THE BIGGEST LOSER -- Episode 901 -- Pictured: (l-r) Bob Harper, Lance -- NBC photo: Trae Patton

The Biggest Loser is back with an all new group consisting of 11 of the heaviest couples in the history of the show. Loser has a track record of success with its contestants and that’s due in part to the dedication of the program’s trainer, Bob Harper.

He sees each new cast come in with not just excess weight, but the weight of the world on their shoulders. It’s up to Harper and his fellow trainer, Jillian Michaels to set them on the right course and inspire them to keep pushing forward.

Click onto video for the challenges Bob Harper faces with each new group of The Biggest Loser contestants.

The two-hour, season premiere of The Biggest Loser airs tonight, 8:00 p.m. ET/PT on NBC.