--- title: 'Why Some Guys Build Muscle 3x Faster (And How You Can Too)' source: 'https://youtube.com/watch?v=eoqRWHZkS0c' video_id: 'eoqRWHZkS0c' date: 2026-07-22 duration_sec: 956 channel: 'Jeremy Ethier' --- # Why Some Guys Build Muscle 3x Faster (And How You Can Too) > Source: [Why Some Guys Build Muscle 3x Faster (And How You Can Too)](https://youtube.com/watch?v=eoqRWHZkS0c) ## Summary This video explores why some individuals build muscle significantly faster than others, even with identical training. It breaks down the genetic factors influencing muscle growth speed, potential, and limits, and provides actionable strategies to overcome genetic disadvantages. ### Key Points - **Three Types of Responders** [02:03] — A 2016 study with 287 people doing the same workout for 6 months identified hyper responders (2-3x faster, up to 30% growth), average responders (5-10% growth), and low responders (minimal or negative growth). - **Myostatin's Role** [03:04] — Myostatin is a protein that limits muscle growth. A rare mutation can disable it, leading to extreme muscle development, as seen in a German newborn and natural bodybuilder Paul Durand. - **Training Volume Strategy** [06:40] — Dr. Eric Helms' research suggests low responders can match high responders by increasing training volume. If doing under 12 sets per muscle per week, bump up by 20-30%. For 12-20 sets, gains are smaller; above 20 sets, more volume may not help. - **Specialization for Visual Impact** [08:42] — Focus volume on weak points (e.g., shoulders for V-taper) while maintaining other muscles with minimal sets. Start focus muscles at 10 sets/week, increase to 20-30, and reduce others to 4-12 sets. - **Fat-Free Mass Index (FFMI)** [11:13] — FFMI measures muscularity. Examples: Tom Holland ~20, Henry Cavill ~23, The Rock ~28-30. Natural limit for average responders is FFMI 22-23; low responders cap at 20-21; high responders can reach 24+. - **Controllable Factors Matter More** [14:43] — Researcher Zach Robinson shows that differences in muscle growth are often due to sleep, nutrition, and training effort, not genetics. Many 'low responders' improve dramatically with proper programming. ### Conclusion Genetics influence muscle growth speed and limits, but strategic training volume, specialization, and optimizing lifestyle factors can help anyone maximize their potential. Your genetics are a starting point, not a final destination. ## Transcript than 1,500 calories a day, yet his muscle growth speed is unheard of. At 15, before even touching a weight, his arms were bigger than most grown men. Meanwhile, this was me. Narrow shoulders, skinny frame, I look like a stick you'd find in your backyard. So, I dug into science to find a way to beat my crappy genetics. And I finally transformed from this to this. How? Well, there's three main ways that genetics affect your muscles. How fast they grow, which ones grow the fastest, and your natural limit. Let's start with speed, where I've got two perfect examples. My friend Max and Ryan, a record-breaking lifter. We even filmed a bench press video together not too long ago. After probably 7 or 8 months of lifting, I was able to get to 225 lbs on my bench press. So, the progression felt quite fast for me and it was definitely quite fast for me and it was definitely faster than my peers. For me, I don't know. I'm I'm kind of sad that people don't believe it's possible the conclusion that you can only achieve this by taking this. And that I wanted to be an example that this is possible. And then you've got the extreme outliers. Take Julian, a teenager who's built such a crazy physique in just a video questioning whether he was natural. >> The arms are literally as big as my leg. That's like I don't know. >> It's certainly possible that people respond better than others to certain a certain stimulus and that can be even due to the way they train. Maybe they've found a very effective method of training that he's managed to capitalize doubt, >> but obviously there is the possibility >> but obviously there is the possibility that he is lying. Um, and if he is, I think that's really unfortunate. Regardless of whether Julian is or isn't natural, the truth is very clear. Some people are genetically wired to grow muscle faster than the rest of us. Imagine you took 287 people and you had all of them do the exact same full body workout twice a week for 6 months. Back in 2016, a group of scientists did just that, but they used MRIs, DEXA scans, and ultrasound to measure muscle growth as accurately as possible. The results all over the place, but they quickly noticed three types of people. First, there were the hyper respponders. These people grew two to three times faster than the average, growing their muscles up to 30% bigger. Then, there was the average responder, where most people fell under, growing their muscles about 5 to 10% bigger. And finally, the low responders, who barely built any muscle, with some even losing muscle. And remember this was with the exact same gym bro never miss a training session together and after 6 months your body gets jacked whereas you've lost muscle. But what exactly in our genetics is causing this? Maybe it's possible to do something about it. Well, one genetic candidate is myostatin which stops your muscle from growing. But why? Isn't bigger muscle healthier? Well, in our ancestral days, we never knew when our next meal was going to come. And since carrying tons of muscle around burns a lot of calories, God looked out for us by hooking us up with myostatin, preventing you from getting too big. But what happens when you remove it? Well, that's born without myostatin, and they get abnormally massive as a result. And we see the same in dogs and even mice when you remove myostatin. But in humans, the first case of a human mutation in the mostatin gene was first documented in a 2004 study where a German newborn was pretty much jacked right out of the womb. By the time he was just 4 years