Jillian Michaels Leaving ‘Biggest Loser’

Trainer says her replacement has already been hired

Trainer Jillian Michaels is leaving "The Biggest Loser" and will use her last season on the show to help introduce her replacement, who has already been hired, she announced on Twitter.

Michaels joined the show on its first episde in 2004, left in 2006, and returned in 2007.

"Season 11 of Biggest Loser will be my last :) have to finish out my contract," she tweeted Friday.

Though she didn't name her replacement, she said she would use "my last season to help launch her in season 11."

The show's tenth season finale airs next Tuesday.