If you’re an A-list director filming an action-comedy-drama about a couple of bodybuilders scheming to kidnap a wealthy client, Vegas odds would look strong for two men to survive the casting call: Dwayne “The Rock” Johnson and Mark Wahlberg.

At 6’5, 265 pounds, Johnson already looked the part for his role in Pain and Gain, the new Michael Bay movie that hits theaters this weekend. Wahlberg, however, had recently slimmed down to a trim 160 pounds to play average guy John Bennett in Ted. In two months, the actor packed on 40 pounds of muscle to achieve the hulking, action-hero physique necessary to avoid being dwarfed by his mammoth co-star. (Compare Wahlberg's routine to the life-changing workout he used to get lean in 2010's The Fighter.)

So how’d he do it? Heavy, heavy, weights and lots of protein, we learned in an last week:

Men's Health: I heard you were eating like ten meals a day.

Mark Wahlberg: More like twelve.

How's that even possible?

Well, sometimes you have to get up in the middle of the night for a meal.

So you weren't sleeping either.

Not as much as I wanted. I'd have a big meal and go to bed at 9pm, and then I'd get up at midnight to eat again, and I’d still be full from the last meal.

That sounds horrible.

It kinda’ was. And then you exercise first thing in the morning and eat all day, and you try to take as many naps and rest as much as possible. Especially after eating, because you feel like you’re growing while you’re sleeping.

What kind of workout routine did you follow to pack on that much bulk?

Well, I'd wake up at 4:30 every morning, have a nice big breakfast—a pre-workout igniter—and then I'd hit the heavy weights, depending on the day and the routine for the day. But it always involved lifting heavy, and mostly just lifting weights. And then a protein shake right after the workout. And then chicken, steak, fish, a little bit of pasta here and there. Just really overloading, meal after meal after meal.

Please stop.

Chicken and burgers and…

I can't take it. It feels like something they'd do in Guantanamo, force feeding you till food loses all pleasure.

Food really did stop having any real taste for me.

Method acting is fucking brutal.

You do what you've got to do.

Do you like to work out alone or with other people?

I have a guy who works out with me in the morning now. And I have my friends who are into working out. But I have a gym at the house so I don’t usually get to the gym all that often. If I’m away, I’ll work out with somebody. I like that back and forth, where they're pushing you or vice-versa.

When shooting Pain & Gain, did you work out with the Rock?

Nope. We had very busy twelve hour days, so he’d train while he was home and I’d train before I got to the set. (Pain & Gain co-star) Anthony Mackie and I worked out a couple of times. And when we were shooting at the gym location, everybody would mess around.

Are there ways of making it fun? When you're doing intensive, seemingly never-ending workouts like you did preparing for this movie, how do you keep from going nuts?

It depends. If I’m training for a specific project, then I just keep my eye on the prize. It's not something I do every day of every month of every year. It's for specific projects. After we finished Pain & Gain, I went right into 2 Guns (with Denzel Washington), so I immediately had to lose 30 pounds in 30 days. So I started playing basketball right away, full court basketball every day to shed the weight. And then I changed my supplementation program.

Your character in Pain & Gain gets off on the pain of pumping iron. Do you love that pain?

No, I love the relief of being done. I love the protein shake five minutes after the workout is over. It helps you feel good throughout the rest of the day. When I don’t exercise and when I’m not eating good and clean, I feel sluggish. So it’s good to get it done, especially if you're tired or sore.



Continue reading our interview for Wahlberg’s take on bar brawls during the filming of Three Kings, fighting off a chimpanzee obsessed with Helena Bonham Carter, and what exactly happened to Dirk Diggler’s most famous appendage from Boogie Nights.