Boyd Holbrook is a changed man. After spending 14 hours a day for the past two years on the sweltering Colombian set of Netflix’s series Narcos, in which he plays a DEA agent chasing drug kingpin Pablo Escobar, Holbrook didn’t have much time, or desire, to hit the weights.

But that was before he joined the Marvel universe as Donald Pierce, the jacked, mutant-hating cyborg and robotics genius who battles Hugh Jackman’s Wolverine in Logan (in theaters March 3). Naturally lanky, Holbrook realized he needed to add weight to his 6’2“ frame. Not a simple task.

How much time did you have between shooting Narcos and Logan to get into shape?

I had only about a weekend, so I had to start my training in Colombia. I didn’t even have a trainer, so I’d do a sort of prison-yard workout. I used a pullup and dip structure and a bench I put in my bedroom so I could do 45 minutes in the morning, then come back after filming and do another hour and a half.

Plus, Colombia has hills everywhere, so I’d go for runs with my dog and do burst sprints.

What changes did you make to your day-to-day lifestyle?

I started getting 4,000 calories a day and stopped eating carbs and sugar, which is the devil. I also cut out smoking and drinking. I ended up putting on 25 pounds of muscle.

Once you were on set, did Hugh give you any tips?

I learned by watching him. Hugh’s a machine. He’s always got weights lying around, and sometimes before we’d film a crucial scene, like a really intense fight, we’d swap weights or do a few sets of burpees just to get the blood flowing.

Did you work out away from the cameras as well?

Hugh invited me to come train with him in the mornings. We’d do circuits with heavier weights, then mix in CrossFit-linked workouts. We’d warm up with a 1,000-meter row, then do 3 sets of 50 box jumps, a 2,000-meter row, and 20 wall balls—each in under 12 minutes.

We filmed all over the U.S., and it was important to maintain a workout rhythm. In New Orleans, we’d go to a 24-hour gym, and in New Mexico—where we finished the film—we’d run to the set together.

Hugh’s about working out whenever he can.

Are you aiming to be as ripped as he is?

Yeah, come March [when Holbrook’s next project, Predator, starts filming], me and Hugh might have to arm wrestle.

Who’d win?

Probably Hugh. But by March, I’m gonna be trouble.