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By Scott Huver and Jessica Wedemeyer

Parenthood is messy -- just ask Jillian Michaels. The "Biggest Loser" trainer learned firsthand since becoming a mother of two in May 2012 that smelly diapers and spit up aren't just horror stories -- they're daily occurrences.

"I did not anticipate how much a child under 1 throws up -- oh my God, every day," Jillian told Wonderwall while promoting "The Biggest Loser" at the 2013 Television Critics Association winter 2013 press tour in Los Angeles. "Every day, I just look at [my son], and I'm like, 'Phoenix, honey, when do you stop puking?' I'm told that it's after a year, but there is not a day where I do not get projectile vomited on -- not a day!"

Jillian's partner, Heidi Rhoades, gave birth to their son on May 3, 2012; that same week, the couple brought their daughter, Lukensia, home from Haiti after a two-year struggle to adopt. Now the couple is reveling in the dirtier parts of parenthood -- and projectile vomiting isn't the worst of it!

The fitness expert shared her most embarrassing parenting horror story, which began when she attempted to change Phoenix's dirty diaper while visiting a physical therapist's office with Heidi -- and ended with the couple seeking a new physical therapist!

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"I didn't want to take [Phoenix's] shoes off, so I was like, all right, I'll pull his pants down and take the diaper off that way and kind of weave it through his legs," Jillian recounted. "But it was a poop diaper, so when I pulled the diaper through the legs, crap went flying -- all over the floor, all over the wall."

"I kind of died that day," she adds. "I kind of died inside. [The physical therapist] was like, 'It's OK, I have two kids.' But we knew it wasn't OK, and we've never gone back."

So Jillian is eagerly anticipating the day when dirty diapers are a thing of the past and she can share some of her less cringe-worthy hobbies with her children.

"I have this vision of doing [parkour] with my son one day," she says. "It's like, we're going to do Brazilian Jujitsu together; we're going to do parkour together. Then I know he's going to be like, 'Mom, I want to take ballet!' So we'll see."

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The mother of two has been enjoying parkour and free running classes recently to keep her buff bod in top shape -- "It keeps [exercise] fresh and different," she says. "Essentially you vault and jump and climb things. It's very fun. It's a kid thing, but I've fallen in love with it."

But the super-fit mom knows that exercise is only part of the equation when it comes to raising a healthy family. She's long been incorporating healthy options into her kids' diet -- with a little clever manipulation, of course!

"At 2 1/2, I can still manipulate [Lukensia]," Jillian shares. "So it's like, 'All right, I'll give you this treat if you eat that,' but, of course, the treat is an organic graham cracker, and she doesn't know any better. … I'm trying to help [my kids] find balance so it isn't this foreign thing where they've never had a cupcake. It's like, sure, we have cupcakes, but we do it in moderation. We eat this good and then we can eat that bad."

The personal trainer also believes that healthy eating during pregnancy will predispose children to healthy food options.

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"There have been some studies that suggest that your baby as a fetus can actually develop a predilection for certain foods, so eat vegetables when you're pregnant and then make your baby purees," she suggests. "Heidi does it -- bless her heart. Feed your baby vegetables and find things they like. Phoenix hates green beans, but he likes butternut squash, so we work with it."

Well, if it works for Jillian, it works for us!