NEW YORK (AP) -- So how do you ask 85-year-old Supreme Court Justice Ruth Bader Ginsburg to let you bring video cameras into the gym to record her workout?
The answer, according to the makers of the "RBG" documentary that's in theaters now and bound for CNN later this year, is "very meekly."
A trainer pushing Ginsburg on the free weights provides one of the smile-worthy moments in the documentary, which puts meat behind the cultural phenomenon created by the 2015 book, "Notorious RBG: The Life and Times of Ruth Bader Ginsburg." The film's story traces her legal work advancing rights for women leading up to her 1993 elevation to the top court, and her role as a justice since.
Mixed in is the tender love story with her husband Martin Ginsburg, who died in 2010, and rich personal touches including her friendship with the late Justice Antonin Scalia -- bringing a liberal and conservative together in a way that seems alien to modern Washington.
Watching the "Notorious RBG" fame, film director Betsy West said that "we felt that many of her millennial fans didn't know her full story." West and co-director Julie Cohen set out to tell it.
When they first approached Ginsburg with the idea, her answer was "not yet."
"We noticed the two words not in her email to us were 'no' and 'never,'" Cohen said. So they got to work, and later Ginsburg cooperated with interviews.
Ginsburg met her husband as an undergraduate at Cornell University. When she was admitted to Harvard Law School, a dean famously asked her and the other eight women in the class why they deserved to take a place in the class that should have gone to a man.
It was a far different time. Ginsburg attacked sexism methodically while working for the American Civil Liberties Union, using the words of the Constitution to fight gender roles that had been enshrined into law. She won five of the six cases she argued before the Supreme Court.
Filmmakers outline that effort by mining archives with tapes of her legal arguments. Research also uncovered one priceless moment in Ginsburg's confirmation hearing to the court. As the still-novel idea of women on the court was being discussed, the camera pans to senators at the hearing where, behind them, a young legislative aide and Ginsburg's future colleague on the court, Elena Kagan, was working.
Ginsburg provides a still-relevant model for activism, Cohen said -- even if her quiet, persistent, "long game" strategy can make younger idealists impatient.
Cohen and West's portrait is mostly loving, although Ginsburg's unusual criticisms of Donald Trump when he was a presidential candidate were addressed. Trump's supporters didn't like them and many Ginsburg fans thought them ill-advised.
Perhaps unexpectedly, the film received a three-star review (out of four) from the conservative website Newsmax.
"You can completely disagree with everything Ginsburg has ever done as a lawyer and/or a judge but as a subject for a non-fiction film, she has few peers," wrote Newsmax's Michael Clark. "Like it or not, Ginsburg's story is captivating and ideal fodder for a movie."
The film began appearing in a limited number of theaters this month and is starting to expand its reach this weekend. The one critic Cohen and West were most interested in saw it for the first time at the Sundance Film Festival. Cohen and West sat across the aisle from Ginsburg, stealing nervous glances.
"As it went on, I think we started to relax because she was completely engrossed throughout," Cohen said. "She laughed repeatedly, she pulled out a tissue and cried a number of times, including in an earlier scene of watching herself watching a beautiful opera duet that she loves. Wouldn't have occurred to us as being ... a strong emotional point in the movie, but that really seemed to move her."
For the workout scene, it had been West's job to ask if Ginsburg would allow a camera. The request was met, as was often the case, with a dramatic pause. Then came the answer: "Yes, I think that would be possible."
"We weren't in that room for more than a few minutes, then we knew why she'd let us film this," West said. "She's an elderly woman who is keeping herself in very good shape to do the job that she loves and I think she's proud of this."