They got a diver in to teach her, and she even got competitive with it, saying it was "kind of like meditating underwater".
"It’s all about lowering your metabolic rate…You kinda, like, meditate underwater. It’s what free-divers do, but it’s amazing," said the 26-year-old, wearing Elie Saab.
She hit her own personal record of five minutes, but when her stunt double hit the record of five and a half minutes she was almost going to go in for another session to improve on her PB!
"I got to five minutes and I was like, 'You know what? This is above and beyond what I thought I’d get to. I’m good, I’m good with five.'"
Watch the interview here: