The Biggest Loser’s very toned, very tough, Jillian Michaels is leaving the hit show after Season 11, which starts airing in January 2011.  The 36-year-old celebrity trainer made the announcement on Twitter:

@ season 11 of Biggest Loser will be my last have to finish out my contract.

And later, she tweeted:

@ yes I want to take a year off TV and focus on becoming a mommy and doing more charity work.

Michaels revealed earlier this year on “The Talk” that she suffers from endometriosis and Polycystic Ovarian Syndrome, conditions that prevent her from getting pregnant, So she must have plans for alternative methods.

But don’t worry about her co-trainer Bob being lonely, Michaels said her replacement is already on board and that she will help break her in when season 11, the show’s fourth couples edition, kicks off next month.

Do you think The Biggest Loser will continue to be such a huge success without the badass trainer??