During an interview on "The Tonight Show with Jimmy Fallon" on Monday, Kidman's "A Family Affair" co-star Joey King discussed what she had learnt from working with the Academy Award-winning actress on the Netflix film, which also stars Hollywood hunk Zac Efron.
"They're both like so hot," she said Fallon of the actors, who are 57 and 36, respectively.
"They were the fittest people I'd ever met, so they encouraged me. So I became, you know, a tubular gym rat on set."
"[Nicole] taught me like the most epic, awful butt workout I've ever learned in my life," she told me. "I was like, 'I'm a youngster. I can hang…I'm agile. King, 24, said, "I thought I could hang, but I couldn't."
"It was all these donkey kicks, and the rainbows, and you know, the fire hydrants," she explained, giving the evocative titles of popular exercises.
"But you have to keep your leg in the air for about 12 years." "It's so difficult."
Since filming, King has integrated the difficult regimen into her own workout because "it's the most effective,"
and she said that she frequently texts Kidman photographs, joking that she should "call an ambulance."