You likely know Jason Derulo from his debut 2009 single, “Whatcha Say.” The crooner's back again with his latest hit, “If I’m Lucky,” for which he’s created not one, but two music videos that resemble mini-action films, which may have turned into earwigs over the start of fall. But did you know the singer is fitness guy who's really into boxing?

That passion started when he was a kid, after taking lessons for several years and ultimately led him to invest in Rumble Boxing gyms—alongside silver screen boxer Sly Stallone and actor Ashton Kutcher. Credit for his fit physique is partially due to hopping in the ring, but also from being resourceful with his workouts when he can't find a boxing gym.

Related: Try this boxing-inspired exercise that will sculpt your core

“You have to be really creative and not be afraid to look foolish," Derulo told us. "I’ve done anything from lifting my suitcase as dumbbells to just doing crazy amount of pushups.” While he loves everything from sprints to jump roping to boxing, his favorite workout is muscle-ups, a full-body exercise that targets your core, arms, back and chest all in one explosive movement. (Check out how to master the muscle-ups yourself.) He also likes to do strength training, following up with a daily two-to-four mile jog.

We invited Derulo to come to our Men's Health office for a face-off with our fitness editor, Ebenezer Samuel, for a Celebrity Challenge. We put Derulo’s upper body strength to the test in three rounds of grueling no-weights moves. Check out the competition above.

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preview for Jason Derulo Men's Health Interview
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We also talked to Derulo about his fitness routines and goals. “I try to fool my body and always try to do something different because obviously your body gets used to the same routine over and over again," he said. (Here are a couple of tips on how to switch up a boring workout regime.)

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