Of all the actors who had to pack on mass for a movie, few in recent memory have taken to the task with such zeal, and notable success, as Chris Hemsworth when he landed the part of Thor.

For the first film, Hemsworth hit the gym with trainer and former Navy SEAL Duffy Gaver, who applied an old-school bodybuilding approach—with careful attention given to Hemsworth’s arms and shoulders. Thor, after all, often appears sleeveless, but rarely shirtless. All told, Hemsworth gained 20 pounds, laying the foundation for a physique he’s maintained at or close to peak condition for Thor’s recurring role in The Avengers and the solo sequel, Thor: The Dark World.

Hemsworth was a model of consistency, and the physique he built has made “Chris Hemsworth Workout” the top search suggestion when you punch the actor’s name into Google.

“People see Chris and they think he was on steroids, but he didn’t touch a single substance,” Gaver says. “It was just red meat, heavy weights and some protein powder. He crushed every single workout. He simply decided to look like Thor.”