Contestants include two-time Super Bowl champ Damien Woody and tennis Olympic gold medalist Zina Garrison.
The show also replaced Jillian Michaels with two new trainers: Jennifer Widerstrom and Jessie Pavelka.
If Jessie's last name sounds familiar, that's because he is the cousin of former Bachelor Jake Pavelka.
"Everything that you thought you knew about this show has been thrown out the window," said trainer Bob Harper.
Another new twist is Comeback Canyon. After a contestant gets eliminated, instead of going home they'll be surprised by a trip to a secret location where Bob will be waiting.
"Once there are two people at Comeback Canyon, they will have a week with me and whoever wins a weigh-in between the two of them will stay at Comeback Canyon and the other person will get officially eliminated," Bob explained.
An all-new season of The Biggest Loser: Glory Days premieres Thursday on NBC.