Shawn Johnson is seeing positive results in the ballroom this season on the 15th season
of Dancing with the Stars All-Stars
, but the numbers she sees on the scale after the show's grueling workouts aren't quite as impressive – yet.
"[Other contestants] are like, 'I've lost 10 pounds,' and I'm like, 'Cool, good for you,' " the former Olympic gymnast
, 20, told PEOPLE with a laugh backstage after Monday night's show
. "I think over time, my body will change. It's just different."
Continues the star, "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.' "
Johnson is getting a revived taste of those intensive workouts she once experienced.
"I train before [dance] rehearsals," she told reporters. "I have a Nike trainer I work with every day, one or two hours before I rehearse."
Johnson's fitness regimen is so strict that even ballroom pro partner Derek Hough can't keep up.
"I feel like an old man next to her sometimes," he said, jokingly. "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.' "
As for her meal plan, the athlete steers clear from junk.
"I do the same thing I've always done through training," she explains. "If I go and see an entire buffet, I'll go straight for the protein and that's about it. I feel like everything else is a waste when you're just in a hurry. Chicken and vegetables, that's about it."