Jillian Michaels Jillian Michaels

The Biggest Loser is introducing not one but two new trainers to take contestants through their dramatic weight-loss journey in Season 11, which begins January 4. The reason: Jillian Michaels is leaving the show after the May 2011 finale. The wannabe losers, which include an Olympic gold medalist and the heaviest contestant to date, will be allowed to choose between sweating it out with trusted trainers Michaels and Bob Harper and face elimination each week, or train with the unknown duo and receive immunity for a month.

"I am so grateful for everything the show's given me," Michaels tells TV Guide Magazine. "I'm grateful beyond words. But it just comes a time. It's been seven years. How many times can I say 'last chance workout'?"

Michaels says her reasons for leaving go beyond training fatigue. "I look at the platform that I've been given, and I want to use that platform to say more," she says. "I want to be a part of getting P.E. back in our schools, I want to be on the frontlines of helping organic farms get subsidized by the government. I want to be testifying in front of Congress. This job is awesome, but it's seven days a week."

Michaels says it was her other NBC show, Losing It With Jillian, that made her realize that if she didn't slow down professionally, or at least re-work her schedule, there was another boat she would be missing as well. "I am 36, and I want to start a family," she says. "I'm looking into adoption. It could take three months, six months, two years. But especially after doing Losing It and living with kids, I was like, what am I missing? I'm missing the meaning of life. This is it."

But until next summer, 22 new contestants get to grunt to the drills of Harper and Michaels. And even after that, you never know when the pint-sized trainer may show up. "The show is always going to be a part of me, and I'm always going to be a part of it," Michaels says. "I may come back and do a special work out session. I would never rule that out. But seven days a week — I'm ready to hand that one over."

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