What a feeling! Jennifer Beals gave 'Flashdance' heart, but uncredited dance double did the moves

Jennifer Beals went from wide-eyed acting newcomer to movie star and 1980s fashion icon in "Flashdance" 40 years ago.

Audiences were swept up in Beals' performance as Pittsburgh steel mill welder Alex Owens, who lives a double life as an exotic dancer with dreams of becoming a professional in the movie, which hit theaters on April 15, 1983.

While Beals gave Alex heart, the character's famed, intricate "Flashdance" dance numbers were almost entirely performed by uncredited French pro dancer Marine Jahan, whose moves were interspersed with shots of Beals dancing from the neck up.

"Most of the shots are Marine dancing and Jennifer's head," director Adrian Lyne says of the romantic drama (now out in a 40th anniversary 4K Blu-ray edition). "It was great to have two people doing one part. It's funny how the audience accepted the sort of amalgam of the two. They didn't really think about it being another dancer."

Who was the real dancer in 'Flashdance'?

In the dance number set to Michael Sembello's "Maniac," it is Jahan's feet bouncing on the floor, which kicked off the legwarmer trend of the time. It's Jahan who's seen in silhouette, doused in water, in the iconic wet dance.

In some instances, Jahan's face is shown on camera only slightly obscured beneath Alex's wig – "a wig that kept falling off" Lyne says. "And the interesting thing was Marine and Jennifer had very different bodies."

The climactic conservatory audition dance scene, set to Irene Cara singing the Oscar-winning song "Flashdance ... What a Feeling," was even more complicated. Alex stumbles during the audition, then goes into her own sensationally choreographed number that required even more body doubles than Jahan.

Gymnast Sharon Shapiro performed the tremendous dive into a roll that leads into a breakdance performed by Richard "Crazy Legs" Colón, who grudgingly donned a wig and tights ("He was very unhappy about wearing the tights," Lyne remembers) to appear as Alex.

Lyne maintains it was the movie studio's decision to gloss over the stand-ins to foster the illusion of Beals doing it all.

"Jennifer was a pretty good dancer, but she wasn't like Marine," says Lyne, who was directing his first major film. "The studio really wanted to keep it under wraps. And the more they tried, the more the press pounced on it. Because obviously, it was a body double. But if anything, the controversy was good for the movie. And it's funny that we're still talking about it 40 years later."

Jennifer Beals was a force in 'Flashdance'

Lyne gives major credit to Beals' portrayal as Alex for the success of "Flashdance." Upon meeting the aspiring actress, who had appeared in 1980's "My Bodyguard," the director knew he had found his Alex.

"I went running over to (producers) Don Simpson and Jerry Bruckheimer to tell them how great she was."

Besides having the acting chops to earn a Golden Globe nomination, Beals' glow enhanced the love story with Alex's mill boss Nick (Michael Nouri). "She was devastatingly beautiful without any kind of awareness of that beauty. That lack of awareness was really lovely. And she had that sweet laugh, like a kid."

Director Adrian Lyne has one 'Flashdance' regret

Lyne has one regret: a line cut from Joe Eszterhas' script involving an upscale dinner scene with Alex and Nick. When Alex receives her meal, it has broccoli.

"And Alex says, 'What are these little trees?' " Lyne says. "I thought it was charming, the best line in the script."

But a studio executive insisted the line be taken out, and Lyne allowed the cut. "I was a first-timer. I didn't have the (nerve) to hang on to the line. So every time I see that scene, I wish Alex had said that line about the trees."

But that's small potatoes. For a movie with minimal expectations and without major stars, "Flashdance" was considered a modest success when it debuted with $4 million on opening weekend. It steadily grew into a culture-changing hit with more than $200 million at the box office worldwide, making it the third-most popular movie of 1983.

"What's extraordinary is it just sat there making money, week after week," Lyne says. "It was ridiculous."

Keep the feeling: Read on about 'Flashdance'

• Irene Cara, Oscar-winning 'Flashdance' singer, dies at 63: 'Beautiful genius'

• Shaq explains his Jennifer Beals, 'Maniac' love: 'Dancing makes you more athletic'

• What a feeling! Break out the legwarmers, because 'Flashdance' turns 35

• Ryan Reynolds channels 'Flashdance': See the inspiration in his 'Deadpool 2' poster

This article originally appeared on USA TODAY: 'Flashdance' 40th anniversary: Jennifer Beals relied on movie magic