Ep. #364: The Definitive (and Practical) Guide to Muscle Hypertrophy

[00:00:27] Hey, Mike Matthews here from Muscle For Life and Legion Athletics. And in this episode of the podcast, we’re going to talk about muscle hypertrophy, which can be a rather confusing subject. I mean, it’s a confusing word. Many people don’t even know how to say it.

Hypertrophy is the right way to say it. And what does that word mean? Well, it is simply the technical term for muscle growth. And some people say that the best way to stimulate muscle hypertrophy is to use different rep ranges, to develop different kinds of muscle fibers.

Some people say that there are different types of muscle hypertrophy. They say that there is myofibrillar hypertrophy and sarcoplasmic hypertrophy. And if you aren’t emphasizing both in your training, they say, then you are leaving gains on the table.

And if you want bigger muscles in particular, the story goes, then you want to maximize sarcoplasmic hypertrophy and you do that by training with light weights and high reps, super sets, drop sets, and so forth. If you want stronger muscles, however, many people say that you want to maximize the myofibrillar hypertrophy. And you do that by training with heavy weights and low reps.

[00:01:45] And then there are other people still who say that muscle hypertrophy is almost entirely genetic. They say that your DNA determines whether you can build a lot of muscle or not and how quickly you’re going to build that muscle. And that how you train really isn’t going to make that much of a difference one way or another, so long as you follow a few loose principles.

[00:02:11] And then there is cardio, which most people say you should do as little of as possible or none of if you want to maximize muscle hypertrophy. 

[00:02:23] So if you have been trying to educate yourself on the topic and feel like you are just spinning in circles, I do understand I was in your shoes at one point as well. When I first started working out, I was just your average tall, skinny dude.

And for the first year, year and a half or so, I followed just cookie cutter run of the mill bodybuilding magazine workouts and it worked – kind of. By the end of my second year or so, I was a little bit less skinny. My chest in particular responded well to resistance training, so I had a little bit of a chest and a little bit of biceps, which also responded well, but otherwise hadn’t really progressed all that much.

And then fast forward about five and a half years, and I had gained a fair amount of muscle along the way, but it wasn’t exactly what you would have expected for seven, seven and a half years of dedicated weightlifting. In that period, I put on maybe 30 pounds of muscle.

I had gained maybe 30 pounds of muscle, no more than 35. Which is a lot for sure, but not for 7 to 8 years of training. You should be able to do that, most guys should be able to do that in their first three years. And for women, you could double that.

That’s a lot of muscle for women to gain. It’s a fair amount for men, a lot for women. And anyone who is familiar with my story knows that it’s around that time that I really started to educate myself on the science of gaining muscle and strength and made significant progress going forward.

[00:04:03] So in this podcast, I’m going to share with you the key lessons that I have learned along the way so you can avoid the mistakes that I was making in the past and get to your goals faster.

[00:06:10] All right, so let’s start with answering a simple question. The first question that we need to ask, which is what is muscle hypertrophy? Well, like I mentioned, it is simply the technical term for an increase in muscle size. Hyper means over or more. So muscle hypertrophy literally means the growth of muscle cells.

[00:06:32] Now, to understand what causes muscle hypertrophy and how it works, you first need to understand what muscles are comprised of. So muscle tissue is a complex structure with bundles of long strands of muscle cells that are sheathed in a thick band of connective tissue known as the paramecium.

There are three main components of muscle tissue and they are water, which makes up about 60 to 80 percent of muscle tissue by weight; glycogen, which is a form of stored carbohydrate that can make up anywhere from 0 to 5 percent of muscle tissue by weight; and protein, which makes up about 20 percent of muscle tissue by weight.

So to cause muscle hypertrophy, you need to increase the amount of water glycogen or protein in a muscle cell.

[00:07:28] Okay, so far so good. Simple enough, right? Now let’s talk about the two kinds of muscle hypertrophy. So when people say muscle hypertrophy, they’re generally referring to an increase in the amount of protein in the muscle.

And this is known as myofibrillar hypertrophy, which refers to an increase in the amount of protein contained in individual muscle cells. Now it’s called myofibrillar hypertrophy because myo means muscle and a fibril is a thread-like cellular structure.

[00:08:00] Myofibrillar hypertrophy is not the only type of muscle hypertrophy, though. There is also sarcoplasmic hypertrophy. Now sarco means flesh and plasmic refers to plasma, which is a gel-like material in a cell that contains various important particles for life.

We can just leave it at that, we don’t have to get too complicated with it. So sarcoplasmic hypertrophy then is an increase in the volume of the fluid and the non-contractile components of the muscle – the stuff that doesn’t contract like glycogen, water, minerals and so forth.

[00:08:37] And just to help you picture this in your mind, think of a muscle cell as this long cylindrical structure. We slice it open, so now we’re looking at a cross-section of it, and what you’ll see is that there are smaller cylindrical structures called myofibrils in this muscle cell.

And those are the contractile elements of the muscle cell. Those are the active elements that make the muscles move. Now they’re surrounded by this sarcoplasmic. And the sarcoplasmic, plus the actual myofibrils determine the size of the muscle cell in terms of diameter. Right? Because, again, this is a round cylindrical structure.

[00:09:22] So just for the sake of keeping this example simple, let’s say that this muscle cell has six myofibrils in it that are surrounded by sarcoplasmic. If myofibrils are added to the muscle cell, that is myofibrillar hypertrophy. So let’s say through training over time, that muscle cell now contains twelve myofibrils.

[00:09:42] Now what happens to the sarcoplasmic? Well it expands too? But it doesn’t necessarily expand in ratio to the myofibrils, meaning that while there will be more sarcoplasmic in an absolute sense, when myofibrillar hypertrophy occurs, there may not be more relatively speaking.

