The hallmark of the average superhero is the above-average form they possess. As Stan Lee wrote in the classic How to Draw Comics the Marvel Way with John Buscema, "A superhero simply has to look more impressive, more dramatic, more imposing than an average guy." When superheroes move from the printed page to the silver screen, however, flesh-and-blood actors fill out their forms. Unfortunately for them, fantastic means such as cosmic radiation or mystical potions aren't available to turn thespians into powerhouses, and an artist's pencil and an inker's brush can't build up their biceps and triceps.

No, actors have to work at their fitness, and work they do. There are numerous ways to do it: following the advice and plans of nutritionists, intense sessions with trainers, varied martial arts. There are methods like plyometrics and Pilates, which use science to study the body and how it moves in order to get faster, more effective results. And there's tried and true weightlifting with barbells and dumbbells. Our actors here have tried all of these things and more, in various combinations, to stunning effect. Here are 16 things you have to do to get a superhero body, according to Marvel Cinematic Universe stars.

16 CHRIS HEMSWORTH -- OLD-SCHOOL TRAINING

Standing 6 feet 3 inches tall, Chris Hemsworth towers over most of his cohorts in the Thor series and the Avengers films. As the titular demigod, Hemsworth has to look the part, and he does, thanks to workouts with trainer Duffy Gaver, a former Navy SEAL. Gaver told Men's Fitness that they went with "old-school training" -- pull-ups, rows, squats, presses and the like -- which bulked up Hemsworth by 20 pounds for 2011's Thor. As Thor often sports bare, brawny arms, Hemsworth's training zeroed in on those and his shoulders.

But Hemsworth learned that weightlifting alone wasn't suitable, so he varied his approach, adding yoga and other flexible training. "I was, I think, probably a little bigger the first time around, but I felt very stiff and uncomfortable," he told W magazine. "Now, I feel much more, like it's useful kind of muscle, functional kind of movement and training."

15 CHADWICK BOSEMAN -- CAPOEIRA

In the 2018 film Black Panther, the title character gains power and enhanced senses and reflexes from ingesting a drink made from a special, rare plant -- the Heart-Shaped Herb. But the rippling physique actor Chadwick Boseman sports on the March 8, 2018 cover of Rolling Stone doesn't come from any potion, but from hard work.

On Instagram, Boseman posted a short video of himself training with Marrese Crump, captioned: "The purpose of training is to tighten up the slack, toughen the body and polish the spirit - Morihel Ushiba." Crump told Men's Fitness magazine that Boseman incorporated Muay Thay, Filipino martial arts, Capoeira and other disciplines in his training. "There are a lot of action movies that relegate to one certain style, and all of the fights look the same. Because of who T'Challa is -- a master of many -- we couldn't do that," Crump said.

14 CHRIS EVANS -- PLYOMETRICS

Thanks to the Super-Soldier Serum and additional treatments, Captain America represents the peak of human perfection. But before all that, he was the epitome of the 98-pound weakling, although one with a patriotic spirit. For the early scenes in 2011's Captain America: The First Avenger, Chris Evans was turned into a well-meaning wimp through digital work from Lola Visual Effects and stand-in Leander Deeny.

But once Steve Rogers was fully transformed into the Star-Spangled Sentinel, it was all Evans on screen. His training called for weightlifting to build up bulk, but also plyometrics, gymnastics and bodyweight exercises to maintain agility. "I've always liked going to the gym, but these weren't normal gym sessions. I was puking at the gym. They were brutal, absolutely brutal," he told Fitness & Power magazine.

13 TOM HOLLAND -- ELECTRONIC MUSCLE STIMULATION

Cast as the new Spider-Man in 2016's Captain America: Civil War and 2017's Spider-Man: Homecoming, Tom Holland tackled the assignment with relish. He indulged in daily workouts incorporating gymnastics, tumbling, boxing, breakdancing -- even hitting big heavy tires -- and posted his progress on his Instagram account. Holland also applied Electronic Muscle Stimulation.

His trainer, Ben Brown, describes EMS to Men's Journal: "You are strapped into a suit that covers all of the major muscle groups in your arms, legs and full torso. The machine has the ability to focus on specific body parts, and it sends pulses that contract those muscles 89 times per second. So it can feel pretty intense," but gets easier with repeated treatments. Holland put it differently, with a laugh: "It is 20 minutes of absolute hell."

12 MARK RUFFALO -- CGI, THE CLEANSE

The Incredible Hulk is 1,000 pounds of muscle and anger, concocted for the screen by the tech wizards at Industrial Light and Magic, which got 2012's The Avengers an Oscar nomination for Best Achievement in Visual Effects. But his portrayer, Mark Ruffalo, was diligent at getting alter ego Bruce Banner into shape, too.

