AceShowbiz -

Shawn Johnson admitted she's having problem of losing her weight during her current participation on "Dancing with the Stars: All-Stars". Despite going through vigorous rehearsals to master her moves, the 20-year-old athlete said she hadn't lost a single pound.

"[Other contestants] are like, 'I've lost 10 pounds,' and I'm like, 'Cool, good for you,' " the gymnast told PEOPLE backstage after "DWTS" performance show on Monday, October 1. The Olympian gold medalist added, "I think over time, my body will change. It's just different."

"Especially coming from Olympic training, I'm used to seven hours a day of the hardest workouts, so it takes more. It's not like the others who are like, 'Oh, I lost 13 pounds in two days,' " continued the winner of "DWTS" season 8.

She retired from competitive gymnastics last summer due to knee injury. Now that she's back competing in the ballroom, Shawn returned to her intense workout. "I train before [dance] rehearsals," she said. "I have a Nike trainer I work with every day, one or two hours before I rehearse."

Her pro dancer partner, Derek Hough, jokingly chimed in, "I feel like an old man next to her sometimes. She's like the energizer bunny. She's like, 'Let's go again.' I said, 'Listen, I don't run 10 miles before I rehearse.' She's like, 'I've been up since 5:30 A.M.' "

Shawn and Derek survived elimination this week. Joey Fatone and Kym Johnson were sent home in the second week of the dancing competition.