Gigi adorably shares that she sings "Broadway show tunes at home" as a stress reliever. "I love 'Popular' [song] from Wicked," she confides. "That's the only one I'll tell you about because I know at some point someone's going to ask me to do this, and that's the only one I'm willing to do publicly."
She even gets Zayn Malik in on the fun. "My boyfriend gets into it too," Gigi exclaims. "He's a big goofball -- we laugh a lot."
As for her diet and workout regimen, Gigi subscribes to a great personal motto of, "Eat clean to stay fit, have a burger to stay sane."
She also admits that she's not very good at hitting the gym. "I rode horses and played volleyball back home, so when I came to New York it was hard for me to just go to the gym," she explains. "I need to have a sport that wakes me up and that I can get better at, and boxing does that for me."
The "Shake It Off" singer also attended Hilfiger's runway show during New York Fashion Week, and Gigi was eager to brag to ET about her pal. "She's obviously such a great friend," she gushed over Swift. "And, you know, she is starting to go back to work in the studio again, and really made time to be here for me, and I am so grateful for that."