Sebastian Stan was in the running for the title role in the 2011 blockbuster Captain America: The First Avenger. But he lost out, and instead the Romanian-born actor made waves as the true-blue sidekick Bucky Barnes. Turns out it was a blessing in disguise. Taking on a superhero-size role would have required building a superhero-size physique—Chris Evans reportedly gained 20 pounds of almost comically bulging muscle for the part. Not Stan's style. "I like to be lean and flexible," says the six-foot, 165-pound 30-year-old, who played a scheming heartthrob on Gossip Girl and Sigourney Weaver's drug-addicted son in this summer's Political Animals. "I'm not interested in gaining size."

Which is why earlier this year Stan became a devotee of the aeroboxing workout pioneered by Michael Olajide Jr., who lost a world super-middleweight title fight to Thomas "Hitman" Hearns in 1990 and retired a year later after a fight left him blind in one eye. Olajide became one of New York City's most respected trainers before opening Aerospace gym in the West Village, attracting clients like Mark Wahlberg, Hugh Jackman, Liv Tyler, Eva Mendes, and Adriana Lima. Aeroboxing is, Olajide says, "built for people who live in the city, who don't have the time or the space to exercise outdoors."


Stan says aeroboxing's mix of boxing moves, jumping rope, and strength training makes it the most effective workout he's ever tried. In addition to keeping him lean and toned, the grueling hour-long sessions, which Stan does three to four times a week, have improved the actor's posture and sculpted his shoulders. "You end up in a pool of your own sweat," says Stan, who is starring opposite Twilight's Ashley Greene in the new supernatural thriller The Apparition. "It's hard to keep up with the boxing combinations unless you're really focused, so it's also a great mental workout." Which is why his commitment to this exercise regimen is as much about clarity as vanity. "Working out and working as an actor have gone hand in hand—I always feel more prepared if I know I have done a workout," he says. "It gives me confidence—and peace of mind."

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Sebastian Stan's Workout

Trainer Michael Olajide Jr. customizes his regimen to a client's fitness level. Stan's three-part circuit is repeated nonstop for an hour (usually three to four times), with no rest between segments.

SHADOWBOXING
Eight to 10 minutes, while holding 5-to-15-pound weights. "It's intense cardio that also builds muscle endurance," Olajide says. "You might think five pounds is nothing," Stan says, "but you'll feel it."

CARDIO
Five minutes of jumping rope nonstop—on every count of eight, turn the rope twice under your feet between jumps.


SCULPTING MANEUVERS
Eight to 12 minutes of resistance exercises, at three levels of intensity. Some of Stan's favorite moves:
Standing Ab Work: Use a 15-to-20-pound body bar in a variety of upper-body and core-focused moves, like standing in a split stance and rowing the bar as if you were paddling.

Push-up Variations: Stan does a set of each type for 30 seconds nonstop. Moves include push-ups while holding weights and a version in which you lower your body toward the ground, then shift your weight from side to side.

Squat Variations: Stan does a set of each variation for 30 seconds nonstop. Moves include single-leg squats and tribal squats (weights in hand, knees and feet together, squat, then at the bottom of the squat, jump your feet out, then jump back in).

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