In 'Hot Frosty' and 'The Merry Gentlemen,' abs take center stage. Secrets behind the actors' six-packs.

Cozy sweaters may be all the rage in most holiday movies, but Netflix’s new Christmas movies have a different aesthetic — and that aesthetic is abs. In Netflix’s The Merry Gentlemen, a woman (Britt Robertson) returns to her hometown to save the local bar — with the help of an all-male, shirtless dance revue featuring her very buff love interest, played by Chad Michael Murray. (The actor even did a steamy holiday calendar to promote the movie.) Meanwhile, the streamer’s Hot Frosty sees a snowman come to life in the form of an ab-baring Dustin Milligan of Schitt’s Creek and 90210 fame.

Abs have long been the aspirational marker of male fitness — consider Brad Pitt’s rock-hard body in Fight Club, or Michael B. Jordan's shredded physique in Creed. Now that six-packs are front and center this holiday season, it’s worth wondering … how the heck does one even get that ripped?

Yahoo Life went straight to the source: Colt Prattes, one of the titular (and toned) Merry Gentlemen in Netflix’s latest holiday hit. Prattes, who is currently performing in Aladdin on Broadway, has a background in personal training, fitness modeling and bodybuilding competitions. So, what’s his secret?

“I followed this program called P.H.A.T. — it's literally lifting really heavy two days a week, taking a break and then lifting for hypertrophy, or muscle gain, for three days a week, and then taking two days off,” he tells Yahoo Life over the phone. “It works out perfectly with my show schedule, because then on two show days, I don't have to worry about going to the gym,” he says.

Lifting heavy typically means using extra-heavy weights with fewer repetitions, aiming to build strength and improve overall lifting capacity. In contrast, lifting for hypertrophy involves using moderate-to-heavy weights with more repetitions, focusing on increasing muscle size by creating micro-tears in the muscle fibers, which repair and grow larger over time.

Prattes adds that he can maintain his lean, muscular look by hitting the gym a few times a week (in addition, of course, to all of the cardio that comes with dancing on a Broadway stage for six shows a week). But he has also spent two decades getting his body where he wants it to be.

“For a lot of years, I was in the gym six, seven days a week, and I’d only take off when I’d have to,” Prattes says, noting that, diet-wise, he was eating “a ton” of what he now considers to be “unnecessary” protein. “Now I’m in the gym three or four times a week. It’s like any other skill — once you put in that work your body's like, ‘Hey, I don't want to do this either. Let’s chill.’ And then you can kind of coast.”

In terms of his abs, he says he credits his dad, who was in “better shape” than he had ever been in. “He would do weighted crunches for his upper abs — ‘zombie crunches’ with a weighted 45-pound plate. … I remember his abs were always huge and blocky,” Prattes says. “So I did that for a little bit so I could get some size on my abs, so if I wanted to get a little more fluffy, I would still have some size in there.”

When he wants his abs to pop, he focuses more on leaning out his diet. Reducing body fat means you may be able to see your muscles more — but you have to have muscles underneath in the first place. “I think of it like, if you're going to vacuum-seal a bag, then you have to put stuff in it first. Otherwise, you just get a crinkled-up bag,” he says.

His regimen is working — so much so that Murray, his co-star, turned to him for an at-home workout routine. And while Prattes may be viewed as the prototype for many people looking to achieve that cut look, he says that his “focus is more on being healthy” than on aesthetics.

“I value health over that, so I'm not going to do something that's going to shut my body down and cause me to be in this awful caloric deficit,” he says. “I'm going to try and stay ready so I don't have to suddenly get ready [to look good].”

What do fitness experts say about abs?

Jake Dickson, a personal trainer and weightlifting coach for BarBend, tells Yahoo Life that the key to seeing abs comes down to body composition. “If you have low body fat levels but no muscle, hitting the gym with a proper routine becomes as, if not more, important than your diet. Beginners who have no experience with strength training can build muscle even without changing their diet,” he says.

On the other hand, Dickson notes that if you’re carrying more body fat than you’d like, diet is crucial. “This is also true for jacked actors who need to ‘cut up’ for a role, which entails following a very low-calorie diet while also performing plenty of cardio to melt away body fat and shed water weight.”

Fredrick Hahn, trainer and owner of NYC-area fitness studio SlowBurn, recommends a diet that consists of “adequate protein,” as many people who are resistance training “don’t eat enough throughout the day.” While Hahn, who prefers animal protein, recommends about one gram of protein per pound of your ideal body weight, research is mixed on what’s appropriate. The International Society of Sports Nutrition (ISSN) recommends 1.4-2 grams of protein per kilogram of body weight per day.

Why you may not achieve the same look as your favorite actors

It’s important to know that genetics and body type play a role in how you look — even if you’re working out and dieting. Some people may be able to have muscles that pop more easily than others, given where fat sits on their body.

Bradford Stevens, founding instructor at Sole+ Studios, tells Yahoo Life that patience is crucial when it comes to laying the groundwork for eye-catching abs. Stevens notes that healthy weight loss is typically just 1 to 2 pounds per week, and that building muscle can take even longer to achieve.

“It’s better to start with a sustainable routine and work incrementally toward your goal,” he says. “Could you make noticeable changes in less than a month? Sure. Should you? Probably not. Consistency and patience will get you better results in the long run.”

It’s also important to know that people who are taking their shirts off in movies are paid to look a certain way and often have the time and resources to work out and diet so that they can appear extra ripped onscreen. Stevens points out that “comparing yourself to others is a recipe for frustration” when you are on a fitness journey. “Not everyone’s body is built to look like a Hollywood action star, and that’s OK,” he says.

What’s more, some onscreen bodies only look a certain way because of movie magic — or even unhealthy approaches. Zac Efron, for example, previously shared that he took “powerful diuretics” — which help eliminate water from the body — to achieve a lean lifeguard physique for the movie Baywatch.

“Bodybuilders undergo ‘water cuts,’ involving multiple days of manipulating their hydration, to shed the excess water stored in their bodies,” Dickson explains, adding that “holding water” can make someone look softer rather than more trim. Actors often do the same thing, he says, to achieve a certain look in the hours leading up to filming a shirtless scene. “Forcibly dehydrating your body is a common practice in certain sports, but it does pose health risks ranging from lightheadedness to kidney failure,” he says.

The bottom line

Some of the work required to get abs can be good for your overall health, such as prioritizing movement and watching your protein intake while cutting back on excess calories from carbs and sugar. However, it’s important to make sure you’re still meeting all your nutritional needs, not overdoing your workouts and being realistic about your body expectations. Taking diuretics or not drinking enough water can harm your body, and experts advise against it.

“It certainly is healthy to have low body fat and good lean body mass — but it depends upon how you arrive there,” Hahn says. “It’s the journey, not the destination.”