Hugh Jackman on the Difficulty of Keeping His Wolverine Physique

X-Men: Days of Future Past.

It's fairly easy these days to take for granted the sheer amount of actors and actresses putting in tremendous effort to portray physically dominating characters on the big screen. What's impressive about Hugh Jackman and his Wolverine character from the X-Men franchise is that he's been doing it for an astounding 15 years.

"It’s harder at 45 than it was at 30," Jackman tells Men's Health of maintaining his ripped physique . "Even now, I’m noticing the weight starting to go down. You have to work hard. It sucks."

Unlike other actors that are genetically predisposed to bulking up in a short amount of time, Jackman says that his lanky frame means that any time away from the gym makes it that much harder to get it back.

"As Will Smith puts it, ‘It’s easier to stay in shape than to get into shape," Jackman said last year. “Drastic changes are very tough on the body. I never stray too far in terms of my strength training or fitness level; that way it never feels like climbing Mount Everest to get back.”

For his latest outing as Wolverine in "X-Men: Days of Future Past," Jackman knew early on that he would be shooting a nude scene. "There's a naked shot in this one," he told MH. "Not front naked — it's PG-13 — but full-body. So I made it very clear that I wanted to know the date I'd be shooting that stuff.” The actor then took a full three months in the gym to prepare for the scene. When told later on that the shot might be delayed a few weeks, he was adamant about keeping the original timeline.

“I said, 'Absolutely not! I don't care, you can push anything back you want, but I'm naked on that day!'"

Despite his age, Jackman firmly believes that he is at 45 in the best shape of his life. Besides the grueling weight-training and intense 5,000 calorie diet, his discovery of the "16/8 intermittent fast regimen" has made a huge difference. Put simply, the program involves eating all food within an eight hour window and then fasting (with the exception of water) for sixteen hours.

"I feel a lot better on that regime," he said. "My energy is better and I sleep better."

So take heart X-Men fans - we'll like see Hugh Jackman flash those adamantium claws for some time to come.

“I landed the coolest comic book character there is,” he told Muscle and Fitness. “He’s badass, way cooler than me, and as an actor, his complexities, his tortured soul, make him endlessly interesting. The only problem is that the ‘real’ Wolverine doesn’t age, so there definitely is a ceiling for playing this part!”