Watching actor Chris Hemsworth’s biceps bulge as he smashes his Thor hammer is enough to grab moviegoers’ attention.

The image is also driving some men to pump enough iron to make their bodies just as muscular.

But how realistic is this desire?

pressure to be muscular

Not very, according to Hemsworth's body double, Bobby Holland Hanton, who was recently quoted saying he has to eat 35 times a day to get close to Hemsworth's size.

Experts agree that getting a physique like Hemsworth's requires extreme measures.

That sometimes causes bigorexia, a condition that occurs when a person constantly obsesses or worries about being too small, underdeveloped, or underweight.

"You have these actors on covers of magazine and being interviewed on TV, and a small group of men within the weightlifting community will take away a message that that's how they have to be. They will grossly overreact, buy a lot of supplements, and maybe experiment with illegal substances," Adam Bornstein, founder of Born Fitness, told Healthline.

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Like an Extreme Sport

While Bornstein doesn't believe bigorexia is a widespread problem, he says it happens especially in adolescents and teenagers who are more easily influenced by the media and marketing of so-called "superhero" workouts and diets.

Monica Reinagel, a licensed nutritionist who blogs at says while people can indeed look like Thor or Captain America, it's not consistent with optimal nutrition or health.

"Pursuing an extreme body ideal is a bit similar to people who do extreme sports or run ultra-marathons. It's possible. They prove it and do it, but they're at a point where they're no longer pursuing a fitness goal or health goal," Reinagel told Healthline.

Their intentions may include attracting attention or opportunities, or for psychological, emotional, or neurochemical payoffs, notes Reinagel.

"Running three miles is a realistic goal for increasing your health and fitness, but it's an error to think that running 100 miles makes you thirty-three times more healthy,” she said. “In fact, it's usually at the expense of health. The same can be said about bodybuilding. Those goals are often at the expense of other measures of health and wellness, such as skeletal health and joint health."

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Trend Comes and Goes

Bigorexia isn't a new trend.

Bornstein says it tends to rise when it's prevalent in mainstream media.

For instance, there was a spike in the late 1980s and early 1990s around the Arnold Schwarzenegger era, and again when steroids issues related to baseball stars Mark McGwire and Barry Bonds were in the media.

Each time the issue comes up; weightlifting tends to get a bad rap.

However, there are plenty of healthy lifting practices for the average person looking to add muscle and cut fat for the sake of health.

"Weight training is something you can do your entire life. The benefits from an anti-aging standpoint for joints and heart health for insulin — hormones that can protect your body from things like diabetes — are great," said Bornstein.

He suggests that most people aim to weight train three to four times a week and work all muscles of the body.

"A lot of people will go about it the wrong way and think they have to train six or seven times a week and work a different muscle each day. That's extremely time consuming and not the most efficient way to do it," he said.

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Don’t Forget Your Protein

Of course nutrition plays a part, too.

If you are exercising to lose weight, gain muscle or maintain it, it's important to consume sufficient protein so that you're not cannibalizing your own muscle tissues.

"When people are losing weight sometimes they're losing quite a bit of muscle tissue and that's not what we're trying to do. We want to lose fat tissue," said Reinagel. "The reason they're losing muscle is because they're not taking in enough protein."

She explains it like this. The exercises that you do to build muscle involve intentional muscle damage. You're breaking down muscle fibers on purpose so that when those muscle fibers grow back they grow back stronger and thicker.

"It's sort of a controlled and intentional process of restricting and rebuilding, but the rebuilding only happens if there's enough raw material there so it's also very important to make sure that protein is sufficient for muscle building," Reinagel explained.

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No Getting Past Genetics

No matter how well you eat and exercise in a healthy manner, keep in mind that

genetics also plays a role.

"It's not to say that you shouldn’t have big expectations for yourself, but those expectations should be based on you and your body and what you really think will make you happy," said Bornstein.

If you still want to look like Thor or Captain America, he offers some considerations.

"I know from working with models, actors, and athletes that many are genetically superior, so it's not something to feel bad about. For you to look at the workout that some person did and do that and then wonder why you don't look like them is a broke concept because the biggest variable in changing your body is personalized," said Bornstein. "People are going to react differently to exercise and nutrition. If you try out the workouts of these superhero actors and athletes, go in knowing that what works well for them might not work well for you."