CrossFit icon's journey from front line to "badass"

Christmas Abbott is a muscular new force in the world of fitness. The CrossFit star built a following by rebuilding herself, becoming battle-tested, inside and out, reports CBS News correspondent Jim Axelrod.

"Calories in, calories out" is a mantra anyone chasing the holy grail of a healthier body has heard before, but to earn the body of a "badass," as Abbott describes in her new book, it will take some more effort.

The 34-year-old, barely-120-pound, CrossFit competitor, Olympic weightlifter and fitness model hasn't always resembled a picture of perfect health.

"I was in terrible shape. I had almost a decade of really destroying my body," Abbott said.

She smoked too much, drank too much and says she could barely run a mile.

"It was devastating to me. At 22 years old, I couldn't run a mile and when I finished it, it took me a week to recover," Abbott said.

That first attempt to complete a short-distance run came during a pivotal time in Abbott's life and in an unlikely place -- the Green Zone in Iraq, where she was working as a civilian contractor.

She said the war came to her camp.

"My first month there and I panicked. I did everything wrong. That was such an epiphany for me. And in that moment I realized I didn't want to die," she said.

Abbott quit smoking and started hitting the gym, but it was an exercise video she saw online that really hooked her on fitness.

"I was just amazed, because there was these three teeny little girls, my size, and they had beautiful bodies," she said. "The girl cries at the end and I was like, 'That's what I want to do. I want to do a workout that makes me want to cry.'"

They were doing CrossFit.

After four years in Iraq, Abbott returned to the U.S. and began coaching CrossFit classes from a park in downtown Raleigh.

She soon opened her own gym and went to work developing her brand: fearless, focused and ferocious. There's nothing she won't try, including a brief detour changing tires on a NASCAR pit crew.

Even though NASCAR is largely a male world, she said she was treated "really well."

"It's never tough to be a woman," she said.

If you boil Abbott and her approach to life down to one word, it's right there on the cover of her book, "The Badass Body Diet"

She said you have to embrace the word "badass."

"It doesn't mean you have to be the most fit, the strongest or the fastest. It just means you have to have the will to try," she said.

Abbott's will is now trained on a climb to the top -- a journey that begins with the bottom.

"I'm concentrating on the booty," she said.

By concentrating on her backside, she said there's benefits for the entire body.

"Like tighter abs, legs, arms," Abbott said.

When it comes to diet, Abbott likes to keep it simple and prepares the same breakfast every day: eggs, peanut butter and an apple.

"You're looking for a balance of hormonal response," she said. "It's every meal, every snack, you need a balance of protein, carbohydrate and fat."

She said to anyone out there who doesn't believe a transformation is possible, "they just have to believe in themselves."

"From someone that didn't believe in myself until my mid-twenties, hell, even towards my late-twenties, I didn't really believe I was capable of what I truly was capable of," she said. "Failure is only failure if you stop trying."

After lifting an impressive 176 pounds and taking first place at a recent weightlifting competition in Spokane, Washington, she earned a spot at the national championships, which will take place this summer.