No, that wasn't Chris Hemsworth in that intense superhero fight in Thor. That was his super fit stunt double. Celebrity stunt doubles are the secret weapons to give action films their wow factor! Stunt doubles must train twice as hard as action stars to be their high-flying, ass-kicking counterparts. It takes a passion for exercise and a sense of fearlessness to have this kind of career. Most stunt doubles have backgrounds in marital arts or gymnastics which keep them in top psychical condition. Female stunt doubles have a tougher time then males as they are often made to perform the same daring fights, flights and fire walks in stilettos and skimpier clothing. Pictured below are celebs and their stunt doubles on the sets of hot action flicks: Zac Efron Snapped here is Zac Efron on the set of Dirty Grandpa with his stunt double. His double was tasked with doing handstand in place of buffed out Zac. Zac has also used a "butt double" for scenes that flash some crack. The Rock Dwayne Johnson and his identical double looking equally burly on the set of Pain and Gain. Megan Fox The sultry star discusses scenes with her stunt double on the set of blockbuster Teenage Mutant Ninja Turtles. Jennifer Aniston and Jason Sudeikis These Jen and Jason look-a-likes film a scene for We're The Millers while the real stars stay safely in their dressing rooms. Mila Kunis Mila and her double striding through a scene in The Angriest Man In Brooklyn, starring along side the late Robin Williams. She also used a double for her nude scene in "Friends with Benefits" with Justin Timberlake. Doubles from the Avengers Wouldn't it be awesome to have a real life stunt double that you could use for laundry, gardening hauling the groceries out of the car? You could even send them to the gym for you ;) What tasks would you assign to your body double?