There is a serious amount of pressure involved in becoming a superhero. Comic book fans are relentless in their assassination of 'unsuitably' cast actors. Only stellar performances will win over the scrupulous paying public. So imagine being cast not only as a superhero, but an intergalactic Norse god to boot?
Chris Hemsworth succeeded, and also sandwiched a stint as a womanizing, drug-abusing, 185-pound, 1970s race car driver between his two films in the role of Thor! That's a task even a genuine comic book crusader would have trouble with. Yet that is life for Hemsworth. In the past two years, his career has skipped into the Marvel universe, onto the racing track, and back again.
Chris shaped up to play Thor for the blockbuster "The Avengers," then slimmed down to become British Formula-1 world champion driver James Hunt for "Rush." Immediately afterward, he bulked right back up again to don the red cape and wield the mighty hammer of his alter ego for "Thor: The Dark World."
THE GOD OF THUNDER IS ONE OF THE STRONGEST CHARACTERS IN THE MARVEL UNIVERSE. TO PLAY THE PART, HEMSWORTH HAD TO PACK ON 30 POUNDS OF MUSCLE, TWICE.
We caught up with the Aussie action hero to find out exactly how he made his sudden transformations. Hemsworth detailed the incredible struggle he endured to cut weight for "Rush," and the strict high-protein diet that helped him pack the muscle back on again to return as Thor.
He revealed the alternating exercise regimens that transformed his training schedule not once, but twice in a short period of time. Also, look below to see his Mighty Mjolnir Workout. This is how you transform into a Norse god!

THE RUSH CUT

For athletes who cut weight for sports, the thought of dropping 30 pounds in four months isn't one they would relish; it certainly isn't a pleasant experience. Mentally, physically and emotionally draining, cutting weight is the toughest part of any athlete's training plan—ask any jockey or professional fighter.
Hemsworth's sporting background is based on catching waves atop a surfboard. He has little experience in the art of cutting weight and he was tasked with slicing 30 pounds off his 6-foot-four frame to play Formula 1 cult hero James Hunt in Ron Howard's "Rush." The transformation was a battle long before he entered the pits.
According to Hemsworth, the weight he shed was one of the most difficult things he's ever had to do for any of his previous acting roles. "The first thing Ron Howard said to me when I got the 'Rush' job was, 'I don't know if Thor is going to fit into a race car,'" Hemsworth recalls, chuckling at the memory. "I was filming 'The Avengers' when I got the call for 'Rush,' so I went from 215 pounds, which is how much I weigh when I'm playing Thor, down to about 185 pounds to be able to fit into the car. That was all in about four months."
"I immediately went from weightlifting into cardio training to shed that extra 30 pounds, which was a pretty nasty thing to do. I'd rather put on weight any time. I was basically underfed and overtrained for a number of months—and it was still a squeeze to get into the Formula 1 car."
Chris quickly put aside his weightlifting regimen and a new cardio-based training schedule took its place. Thus, Hemsworth had the conditioning aspect of his weight-cut firmly in place. As difficult as the constant cardio regimen was, Chris insists that living on a strict diet for four months before filming began was easily the more difficult task.

The real James Hunt

Hemsworth's cut to 185 pounds was commendable, but Formula-1 driver James Hunt actually weighed 175 pounds. Hunt (6-1) was three inches shorter than Hemsworth (6-4). No F1 driver has ever been as tall as the Aussie.
Hemsworth says: "I had to burn the muscle off and I had such a limited time in which to do it. It was pretty brutal. I was basically on a calorie deficit and I took away the heavy weights. I had to mainly get rid of muscle because I didn't really have much body fat on me after 'The Avengers.'"
"I ate very little protein and carbohydrates, lots of vegetables. And then I'd just run to sweat it off. I was filming 'The Avengers' when I got the call for 'Rush,' and so I sweated off the weight with a lot of running—long-distance running. It was a pretty moody existence to be honest, and I can imagine it was a moody existence for everyone around me."
"I drank a ton of water as well. I'd definitely recommend that to people who are cutting weigh. It fills you up ... to a degree. I got very scientific with the calories in and calories out." He adds with a laugh: "My wife was actually pregnant at the time of me cutting down for 'Rush' and I had more symptoms of a pregnant woman than she did. I was moody and hungry all the time, and I kind of immediately knew what it is like to be truly at the mercy of something. Honestly, food was the last thing I thought about before I went to bed and the first thing I thought about when I woke up."