The 24-year-old model tells ET she indulges 'all the time.'
Nina Agdal is one tough cookie, in and outside of the gym!
ET caught up with the 24-year-old model girlfriend of Leonardo DiCaprio at Overthrow Boxing Club in New York City on Thursday, where she revealed her ultimate secrets to staying in shape.
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"I always tell myself [working out is] the one thing I won't regret," Agdal, who was promoting Muscle Milk's Coffee House at their Rise and Grind boxing class, told ET's Jennifer Peros. "Like, you'll always regret that slice of pizza, you'll always regret that glass of wine, [but] you'll never regret a good workout."
When it comes to getting fit, Agdal says she likes to switch it up. "I do so many different things," she explained of her workout routine. "I do Y7 Yoga, I take a lot of Akin's Army classes, soul cycle, boot camps, tone house, SLT, boxing. I do everything."
Agdal said she especially loves boxing because it forces her to tone every muscle.
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"You get every element in it," she dished. "You have the strength, you have the cardio -- it kind of feels like a sport, so you can always be better. It's just really fun."
Although the Victoria's Secret model tends to keep her diet healthy -- "I eat a lot of Greek yogurt with honey, a lot of lean protein, vegetables" -- she admits she indulges "all the time."
"I'm not gonna lie, I'm kinda the worst with a diet," she joked. "If I have to cheat, I'll have a Frappuccino with whipped cream, but I can't do that every day."
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"When I have a really big shoot," she added, "I start thinking about the calories and how much I'm eating compared to how much I'm working out. I think it's a balance -- you can't go too crazy about it because then it just becomes way too restricted."
Clearly, what she's doing is working. The Denmark native slayed the red carpet at the Sports Illustrated Swimsuit Summer of Swim Fan Festival and Concert in NYC in August, flaunting her sexy figure in a dress that featured two thigh-high slits.
And while she doesn't mind posing for photographers on the red carpet, Agdal confesses she's not a huge fan of being photographed in her bathing suit -- one of the downsides to dating an A-list actor.
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"You try not to eat a huge sandwich before going on the beach if you know there's going to be, like, paparazzi or anything like that," she said. "But it's like, you just gotta deal with it."
Agdal and DiCaprio were most recently spotted out and about in the Big Apple. The blond beauty went makeup-free for their outing, which included a stop at Bar Pitti for lunch.
Although Agdal's beau is an Oscar-winning actor, she told ET that, right now, she doesn't have any plans to take her talents to the big screen.
"I'd rather be, like, naked in front of a hundred people than act right now," she said. "Don't quote me on that later!"
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Back in May, a source close to the couple revealed that Agdal and DiCaprio, 41, began dating after he invited her to the Cannes Film Festival. Interestingly enough, they were first linked together as far back as February 2014.
"Leo definitely courted Nina in the beginning," the source explained. "She wanted to make sure she wasn't just another one of his models. They're really happy and having a lot of fun together." Hear more in the video below.