Bob screams at a contestant, says he was “cussing like I’ve never cussed before”

Bob Harper, the more mild-mannered Biggest Loser trainer who has described his work as “God’s calling,” unloaded on a contestant during Tuesday’s episode, resulting in more fireworks than were on the first episode of American Idol 8.

Before Bob started screaming, he said in an interview, “I was so pissed during that last chance workout because I just didn’t think she was doing what she was capable of.”

Once Joelle stopped running on the treadmill, Bob screamed, “What the fuck, Joelle? … You stop at 20 seconds every fucking time.” He kept screaming at her, and Jillian was thrilled. “I have never seen Bob that mad. Never!” she told her trainees.

Watch Bob flip out:

The Biggest Loser: The Blowout [Hulu]