Ruben Studdard's time in The Biggest Loser gym isn't just painful for the 462-pound American Idol champ. As a hilarious new clip from the season 15 premiere shows, Studdard's trainer, Jillian Michaels, is having trouble getting to know her new client's, uh, post-workout hygiene habits.

Sweating up a storm at The Biggest Loser ranch, Studdard -- who bested Clay Aiken for American Idol's season 2 title in 2003 -- relishes the idea of kicking back in an ice bath after one of Michaels' grueling workouts. His trainer, on the other hand, finds it shocking. "The ice baths are Jesus in a steel container!" Studdard, 35, muses as he settles himself into a steel tub alongside two female teammates.

"We're going to have to wax that back of yours, I'm telling you right now," Michaels sternly tells Studdard, repulsed by his excessive amount of body hair. "It's not even [just] back hair -- there's an inch-and-a-half of shoulder hair! That is totally unacceptable!"

Studdard, dubbed The Velvet Teddy Bear during his run on Idol, couldn't be more surprised at Michaels' reaction to his lack of manscaping. "Jillian is a hater. I don't appreciate that! I think everything about Ruben Studdard is sexy!"

Watch more of Ruben Studdard's LOL-worthy appearance on The Biggest Loser in the clip above before season 15 premieres Tuesday at 8 p.m. (EST) on NBC.