The Rock Reveals Ridiculous Diet for 'Cheat Days'

As you can tell from looking at him, especially in his upcoming film G.I. Joe: Retaliation, Dwayne Johnson (a.k.a. "The Rock") works hard to maintain his brawny physique. However, sometimes he needs a break from his intense fitness and dietary regime to enjoy a slice of pizza—or four boxes.

Having been immersed in sports prior to acting, Johnson has maintained a muscular figure since his days as a defensive tackle for the University of Miami's football team in the early '90s.

PICS: Actors Who Almost Got the Part

In order to uphold such a well-built physique, the wrestler-turned-movie-star has to stick to a strict diet. However, every once in a while, he likes to unwind from his normal routine and have a "cheat day," which calls for some hefty indulgence.

"It includes at least a dozen pancakes...four pizzas...two dozen brownies and [I] dominate everything," he said of his colossal indulgence on his cheat days.

In the upcoming film, Johnson plays "Roadblock," a G.I. Joe character that will be introduced to the film series for the first time alongside Bruce Willis' "General Joseph Colton." Although he continually keeps himself in tiptop shape, the 40-year-old actor revealed that he had to do plenty of preparation for the role.

VIDEO: 'G.I. Joe' Trailer: Tatum & Johnson Retaliate

"The prep for this was...anywhere between 11 to 14 weeks, [consisting of] diet, conditioning, [and] training," Johnson said. "We already had an established brand of Roadblock in the cartoon...so the look of Roadblock—no one looked like that guy—so it was important to work my ass off and work the part."

Although he may be a strong, manly man, Johnson's co-stars revealed that he was at times slightly intimidated and star-struck by Bruce Willis, whom he idolized as a child.

"I think there were moments where even Dwayne was a little intimidated [to work with Bruce Willis] 'cause he's such an icon," divulged Adrianne Palicki ("Lady Jane"). "I think there were moments where he was like, 'I want to impress him.'"

VIDEO: Dwayne Johnson Talks 'G.I. Joe: Retaliation'

Johnson revealed that he is a big fan of Willis not just because of his films but also because he gave him guidance as he was trying to break into acting.

"To work with him on this movie, I'm so grateful," he said. "I'm just so grateful of that advice...because unbeknownst to him what the advice meant to me, to get that type of support from, at that time, one of the world's biggest movie stars...just says a lot about his character, and I appreciate that."

G.I. Joe: Retaliation is in theaters this Friday (Mar. 28).