It’s heroes vs. villains in the all-new, live-action adventure G.I. Joe: The Rise of Cobra, in theaters August 7, and we’re with four of the film’s stars — Sienna Miller, Marlon Wayans, Rachel Nichols and Channing Tatum — who are lucky to be in one piece after filming some of the movie’s more spectacular stunts!

“I think the craziest one I did, they strapped me to the front of a Humvee going about 60 miles per hour swerving through the streets of Prague, which is doubling for Paris,” says Channing, who plays Duke. “It was good, though — didn’t get hurt, thank God.”

Everyone had to get in tip-top shape for their roles, and Marlon, who plays Ripcord, says, “We all worked out really, really hard. … When you’re playing a Joe, you’ve got to be a Joe.”

“We did six weeks of fight training, so we did it the healthy way,” add Rachel and Sienna.

Based on the beloved Hasbro toys that became a comic book and cartoon sensation in the ’80s, G.I. Joe: The Rise of Cobra stars Dennis Quaid as Hawk, the tough team leader of G.I. Joe, an elite, globetrotting unit that takes on the evil Cobra Organization.

“It’s a real fast-paced sort of thrill ride,” says Rachel, who plays Shana “Scarlett” O’Hara.

Sienna, who wore a black wig for the movie as The Baroness, confirms, “It was not a dye job. This is an old-fashioned tale of good versus evil, and historically the good guys tend to be blonde, and lighter, and the bad people tend to have black hair, like witches — it adds to villain-esque behavior. And also, she’s a very famous character within the cartoons and there’s a specific way that she looks, the same with Scarlett with the red hair, and so we had to be true to the characters the way they were created.”

ET surprised the cast with their own action figures from the movie, and Marlon pointed out that when he was a kid, “I didn’t have money for G.I. Joes and fancy dolls that could move and articulate all their fingers and limbs. I had money for the 99 cent [version].”

“But now he does [have money], so he’s got all of them,” says Channing.

“Now you get to be a doll,” adds Rachel.

“Holla!” says Marlon with a high five.

Watch ET for more with the stars of G.I. Joe: The Rise of Cobra!