Beefcake Mark Wahlberg is in a fight he can’t win — a fight against time. But the man famous for his hard-core workout routine will go down swinging.

“I won’t lie—the biological clock is ticking,” Wahlberg, 48, admits in the December issue of Men’s Journal.

The Oscar nominee is busy preparing for a big-screen adaptation of the ’70s television series, The Six Billion Dollar Man, but the project has faced delays since the Weinstein Company collapsed.

“Here’s a guy who was a test pilot, and then spent 15 years in a lab to make him superhuman. So I got a window,” he admits. “I don’t want to be the guy playing a part he’s too old for.”

As RadarOnline.com readers know, Wahlberg’s intense workout routine often starts as early as 4 a.m. According to Men’s Journal, Wahlberg’s famed gym is equipped with all the fanciest accoutrements—dumbbells, barbells, kettlebells, VersaClimber, TechnoGym bike, treadmill, rower, boxing equipment and a top-of-the-line body composition machine.

The Boogie Nights star’s latest obsession is “F45 Training,” a group fitness studio that emphasizes functional movements.  He also co-founded Performance Inspired Nutrition, a supplements company that uses all-natural ingredients—vanilla flavor comes from vanilla beans and chocolate from cocoa.

Mark Wahlberg Bulks Up Fight Against Father Time
Courtesy of Mark Wahlberg/Instagram

Wahlberg knows all of this is just to stave off the inevitable as long as possible, revealing a litany of injuries—shoulder, elbow, hand, back, knee, ankle—the result of training so rigorously for so many years. He takes recovery extremely seriously these days, going so far as installing a cryo chamber at his house. He eats very healthy and is considering a move toward vegetarianism.

It’s a dedicated lifestyle, but Wahlberg says it’s all worth it for him – both in his career and life.

“I give it my best and do everything that I need to do to be prepared, and if it doesn’t work, it’s not for lack of effort,” Wahlberg told Men’s Journal. “If I just show up and phone it in—like I’ve seen a lot of people do in the past—and then it doesn’t work, a lot of that is on me and what I didn’t give.” 

Check out the full interview with Mark Wahlberg, and learn more about his fitness regiment, in the December issue of Men’s Journal, on newsstands November 22.