Chris Hemsworth first pushed his limits at age seven, while living in an Aboriginal community in the bush north of Melbourne, Australia. He was the rare white child, there because his parents herded buffalo and ran the local food store, which doubled as the post office. “We’d heard many aboriginal spiritual beliefs about things. We’d been told there was a cave nearby that had spirits in it,” he says.

What’s a kid to do? This, naturally: “We built wooden swords and hammered nails into them, and we checked out the cave. my friends and I were convinced we’d meet some ghosts and devils.” all they found were craggy walls that echoed their deep breaths. Hemsworth still dives into places that challenge him – but now, 20 years later, those spots are more likely to resemble the farmers’ market where we’ve come to walk around. it’s the sort of place that was crucial for a man who had to pack 10 kilos of muscle onto his 1.9m frame so he could play the lead in the upcoming movie Thor. Adding that much weight required a constant intake of food, most of which came from protein sources, vegetables and fruit. “I feel as if I’ve been busy, but all I’ve been doing is eating all day,” he says as we pass a farm stand brimming with organic broccoli. “Eating when you’re not hungry and taking in that amount of food is exhausting.”

But every bite was useful, because you can’t rely on just protein shakes to help you grow. Sure, protein was Hemsworth’s foundation. But non-processed carbohydrates, such as fruit, helped him rebuild muscle by slowing muscle protein breakdown. Fruits and vegetables provide fibre, which can strengthen cardiovascular health, and their antioxidants aid muscle recovery. He was strategic, eating for value. For example, he didn’t bother with rice but scarfed quinoa. “It’s one of the few grains that actually has protein,” he says. It also has healthy fats and fewer carbohydrates than most grains. Food was only a third of the equation. “Rest and exercise were equally as important,” he says.

Sounds sensible enough. And it’s a formula anyone can follow. Need proof? “It wasn’t until Thor that I started lifting weights. It was all pretty new to me,” he says. Before that, he’d built a foundation of fitness purely by playing sports. He surfed as if it were his religion; he boxed; and he even played Aussie Rules – the sport that’s like the over stimulated love child of soccer and rugby. But when he hit the gym, he needed to build dense muscle that would show onscreen. That meant dedicating himself to a regimen that incorporated ever-changing challenges. His trainers constantly forced him to vary weight, reps and even speed so that his muscles never adjusted to workouts. Even minor changes, such as swopping hand placement on a pull-up, can stimulate muscles in new ways. In fact, mixing things up is important no matter what kind of muscle gain you’re looking for. When your usual workout starts to feel easier, it isn’t benefiting you as much as it once did.

If you visit the gym regularly, eat right and rest enough, how quickly will you see results? Consider this: Hemsworth trained hard for Thor while filming Red Dawn, a movie due for release later this year. If you watch that film closely enough, you will actually see the size of his neck change from scene to scene. (Who smells DVD bonus material?) These days, with filming over, Hemsworth has dialled back the gym visits – but he hasn’t left them entirely, and he’s playing plenty of sports. After all, for any sequels he’d have to retain his size – which would disappear quickly if he didn’t stay active and eat enough. He learnt that the hard way, when he shrunk after only a four-week vacation. “My body doesn’t sit at that weight,” he says. But with enough work, it will.

The God of Thunder Workout
After bulking up for the role, Chris Hemsworth was too big for his Thor costume. So he ate less and did metabolic circuits to burn kilojoules without sacrificing muscle. A few weeks later, he was the right size – and still looked big. You too can focus on muscle definition, not just size, with this Thor-inspired workout from strength and conditioning coach Eric Cressey.

Do this
Perform this circuit, rest 60 seconds and repeat three more times.

Sledgehammer slam
8 reps each side
Stand about 30cm from a tyre, knees slightly bent. Rotate your upper back slightly to the right and raise a sledge above your right side. (Don’t rotate your hips.) Brace your abs and swing the hammer down; aim for the tyre’s inside edge. Do all reps and switch sides.

Lateral hop
8 reps each side
Stand with your chest up and hips back. Dip your knees slightly; explosively hop off your left leg and move horizontally to your right. Land on your right foot and “stick” the landing so your body stops moving. Pause, then immediately hop back off your right leg, landing on your left.

T push-up
8 reps each side
assume a push-up position with your hands on hex dumbbells. Lower your body to the floor and as you push yourself back up, rotate the right side of your body upwards as you pull the right dumbbell towards your torso. Now straighten your arm so the dumbbell is above your right shoulder. Lower the dumbbell and repeat on your left side.

Mountain climber
15 reps each leg
assume a push-up position, making sure your arms are straight. Lift your right foot off the floor and slowly raise your knee as close to your chest as you can. Touch the floor with your right foot. Return to the starting position. Repeat with your left leg. That’s one rep.

The power of the hammer Thor’s weapon of choice is his hammer, which is fitting: it’s one of the best home workout tools. “Sledgehammer swings are not only an incredible way to improve your upper-back mobility and core stability, but they also add upper-body power,” says strength coach Eric Cressey.

What’s more, if your legs are shot at the end of a workout, these offer a perfect cardio alternative to crank up your heart rate and pound away extra kilojoules. If you don’t have a tyre or a sledgehammer, you can reap similar benefits by doing overhead medicine ball slams.

How Chris Hemsworth Ate to Grow

1 Pack protein
To put on size, Hemsworth ate more protein than he usually did. The reason: he was eating for the body he wanted, not the body he had. Every day, try to eat one gram of protein per half a kilo of your goal weight.

2 Eat with awareness
Changing your diet isn’t easy. Hemsworth was told to remind himself of what each meal was doing for his health. “I ask myself, ‘Why am I eating this chicken? For protein. Why am I eating this broccoli? For vitamins and fibre. Why am I eating this Twinkie?’” (Yeah, why are you eating that Twinkie?)

3 Go red
Lean protein is great, but don’t give up on steak. “It’s a dense source of protein and helps your muscles repair,” says one of Hemsworth’s trainers, Duffy Gaver. A trimmed 85g cut packs 27g of protein, as well as B vitamins, zinc and iron – all of which can help you grow.

4 Fuel your workouts
Hemsworth made the most of his workouts by eating before and after them. Drink a protein shake within an hour of training, or eat a solid full-size meal up to two hours before you hit the gym, says nutritionist Alan Aragon. Within an hour after the workout, eat or drink the same amount.