Singer Debbie Gibson on How Her Lyme Disease Will Impact Her Chances on 'Dancing with the Stars'

PEOPLE is celebrating the Sept. 18 premiere of Dancing with the Stars‘ 25th season with 25 days of exclusive interviews, fun retrospectives and new details about what fans can expect from the milestone season.

When Debbie Gibson signed on to compete on Dancing With the Stars, she was finally achieving a goal she had for years.

“From the first season of the show with Joey McIntyre, I wanted to do it,” the singer tells PEOPLE. “It’s such a positive show, and I always thought it would be fun! But the timing just wasn’t right.”

Now the timing is right, but Gibson has another challenge as she dances on the 25th season of the ABC reality dance competition: the singer was diagnosed with Lyme Disease in 2013. (Lyme disease is a potentially debilitating infection caused by bacteria called Borrelia burgdorferi, and is transmitted through the bite of an infected blacklegged tick.)

“It’s a different challenge,” she says. “I can’t be cavalier with my body. I can’t just push myself without thinking what what happens next. [Lyme Disease] can affect my stamina.”

But there’s a silver lining: after fighting the disease for four years, Gibson knows her physical strengths and weaknesses.

PEOPLE’s special issue, 25 Seasons of Dancing with the Stars, is out Sept. 15.

“I’ve always been in tune with my body,” she says. “But the last few years have helped me learn where I can push my limits. I’m going to choose to think of that as an advantage!”

Gibson also believes her years on Broadway will be an advantage in the dance competition — although she acknowledges that DWTS is another thing entirely.

“I can learn choreography,” she says, “but that’s really different from being a technical dancer. So I have to really focus on just dancing, which is going to push me out of my comfort zone.”

RELATED VIDEO: Pro Mark Ballas Teases His Upcoming DWTS Partner in Three Words

Gibson, 47, is one of the older contestants on the show — only Shark Tank‘s Barbara Corcoran, at 68, is older — she believes that age is just a number. “It’s so important for everyone to challenge themselves. There’s always an excuse not to do something, whether it’s your age, or a challenge you’re facing. But the best things happen when you push past your comfort zone.”

Gibson adds that she has a secret weapon: partner Alan Bersten.

“He’s young and hungry and energetic,” she says. “And that makes me feel hungry and energetic! I love working with him. He’s so great.”

“I am just so happy to have this opportunity,” she says. “I’m going to give it everything that I’ve got. However long it lasts, I’ll be grateful for it!”

Season 25 of Dancing with the Stars premieres Monday, Sept. 18 on ABC.