<div><div>The actress is fighting fit thanks to her tough new role</div></div>

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Hello, hot mamma! Katie Holmes is rocking her fiercest figure ever and we are bowing down. So how did the mum-of-one, 39, get so ripped? Well, it’s all thanks to an upcoming role she’s prepping for as an ex-marine in thriller The Doorman.

“I wanted to be authentic to a person who trained in the military,” Katie tells.

While the star has long been a keen runner – she completed the New York City marathon in 2007 and says, “I prefer a long run because I love the runner’s high” – weights have also played a huge part in sculpting Katie’s enviable new body. And research has shown that a combination of cardio and strength training can help you lose about 9kg in less than three months.

“I was a five-pound-weight [2.2kg] person, now I can do 15 [6.8kg], 20 [9kg],” Katie reveals.

The Dawson’s Creek alum is also a fan of yoga and Soul Cycle, and recently fell in love with boxing. “I’d never done it before, but it’s thrilling. You can get out the stress of the day and it puts me in a much calmer place. It’s a really fun, empowering workout.”

Of course, Katie’s also given her diet an overhaul. “She sticks to a high protein, low-carb diet,” an insider tells.

But while Katie mostly eats plant-based foods, she also treats herself to the occasional slice of pepperoni pizza or half a cheese quesadilla. “It used to be about fitting into my jeans and I’m so s