'The Flash' star Grant Gustin shares how he got the part of the superhero

'The Flash' centers on Barry Allen (Gustin), who is struck by lightning and becomes the fastest person alive. 'The Flash' debuts on the CW on Sept. 7.

When Grant Gustin found out he got the role of a lifetime, the lead of The CW series "The Flash" (Tuesday at 8 p.m. EDT) as Barry Allen, a young man who gets struck by lightning and becomes the fastest person alive, his wait to begin shooting was anything but quick. It was a good nine months before he would suit up and head to set.

"I'm glad I didn't break a leg or something," joked the 24-year-old Virginia native in an interview.

TV viewers got a sampling of Gustin as Allen last year, when he appeared in two episodes of The CW's "Arrow" (before his character becomes "The Flash.")

That in itself was a big deal.

"It was the most scene work I had ever gotten to do on camera. Even though I was guest-starring, it felt like a big role already. It was really cool, really cool," recalled Gustin.

Prior to "The Flash," he was best known for a recurring role on Fox's "Glee," playing a high school student in a rival glee club.

Gustin believes his dance background helped him land the role of Allen.

"I don't run like any type of athlete. I stopped doing any organized sports at 10 and started dancing. I'm athletic but in a dancer way," he explained. He's also "naturally lean" and now works to keep his endurance up so he can run on a treadmill in front of a green screen for running shots in "The Flash."

The casting process was a long one. He had "about six auditions over a couple months ... including the testing process." He didn't feel confident until he started researching and discovered similarities to actor John Wesley Shipp, who played "The Flash" on CBS for one season in 1990. (Shipp plays Gustin's father in The CW version.)

"We're both from Northwest Virginia and our birthdays are like days apart. (That's when) I started putting it out into the universe that I would get the part."

Once he did, he realized "'Oh my God, I just booked this. Now I'm gonna have to go do it!'"

Putting on the costume has been a treat.

"I've literally laughed because I'm wearing it, I've taken so many hilarious selfies that nobody will ever get to see because I would get in trouble," Gustin said.