"Chris is already huge, he's much bigger than me naturally so I have to train twice a day."
In addition to training, Hanton and Hemsworth have to eat eight meals every day when getting in shape to play Thor, even during filming.
"It's a job in itself," Hanton said about maintaining the physique required to play the character.
"We might train first thing in the morning and last thing at night. We try and eat every two-and-a-half hours. For breakfast we might have something like scrambled eggs with steak and spinach. No carbs in the morning. Then two hours later we might have a chicken breast and salad.
"After our first training session we'd introduce the carbs, usually brown rice, sweet potato or quinoa and then we'd continue to eat carbs up until the last meal. It's pretty intense."
It's an exhausting schedule of training, eating and working that former British gymnast Hanton has to do day in, day out when Hemsworth is making a movie.
"I've done a few Thor and Avengers movies now and generally it would be over a six-month period. But just recently we did Ragnarok, straight into Avengers 3 and Avengers 4, so it was staying in Thor shape for the best part of a year-and-a-half and that was the biggest challenge to date so far," he told news.com.au.
Hanton, who is in Australia to promote Band-Aid Advanced Healing, raved about Hemsworth and described the down-to-earth star as the "ballsiest" actor he's worked with.
"We're the same age, have the same kind of personality and we laugh at the same things," Hanton said.
"He's very loyal and keeps a really strong team around him and takes them around on each movie."
And when they finish making a movie together, Hanton revealed that Hemsworth has a very special way of saying thank you.
"Chris knows that I'm a big lover of watches so Chris is always buying me watches which is a bonus for sure," the stuntman said.
Hanton's list of films include Wonder Woman, The Dark Knight and Star Wars. He was also Daniel Craig's stuntman on the 2008 Bond movie, Quantum Of Solace, and had to do a stunt during the shooting of that movie that he still considers his most daunting to date.
"It was my first movie and I was just 23 years old, covering Daniel Craig as James Bond. For my first ever stunt on camera, I had to do a balcony jump at two in the morning in the slums of Panama," Hanton told news.com.au.
"There was no safety below, no cables or anything, it was a completely free jump in the dark. That is a standout one for me, even 10 years on."
And as you'd expect, he's had his fair share of injuries over the years.
"I sustained a pretty bad back injury on Green Lantern back in 2010," Hanton recalled.
"I ruptured and herniated my discs and that affected my sciatic nerve so that was pretty full-on.
"You get a lot of grazes and bruises, cuts and wounds all the time. Obviously I used Band-Aid Advanced Healing to combat that [seamless plug] and make sure I can get back to jumping around like a crazed idiot as quick as possible.
"We might do a fight scene 10 times when shooting and if you've got a cut, wearing a Band-Aid with the advanced cushioning almost acts like a pain barrier so you can carry on."