Nick Jonas has made one hell of a career transformation over the years—and it's clear he's been hitting the gym to do it.

From his early days as a Jonas Brother to his solo musical career that helped make him a worldwide pop-culture icon, Jonas has proven he's an adept chameleon in the spotlight. Now, he's parlayed that white-hot superstardom—and his six-pack abs—into a successful acting career and a rightful place as one of the fittest actors in Hollywood. With roles in the mixed martial arts show Kingdom and the blockbuster film Jumanji, Jonas has proved he can slug it out with the baddest brawlers around—and hold his own alongside titans like Kevin Hart and Dwayne "The Rock" Johnson.

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But all that muscle isn't just for show. Here’s a look at Jonas’ toughest physical roles—and a glimpse at where he might go next.