Aaron Taylor-Johnson was just another skinny actor until Kick-Ass 2 made him an action hero. Then Godzilla stomped in, and he needed to push his training to a new level

As we were having breakfast in West Hollywood, Aaron Taylor-Johnson had given me a guided tour of his head scars.

“There’s one right there,” he said, pointing to a spot just above his hairline. “See it? That’s from when I was a kid. I was sliding down my mate’s banister and bashed my head open. And the other one …” His finger drifted to the back of his head. “I have no idea. So I must have been pretty paralytic. [That’s Britspeak for “drunk.”] I didn’t even know I had it until we startedGodzilla and they cut my hair.”

The topic had come up as we talked about Taylor-Johnson’s recent film roles, which are becoming increasingly action-oriented. Since his breakout role in 2010’s Kick-Ass, he’s made the transition from heartthrob to hero. He picked up a gun for the first time in the 2012 Oliver Stone pic Savages and packed on muscle—15 pounds, to be exact—for last year’s Kick-Ass 2. This summer’s Godzilla and next year’s Avengers sequel should solidify Taylor-Johnson’s action-star status, but it’s his dedication to building rock-solid muscle that earned him the cover of our May 2014 issue.

Taylor-Johnson is also a man dedicated to his marriage and fatherhood. Appearance-wise, he’s very much a 23-year-old. In conversation, he sounds more like a man in his late 40s, weary from years of responsibility.

Taylor-Johnson is married to Samantha Taylor-Johnson, who’s exactly twice his age, and they have four daughters. A movie star in his early 20s should be going to wild Hollywood parties, not facing the challenges of a growing family, right? “That’s bullshit,” he insists. “They’re not challenges. People are like, ‘Don’t you have to work really hard?’ And I’m like, ‘If you think it’s hard, you must be in a shit marriage.’ “

To learn about Taylor-Johnson’s action-star workout, download the May 2014 issue today! In it, you’ll also find tons of useful stuff—including the ultimate beach-ready workout plan and your guide to surviving at any restaurant—to help you get in the best shape of your life!