In an interview with Paste magazine, Ruffalo says Banner would live "this really clean life in order to stay on top of his rage." Accordingly, "I did 21 days of this diet and it was one meal a day, two shakes, no dairy, no meat, no caffeine, no sugar no love no fun no sex no drugs no wine no women. I have to say the first week I had to lock myself away from my family so I didn't kill somebody, but then after that I started to feel really good."

11 SCARLETT JOHANNSON -- BREASTFEEDING

Scarlett Johannson is always busy. To get ready to play the Black Widow in Iron Man 2 and The Avengers, Johannson went for intense, 90-minute full-body workouts to make the most of her time. "A lot of it is endurance, stability and strength training. I like to work up a sweat," she told Barbara Walters in 10 Most Fascinating People of 2014 special on ABC.

But after the birth of her daughter Rose Dorothy, Johannson touted another method. "Breastfeeding is the best way to get back in shape. I do the whole bit. I'm nursing and I love it," she said. But the key is maintenance: "Once I get into a routine of going to the gym every day when I'm working, it's easy for me to just keep going. It makes me feel good. But once I start to slack, it's so hard to go back."

10 ROBERT DOWNEY JR. -- WING CHUN

Robert Downey Jr. came on the scene in the 1980s and '90s as one of the most promising young actors of his generation; early accolades include a Best Actor Oscar nomination for 1992's Chaplin. But struggles with substance abuse derailed his career and put him in legal jeopardy. In 2003, Downey turned to the Kung fu martial art Wing Chun to learn focus and stability. Bruce Lee studied the art as a teenager.

Cast as Tony Stark in 2008's Iron Man, Downey added bulk through weight lifting along with Wing Chun. That film's success along with Tropic Thunder the same year put Downey back on Hollywood's A-list. His work ethic and commitment to fitness carried through other roles. Preparing for The Avengers, which put Downey alongside Chris Hemsworth and Chris Evans, Downey told Men's Fitness, "I'm not particularly tall, strong, fast or aggressive. But I'm not faking it."

9 DANAI GURIRA -- SWORDPLAY

Danai Gurira, who stars as Okoye in Black Panther, would seem to never have a moment to breathe. Apart from her role in the 2018 Marvel blockbuster, she is an award-winning playwright, activist and acting teacher. And she's won rave reivews as the katana-wielding zombie slayer Michonne in AMC's The Walking Dead. But, as she told Shape magazine, "There's always enough time in the day to get in a 20-minute workout."

Gurira keeps fit with cross-training, Jillian Michaels DVDs, Pilates and sword practice, which she's done since her days at New York University, prepping for Shakespeare plays. But even for Black Panther, she needed practice. On Popcorn with Peter Travers, Gurira told of "dropping the staff 15,000 times," annoying her downstairs neighbor, who confronted her. "'I don't want it to hit the floor,'" she told the neighbor. "'So I'm really working hard to make sure you don't hear it.'"

8 CHRIS PRATT -- NO BEER

Chris Pratt parlayed a one-shot appearance as lovable lug Andy Dwyer on NBC's 2009-2015 sitcom Parks and Recreation into full cast status. Pratt  figured his success on the show was linked to his size, and gladly pigged out until he approached 300 pounds, he told Men's Health magazine. This nearly cost him a role in 2011's Moneyball, but he aggressively worked out and lost "35 pounds in six weeks."

For 2014's Guardians of the Galaxy, he got even more serious about shedding flab. He worked with a nutritionist, drank lots of water, and went for varied workouts, which paid off; he lost 60 pounds in six months. Pratt cracked the Internet with a selfie posted on Instragram, captioned "Six months no beer. #GOTG Kinda douchey to post this but my brother made me."

7 PAUL RUDD -- THE CHRIS PRATT APPROACH

Paul Rudd has an everyman, guy-next-door appeal that made him a natural fit for 2015's Ant-Man as ex-burglar Scott Lang. And although he was in okay shape for an average guy, he needed to kick things up a notch to be an on-screen superhero. Rudd told Variety, "I basically didn't eat anything for about a year. I took the Chris Pratt approach to training for an action movie. Eliminate anything fun for a year and then you can play a hero."

The diet was augmented with strength training and gymnastics. Co-star Michael Douglas said to MTV News, "He was so cut, that they had to soften his costume up, with all the built-in six-packs and all of that." Indeed, Rudd's torso is so cut, his abs have their own Twitter account: @PaulRuddsAbs.

