You were jacked in Meet the Spartans. How did you prep for that role?
That was the most ripped I've been in my life. My parents saw me for the first time when they went out and visited me, and they didn't even recognize me. They say you're not allowed to eat so much fruit, because it's got a lot of sugar in it. But it's natural sugars. I ate a lot of fruit. I ate a lot of protein and salad, obviously, but at night, when a lot of people snack, I would eat grapes and frozen bananas. That was my secret. And at night, I would eat as much as I wanted, get my kick, and it wouldn't hurt my physique.
So you credit nutrition?
Nutrition was a big part, but the first day we got on set, I started talking to some of the stunt guys, and they actually worked on 300. And they had to go through the crazy workouts those guys did. Everything I would do, I would do supersets. A push, then I would do a pull; a chest exercise then a back, a bicep exercise then a tricep exercise. Then an ab and a squat. Twenty reps of each, back to back, for four times. So you would get cardio as well as muscle training. I would also sprint in the morning, I would sprint 60 yards, jog 60, sprint 60, jog 60, all the way to the gym. Then on the way home, I would just jog. It was immense cardio.
How long did it take to prepare?
Physically, it took three weeks. Then I got strict once I got to the set. Nutrition is the main thing for me, because if you can limit the amount of calories you intake, and if you watch the amount of fat you eat, that's the biggest thing for me. People say you must not eat . . . no, I eat, and I eat a lot, but it's just about eating right.
How about those abs?
I did insane . . . insane supersets, where I was making up shit as I went along. I would choose five or six ab exercises. I would do 20 reps of each, and that was one set. And I would do three sets. I'm basically getting 300 reps. I would always do weighted abs, like ankle weights or a dumbbell between my legs, to start really ripping them up.
How did you train for your role in Friday the 13th?
Whenever I'm on set, I'm very focused on continuing my cardio, my workouts. I feel like if I work out, and I have that part of my life focused and balanced, everything just falls into place. For every role, I make sure to go in there in great shape, with a healthy, clear mind, and ride that all the way through the shoot.
You find out you got a role in a movie. How long before your ass is in the gym?
Luckily for me, I consistently work out. It's not like, "Oh crap! I gotta get in shape to work out!" It's all about fine-tuning and being disciplined. I just start setting myself up to be stricter and stricter so that when I'm on set, I'm already in flow.
How long was the shoot?
We shot for two months, and the hours were so up and down. So many night shoots, then we would do quick turn-arounds and shoot the next day. You had to be ready for anything.
Given the unpredictable nature of the shoot, how did you squeeze in workouts?
Luckily, the cast would play basketball a lot. I would go run in the mornings before I would shoot. The main thing I do, if I know I have a really long day, if you go for a 20 min jog, you'll end up burning 600 calories. No excuses.
Gym rat or outdoors guy?
I would say more outdoors. I cycle . . . sometimes I would go for 60-mile rides. I competed in a triathlon.
The Malibu Celebrity Triathlon, right?
It happened Sept. 14. I got fourth place . . . and it was my first triathlon.
I think it's important to note that you beat Matthew McConaughey.
Believe it or not, that was good motivation. I get to my transition spot, and see all this paparazzi there [for Matthew], and I thought: OK, competition is on. I would definitely do another [triathlon]. If I give myself two months, I know I can win. It was for a fantastic cause . . . for the Children's Hospital. But at the same time, it was a chance for me to challenge myself.

A lot of "bad guys" in film exhibit superhuman strength. How would you assess Jason's fitness? How fit is the new Jason?
Jason . . . is a beast. [The guy who plays him] Derek Mears is a beast. This guy is 6'6, 250. He's solid. He does mixed-martial-arts training. This new Jason is the most badass Jason. He's a very fit guy, he's been involved with stuntwork in the past.
Who would you say could bench press more: Jason or Michael Myers from Halloween?
I would say Jason! At least, I'm kind of contracted to. [Laughs]
Friday the 13th is in theaters now.