The Biggest Loser

New trainers Anna Kournikova and Dolvett Quince join "Biggest Loser" favorite Bob Harper, training contestants in an unprecedented "Battle of the Ages".

Contestants only get to use the gym two hours a day, and Dr. Huzienga delivers sobering health news to the players.

NFL stars Clay Matthews, Drew Brees, Tim Tebow, Tony Gonzalez, Shawne Merriman and Eric Dickerson guest star.

Past season fan favorite Hannah Curlee, Adam Hurtado and Maric Crozier return to cheer on the team representing their ages.

One contestant goes home and takes their trainer with them.

Halloween week brings a candy temptation and a haunted maze challenge to "The Biggest Loser" ranch.

Contestants switch teams and trainers after a game-changing challenge.

Chef Devin Alexander and Season 11 winnner Olivia Ward guest star.

Apolo Ohno guest stars, and the seven remaining players compete in a pentathalon.

Trainers prepare a healthy Thanksgiving feast for contestants, who later face their toughest challenge so far.

Fan favorites return for a thanksgiving special featuring never-before-seen footage, hilarious bloopers and a surprise announcement.

Celebrity hairstylist Ken Paves and fashion expert Jeannie Mai help transform final five contestants in must-see makeover episode.

All contestants return to run a marathon, with the winner securing an automatic spot as a finalist.

"The Biggest Loser" revealed in exciting season finale!