old, he was able to hold 7 lb dumbbells straight out to his size. My friend Paul Durand, a natural bodybuilder, is thought to have this deficiency. This is what he looked like before even touching a single weight. So, I first noticed I was gifted at around age 5 to six cuz I was in the bush just playing around. I always like to flex my muscles just cuz like I could feel everything and then I was in the bush just kind of going like this. And similar to like this, just think of a 5-year-old with a bicep. I I was like, there's something to this. Starting in elementary school is when I would get accusations for being on steroids by like all my friends in about grade two, three, two to three. And then by grade like five, that's when it was like, "Okay, are you on steroids?" Like, "No, I'm not on steroids." So someone says even gotten my protein goals over the past like say 13 years of training. I can get away with not eating as much as I need or as other people would think you would need. I'm in a caloric deficit at all times. However, this mutation is actually extremely rare. In every one million people, maybe four might have it. So, it doesn't explain the differences we see in most lifters. Now, you might be wondering, is there a way to stop myostatin from working? It turns out there is. Scientists have very recently tested a myostatin inhibitor on monkeys. And the results, insane. Unfortunately, it's going to take years before this muscle drug is proven safe or even made available to humans. But there are three other ways you can work around your genetics. But first, how can bad in the first place? Well, some people think that if you're born with a wide frame that you have a body type that builds muscle faster. And there is some truth to this. A recent study investigated this exact question, and they found that wider framed people do tend to start off with more muscle. But when researchers looked at how quickly they built more muscle compared to actually pretty small, barely detectable. What a wide frame does do though is it creates the illusion of broader shoulders. And if you're like me and you were born with a narrow frame, don't worry. I'll show you later how I worked around that. But a better way to at how quickly you gain muscle and strength in your first year of training. After just one year of training, this is what Max looked like and this is what Ryan looked like. It would take most guys, including myself, at least a few years to achieve that look, let alone lift the amount of weight they were. So, here's a real question. If you're a low or average responder like me, are you stuck there forever? Not even close. You can absolutely speed up your progress and get way more out of your genetics than you think. The first strategy to do that is training volume. So, how many time I went to what I would truly describe as a high volume approach was describe as a high volume approach was the off season of after 2011 and I blew up. My upper body finally caught up to my legs. There was visible improvements. People were saying a lot of good things. That's Dr. Eric Helms, a pro-natural bodybuilder and one of the most respected researchers in the field. He told me that every time he's pushed his training volume higher, he's seen the fastest gains of his entire career, even after 20 years of lifting. But does more is better apply to everyone? Or are there people who actually do better with less? Well, Eric recently co-authored a one-of-a-kind study that may have finally answered this. So, one limb did a lower volume protocol, one limb did a wash out period where they returned to their normal training. They came back and they did it again. And this allowed us to see whether or not this was just kind of a statistical fluke. But everyone seemed to respond better to the higher volume protocol in the first arm and the f and the second arm of the crossover. And it doesn't indicate that there are certain people who are unique high responders to lower volume. So what does this mean for you? Well, if you're a lowresponder, you can potentially match the gains of a higher responder by simply doing more. But, and this is very important, how much more you do depends on where you're starting from. If you're currently doing under 12 sets per muscle per week, this is where you'll see the biggest benefit. Bump up your volume by about 20 to 30%. And that could mean adding a couple extra sets to the exercises you're doing or just adding more exercises for each muscle group. Now, if on the other hand, you're currently doing between 12 to 20 sets per muscle per week, now the returns are much smaller. And at this point, you only want to do more if you're confident your form, effort, and recovery are all already dialed in. Now, if you're already cranking out more than 20 sets per muscle per week, the extra push probably isn't worth a squeeze. Luckily, there is a trick that can make you look like you've gained 10 lbs of muscle, even if you've only gained two. Specialization. If you can only gain so much muscle each year and only recover from so much volume, the smartest move is to spend that volume budget where it'll make the most visual impact. For me, that was my shoulders. I was born with narrower clavicles. So, I basically had a 1:1 shoulder to waist ratio. And for context, the ideal ratio for aesthetics from a few studies is closer to 1.6, creating the Vtaper that most guys want and apparently most girls love. So, one year I decided to put everything else on maintenance and go all in on growing my shoulders. Visually, it was a complete transformation, as if my narrow shoulder can reap the benefits of Specialized Volume 2. Brett Contraras, who's dedicated his career to studying glutes, often has his clients train glutes three times per week, sometimes with up to 30 to 40 sets per week. And for personal interest, I actually trained my girlfriend, now wife, the same way. and she clearly outgrew the butt she thought she would genetically