2023 was a massive year for big, testosterone-fuelled flicks, but The Iron Claw–and Zac Efron in particular–is ready to outmuscle them all. Directed by Sean Durkin (who made 2020’s brilliant The Nest), Efron takes on the role of real-life wrestler Kevin Von Erich, with The Bear’s Jeremy Allen White and Triangle of Sadness’s Harris Dickinson playing his brothers as they each try to climb to the pinnacle of a professional wrestling industry on the cusp of its ’80s Golden Era.
Based on the talent involved, The Iron Claw is undoubtedly a thought-provoking film about much more than muscles–but here, it's the muscles we’re interested in, particularly with the leading man who got into outrageous shape. But drastic body transformations aren’t as clear cut as "lift heavy weights, feel good": Efron has said previous transformations of his weren’t really attainable for the average person and have even left him depressed.
With that in mind, we asked PT Farren Morgan, founder of The Tactical Athlete training method, to talk us through the incredible amount of work Zac Efron put in and how–if you really must copy him–you can do it safely.
How did Zac Efron transform his body for The Iron Claw?
Going from ripped, muscular guy to absolutely jacked wrestler means one thing: bulking.
“Bulking is a widely used term in fitness for those that have decided to increase their caloric intake and combine this calorie surplus with intensive weight training to increase their muscle mass and strength,” explains Morgan.
In layman’s terms, upping the fuel you take in helps provide energy to lift heavier weights, creating larger muscles that use this fuel to repair and grow–a highly effective process.
However, it isn’t quite as simple as eating a lot and lifting heavy. That will get you jacked, but you won’t be ripped. “Bulking is only the first of three phases,” says Morgan. “If you decide to begin bulking, you will have to follow through with the second phase, known as cutting, to decrease the body's fat levels, and the third phase known as maintenance, to retain your muscle growth and provide adequate time for your body to adapt to your muscle growth and physical transformation.”
In other words, getting in shape and staying in shape through filming is a hell of a lot of work. Not to mention chicken breasts. Which brings us to…
How much do I need to be eating to look like that?
Food intake differs for each person, but to optimize muscle growth and maintain a healthy balance, you should generally aim to consume a slightly higher number of calories than your body needs to function during the day. “You should consume a maximum of 20 percent more calories than your body needs per day to increase your weight gain by roughly half a percent of your body weight each week,” explains Morgan.
For men, this means around 2,750 calories per day to help you bulk safely and effectively. With that word, “safety” in mind, we don’t recommend the dirty bulk, either, when you eat anything and everything to get the required calories in. It’s much better to eat cleanly, where you can control the levels of nutrients, salts, fats, and otherwise limit things like sugar.
“After you’ve established the goal for your caloric intake, you’ll need to split the calories you consume by their macronutrients: proteins, carbs, and fats,” says Morgan. “Aim for your diet to consist of 30 to 35 percent protein, 45 to 60 percent carbs, and 15 to 30 percent fats.”
For men, you’re looking at 207 to 241 grams of protein, 310 to 413 grams of carbs, and 46 to 92 grams of fat during the bulking phase.
Why do I need to be careful?
Let’s be honest: There isn’t really any need to bulk up to this degree. Outside of acting and professional bodybuilding, there’s no practical reason to add so much weight to your frame. And every time you do, you put your body under immense strain, the results of which could be catastrophic.
We probably don't need to tell you to avoid steroids and performance enhancers (all of which have a chequered history of health complications), but just because you’re following the protocols laid out here, it doesn’t mean bulking up is without risk.
“Drastically scaling the intensity of your training beyond the capabilities of your muscles will increase your risk of injury,” explains Morgan. “On the diet side, dirty bulking can cause significant side effects such as unwanted fat gain, high cholesterol, blood sugar, and blood pressure, stroke, diabetes, and cancer, which is why it’s vital to bulk safely and effectively for the sake of your health and wellbeing.”
To avoid these mistakes, Morgan stresses that it’s important not to rush and to understand that muscle growth is a process that takes time. “Lean individuals who have difficulty gaining weight should aim to gain a half to one pound per week, while heavier individuals should aim to gain one to two pounds per week,” says Morgan, who goes on to explain that hitting your macronutrients is the best way to ensure you’re on track.
What else do I need to think about?
When you’re pushing your body this hard, recovery and sleep are just as important as diet and training, if not more so. “While you sleep, your body releases protein-building amino acids at an increased rate, which is crucial for anyone looking to develop bigger and stronger muscle,” explains Morgan. “Zac would need to get at least seven hours of sleep to optimize his muscular hypertrophy.”
Martin Sharp, fitness coach, and award-winning personal trainer agrees that missing out on your forty winks could have negative effects on your bodybuilding and general health. “Without the time for good quality sleep, your body doesn’t have the necessary time to make its repairs, including adaptations such as building muscle,” says Sharp. “The lack of sleep can [also] be a catabolic stressor, breaking down many of the hard-earned gains that you have created.”
Efe Obada of the NFL's Washington Commanders told GQ just how vital sleep is for recovery at the top of sport. “Sleep is probably one of the biggest things. It is everything,” said Obada. “You can work out until your body's mashed up and you think you need a whole year of rest – you have one good sleep, I'm telling you, it makes a huge difference.” Six Nations star Maro Itoje agrees: “Sleep is the number one recovery method. The benefits of a good sleep trounce all other forms of recovery… it gives you that mental recovery, it gives your body time for muscle repair, and your body is in a deep state of relaxation.”
Is there a Zac Efron bulking workout I can try?
“As a wrestler, Zac would need to focus on bulking workouts to optimize his strength and mobility training so that he remains fast and agile,” Morgan explains. “With this in mind, some excellent workouts to try out as you bulk would be overhead squats , pull-ups, back extensions, weighted leg raises, and the incline bench press.”
Aim to perform three sets of six reps, gradually working your way up to five sets of 10 reps when that becomes easy:
1. Overhead Squat
2. Pull Up
3. Back Extension
4. Weighted Leg Raise
5. Incline Bench Press
How to do each movement:
1. Overhead Squat
Hold a weighted barbell overhead, your arms fully extended in a ‘V’ shape. Keeping your back and arms still, head forward, and hinge at the hips to sit back onto an imaginary chair. Push through your heels to straighten up for one.
2. Pull Up
Grip an overhead bar with your hands facing forward, slightly wider than your shoulders. Engage your shoulder blades as you pull your chin up and over the bar. Hold, and slowly lower yourself back down. Hang with arms extended for a second, then repeat.
3. Back Extension
You’ll need a back extension bench for this one, and a weight plate. Stand in the equipment, holding the weight to your chest. Lean forward so your body makes an inverted ‘V’ shape, then slowly raise yourself back to near-vertical. If you feel pain in your lower back, ditch the weight immediately and stretch out on a mat before continuing.
4. Weighted Leg Raise
You can do this lying on your back with a dumbbell between your feet, but a much safer way is to use the leg raise machine. Choose a weight slightly lighter than you think you can handle to warm up, extending your legs and then slowly lowering them as you work your way to a heavier weight through your sets.
5. Incline Bench Press
Set the bench so you’re closer to sitting up than lying flat, and take a dumbbell in each hand. Starting with the weights at chest height, extend your arms to power them overhead. There’s no need to clap them together in the middle. Slowly lower the weights for one rep, feeling the work at the top of your chest.
Congratulations! You're on your way to wrestling stardom – or a new wardrobe, at least.