In the public eye for more than a quarter century—first as a rapper-turned-underwear model, then as a film actor, and now as a producer/entrepreneur as well—Mark Wahlberg, 46, has always managed to make fitness a priority, even when his travel schedule has kept him constantly on the move.

"My philosophy is it's easier to stay in shape than it is to get in shape," he explains.

Wahlberg's trainer, Brian Nguyen of Brik Fitness, has helped his client maintain a muscular physique by devising quick, compact workouts that can be done just about anywhere—from a hotel room on the road to a trailer on a movie set.

That type of training versatility is crucial for the actor, considering the demands some of his past roles put on him: For example, he had to muscle up for Pain & Gain; shed 60lbs for The Gambler; pack on 20 for Deepwater Horizon; then get super-ripped again for Transformers: The Last Knight, in theaters June 21.

"I like the physical preparation as much as the mental," the star admits.

How it works

This workout uses a combo of dumbbells and a 3/4" superband for two surprisingly robust, low-tech "complexes," or multiple exercises stacked on top of one another without rest. Because you're using the same equipment for several consecutive exercises, you can go right from one to the next without even setting down the dumbbells or the superband. It makes for an ultra-efficient routine—one that Nguyen promises will blast your shoulders and core, and leave you feeling and looking like you're in (Optimus) prime condition.

Directions

Set a timer for three minutes. Perform an exercise for 30 seconds (that's one set) and move on to the next exercise, resting minimally between exercises. After the last exercise, rest one minute. Complete four to six rounds total. Then move on to Part II, and repeat.