or if something more sinister is afoot.

According to reports, Lohan spent an entire dancing session with Sheila Kelly, developer of the aerobics striptease workout. The 20-year-old actress complained to her friends in a recent e-mail titled “They’re all whores, they’re all whores… xcept for some obviously!” how bad she felt after the training.

"So ... three hours of pole dancing and bruised. Everywhere... I mean we're talkin' like, upper and inner thigh action-bruised... like a walking black-and-blue mark. I mean really though, really, I didn't know it was actually possible to have bruises in such areas of the body. “

“Strippers, dude, I tell you, I really respect [them] now... I'm not gonna lie to you," Lindsay added.

Lohan has been going to clubs while shooting the movie, but hasn't been drinking, the newspaper reports.

Since Lindsay Lohan announced she has been going to AA meetings for over a year now, she is being sober although she maintained her habit of going out often. Reports say she’s keeping away from alcohol.

"When the shoot is over, she is going to focus her attention 100 percent on staying sober and building a more fruitful life," a source told the newspaper. She is considering moving back to New York and leaving behind "the toxic L.A. scene with all those toxic people."