6 ZOË SALDANA -- CLEAN EATING

Zoë Saldana, Gamora in the Guardians of the Galaxy films and the new Uhura in Star Trek series, advocates clean eating. She has Hashimoto's thyroiditis, an autoimmune disease that keeps the thyroid gland inflamed, always reacting to a non-existent infection. To compensate, Saldana eats a dairy- and gluten-free diet. According to her trainer, Steve Moyer, Saldana's workouts emphasize "staying lean and strong."

Saldana does power yoga, cardio and Pilates, going for 20- to 30-minute interval workouts that incorporate running and kettlebells. But to her, the key is balance. "I can't work out regularly, so I compensate by eating a lot healthier than I might otherwise," Saldana told Shape magazine. "Once you have relatively healthy eating habits, your workout can become playing with your kids, strolling around the neighborhood, playing airplane or just changing diapers."

5 PAUL BETTANY -- WORKING THE CORE

Paul Bettany got ripped to play the archangel Michael in 2010's Legion, with interval circuit training and core exercises. His next role, as Charles Darwin in Creation, called for a different approach: willfully getting out of shape. "For two, three weeks, just eating whatever I wanted all day long was just fantastic," he told Men's Fitness, but then it became a "slog." In 2015's Avengers: Age of Ultron, Bettany suited up as The Vision after being offscreen as the voice of Jarvis in the Iron Man films and The Avengers. That meant, "You go to the gym and you lift heavy things and you don't eat carbs, and that's really it," he told Ask Men. "I'm helped enormously by the costume, but it's very thin. It would be no good being all 'yoked' -- as I think they say now -- up, and then have this quite a beer belly."

4 DON CHEADLE -- WATCH THOSE CALORIES

From his first scene, Don Cheadle commanded the screen as Air Force Lt. Col. James Rhodes in 2010's Iron Man 2. Rhodes became the armored superhero War Machine, but Cheadle still needed to measure up to his non-armored co-stars. As he told WebMD, "You do have to get in shape for superhero movies, but I was lucky. I've had a lot of roles that I had to hit the gym for, so I already knew my way around the weights."

Cheadle also does circuit training, biking and Pilates, the better to keep him ready for his stunt work. But he told AskMen, "It's mostly diet -- unless you're training like an Olympic athlete, unless you're really putting in like six or seven hours a day, the most results you're going to see are in your caloric intake. Make sure you're controlling that." Accordingly, he doesn't drink soda.

3 DAVE BAUTISTA -- WEIGHT TRAINING

Size always mattered to Dave Bautista, who followed careers as a champion wrestler with World Wrestling Federation/World Wrestling Entertainment and as a mixed-martial artist with forays into acting. Drax the Destroyer in 2014's Guardians of the Galaxy and its sequel, he has to look his best. "With Drax always being shirtless, there's no room to hide any fat. I really focused on being in better shape and more muscular," he told Muscle & Fitness.

But he had to avoid getting too big. Bautista told Men's Health, "When I was with WWE, I was doing a lot more weight training. It was a different look because I had a different character. For film roles, and life in general, I've switched to a more cardio-based workout routine." Between roles, Bautista's routine includes boxing, cross training and grappling, three days on and one day off.

2 JEREMY RENNER -- MUSIC

Jeremy Renner is one of those actors who took 15 years to reach overnight success. But he's on the map, with appearances in The Hurt Locker, The Bourne Legacy and the Avengers films as Hawkeye. Of course, Renner learned archery, training with Olympic athletes, but he also determined when to use it and when to ignore it. "Real archery is not superhero Hawkeye archery. So [the training] kind of helped but it kind of got in the way, as well," he told an audience at the Silicon Valley Comic Con in 2016.

After all, Hawkeye indulges in hand-to-hand fights, so his bow is sometimes a blunt instrument. But Renner also gets his mind right for performing, too. "I make a playlist for every character I play," he said. "Music can transport you into a mood or place of mind that you need to be in. I love music for that."

1 SAMUEL L. JACKSON -- SOBRIETY, GOLF

As Nick Fury, Samuel L. Jackson is the connective tissue of the Marvel Cinematic Universe and a powerhouse at the box office. Box Office Mojo lists him as the world's highest-grossing actor with total grosses of $5.149 billion over more than 100 films. Jackson has been open about his past addictions to cocaine and marijuana, noting that he didn't let those interfere with his ability to perform on Broadway.

But one day in 1991, his wife, LaTanya Richardson, and their daughter, Zoë, then 8 years old, found him at home passed out while cooking a batch of crack cocaine. From there, Jackson went to rehab, and has remained sober since. These days, he gets his recreation on the golf course; in his film contracts, he stipulates he must have time to hit the links.