curse with. So, how do you actually apply specialized volume? Well, step one is to pick the to bring up. For guys, that usually means wider shoulders or bigger arms. Those are the muscles that make you look the most jacked. For women, glutes are obviously the most common focus, but honestly, it can be whatever one or two muscles you feel is your weak point. From there, start those focus muscles at around 10 sets per week, trained at least twice a week. Then you slowly want to add about two sets per week until you're up around 20 to 30 weekly sets. much volume you can personally recover from. But here's the important part. To save up recovery room for your focus muscles, you'll want to dial back everything else. So, keep your other muscles at about 8 to 12 sets per week. And for the areas that you're really naturally strong in, you can actually drop those even lower to just four to six hard sets per week, which is usually enough to maintain them. Run this for a few months, see how your body responds, and then decide if you want to repeat the cycle or shift your focus to a new muscle group. Now, this used to be very difficult for me to keep track of every Size Plus app, which automatically adjusts your routine to focus more volume where you need it the most, using the exact principles I just explained. train smarter, does that mean everyone can look like the rock? Not quite. The last piece of your genetic story is your natural limit. And the best way to measure it is with something called the fat-free mass index or FFMI. Think of it as your jack score. The higher it is, the more jacked you are. And for context, here's some examples. My creative director, Dennis, is around 18. Tom Holland and Spider-Man 20. Cristiano Ronaldo 21. I'm currently around 22. Henry Caval and Superman was at 23. Stallone and Rocky around 25. And the Rock or John Cena in their primes, you're looking at between 28 to 30. To calculate your score, first find the body fat photo that looks most like you. Take that number and multiply it by your weight in kilog. That's your fat mass. Now subtract that from your weight. That's your lean mass. Finally, divide that by your height in meters squared. I know this looks overwhelming. To make this easy, we've also built a calculator that does all the math for you, gives you a rank, and tells you how much more muscle you need to improve it. Just head muscle you need to improve it. Just head over to builtwithscience.com/fffi, bigger question is, how high can you actually push this number? To answer this, I turn to Dr. Eric Trexler. Using decades of data, he's modeled the most accurate road map we have for natural muscle growth potential. Let's start lifting usually has a fat-free mass index of 18 or 19. Here you can expect to gain about 8 to 10 lbs of muscle in your first year of lifting, about 5 lbs in year two, and then less and less each year onwards, eventually maxing you out at a fat-free mass index of about 22 to 23. Now, a low responder, you can gain about half as much, capping you at a fat-free mass index of 20 to 21, which is still lean and athletic and already more muscular than about 70% of the American population. But a high responder, completely different story. >> We know that some people get absolutely jacked when they lift, other people don't. Yeah, I've talked to people who train professional football players who they literally have to stop training upper body cuz their bicep gets so big they can't hold a football anymore. >> These guys can pack on over 20 lbs of muscle in their very first year and keep gaining steadily for years. In total, they might gain more than 40 lbs of muscle over a lifetime. That's enough to push their fabric mass index to 24 or higher, putting them in the top 1% of naturals, right around where my friends Max, Ryan, and Paul are. And then, of course, you've got steroid users. These guys are in a completely different league. Dr. Mike Isertel, who's open about being enhanced, he shared his DEXA scan with me, and I calculated his factory mass index score at a whopping 35, breaking the scale completely. Now, for my score at 22, that already makes me more muscular than about 95% of Americans. And at this stage, even putting on one or two pounds of muscle in an entire year is a win. So, if I set a goal of hitting 25, I would be dead before that happens. But to get to 23, I'd have to gain about 8 more pounds of muscle. It might take a while, but it's achievable target. But here's the encouraging part. Being lean actually makes you look way more jacked. Take Bruce Lee or Brad Pitt in Fight Club. Both of these guys don't have fat free mass indexes that are very high, just 20 to 21, but they look incredible because they're leaner. But here's the problem. Most people still never even get close to even that level. And it's usually not your genetics holding you back. Zach Robinson, a muscle growth researcher, recently showed that a lot of the differences that we see in muscle growth studies, they can't be explained by genetics alone. Instead, it's usually down to things that you can control. Sleep, nutrition, and training effort. Take Brian for example. He had been lowresponder. But once he joined our Build with Science program, we caught a ton of training and nutrition mistakes that he was making. Turns out he actually had incredible genetics, but it was a plan he was using that was holding them back. And thousands of our app members have experienced the exact same honestly never thought was possible. So before you just blame your genetics, I want you to commit to training and nutrition as if they don't suck. And if results, try our buildwithscience plus app for free for 2 weeks at buwithscience.com or by scanning this QR code. And if you want to see the two shoulder exercises that helped me finally broaden my neuroframe, check out this video right here. Remember, your genetics are just your starting point, genetics are just your starting point, not your final destination.