There may not be more when you look at the amount of space that the myofibrils take up compared to the amount of space that the sarcoplasmic takes up. So that’s myofibrillar hypertrophy, pretty simple, pretty well taped, scientifically speaking.

[00:10:17] Sarcoplasmic hypertrophy, though, is a bit more controversial because while we know that you can temporarily increase the sarcoplasmic volume of a muscle cell by doing things like getting a pump or loading creatine or eating a bunch of carbs, there is an ongoing debate as to whether these sarcoplasmic of a muscle cell can expand at a rate significantly faster than the myofibrils expand.

And if it can, can this expansion result in long term increases in muscle size? In other words, can you cause long term increases in muscle size by focusing on increasing the sarcoplasmic volume of your muscle cells as opposed to the myofibrillar elements? Some people say the answer is very obviously yes.

They’ll say if that weren’t the case, how do you explain a 170-pound powerlifter out squatting a 250 pound bodybuilder? Sarcoplasmic hypertrophy would seem to answer that question. The bodybuilder, in his quest to build the biggest muscles possible, has apparently developed muscles with more sarcoplasmic, but less contractile protein than the powerlifter. In other words, bigger but less functional muscles is kind of the idea.

[00:11:40] I think there’s a more likely explanation for this though. Strength athletes squat, deadlift, and bench press far more frequently than bodybuilders. And the more you do something, anything, the better you get at it. Therefore, powerlifters are probably just better at those key exercises than bodybuilders who perform them much less frequently.

And this is why you can find many examples of body builders that switch to powerlifting and gain strength very quickly as they improve their technique and just their level of comfort with the exercise and their willingness to push themselves in terms of set intensity – push themselves closer and closer to technical failure.

[00:12:26] That said, it does appear that sarcoplasmic hypertrophy is indeed more than merely a side effect of working out. And the reason for this revolves around something known as cellular swelling. So every time a muscle contracts, metabolic byproducts like lactic acid buildup in and around the muscle cells.

Your body then pumps more blood into your muscles to carry these compounds away, which is what makes your muscle cells swell. Now, these compounds also pull water into the muscle cells, making them swell even larger. And this reduces the amount of blood that can escape, which causes even more swelling.

Now we experience this cellular swelling, of course, as a pump, and there is strong evidence that this alone increases protein synthesis, which is the creation of new muscle proteins and the process that drives myofibrillar hypertrophy.

[00:13:30] So in other words, while sarcoplasmic hypertrophy in and of itself doesn’t contribute to overall muscle size as directly as myofibrillar hypertrophy, at least not over the long term, it does seem to stimulate more myofibrillar hypertrophy, thereby helping you get jacked faster.

And this is one of the reasons why it is a good idea for intermediate and advanced weightlifters in particular to include some higher rep work in their workout routines, which maximizes sarcoplasmic hypertrophy. In my opinion, beginners don’t need to worry about periodizing their training like this, that’s the technical term, for separating your training into phases where you increase or decrease volume or intensity.

So volume you can think of as the number of hard sets that you’re doing – simple way of looking at it. Intensity is the load that you are lifting in each set as a percentage of one-rep max. And the reason why I say this about beginners is if they just spend their first couple of years focusing on increasing their whole body strength with a lot of heavy compound weightlifting, working mostly in one rep range, let’s say 4 to 6, 5 to 8, 6 to 8, something like that.

And using a simple progression model like double progression, which is what my programs for men and women, Bigger, Leaner, Stronger and Thinner, Leaner, Stronger are based on, they are going to gain more or less all of the muscle that they possibly can in that period. Meaning they’re going to do just as well as if they followed the fanciest, most in depth, most intricate training program they could possibly find.

[00:16:51] Okay, so what about growing new muscle cells? So far, we’ve talked about expanding the size of existing muscle cells through the addition of myofibrils or sarcoplasmic, but what about creating new muscle cells all together?

[00:17:07] Now, this is another controversial question, because you may have heard of muscle hyperplasia. That’s an idea that’s been kicking around in the body building space for many years now. And it’s a technical term that means the formation of new muscle cells. Plasia means the development of cells. And the debate is whether it’s actually possible or not.

[00:17:28] So the people who believe that it is possible say that both muscle hypertrophy and hyperplasia contribute to overall muscle growth and muscle size, whereas the people who believe it is not possible say that it doesn’t occur at all in humans, at least under normal conditions. And any increase in muscle size is solely due to the two types of muscle hypertrophy that we just discussed.

[00:17:52] Who’s right? Well, if you flip open a physiology textbook, you will read that there is nothing we can do to increase or decrease the number of muscle cells in our bodies. In other words, all we can do is grow or shrink the size of the muscle cells that we have.

And by and large, most studies do show that that is indeed the case. That said, most of those studies were conducted with sedentary people. And there is some evidence that we may be able to add new muscle cells with enough years of hard training.

[00:18:32] Now, the first line of evidence for this comes from animal research, which found that hyperplasia can occur if you use a sufficiently brutal training protocol. For example, scientists from the University of Texas found that they could cause a 24 percent increase in muscle size due to hyperplasia when they attached a weight to a bird’s wing for 30 days. Now, although it’s not practical, other research has shown that you can cause hyperplasia in rats by cutting them open and partially destroying muscles. The things those crazy rats will do for gains.

[00:19:12] The second line of evidence is a bit more convincing. So there are a few studies that have shown that bodybuilders have more total muscle cells than their non lifting counterparts, which has led some to conclude that there many years of hard training must have caused at least some degree of muscle hyperplasia.

[00:19:31] There are a few problems with those studies, though. One: we have no idea how many muscle cells everyone had before they got into the bodybuilding. So it’s possible that the bodybuilders in those studies were just born with more muscle cells than sedentary people and therefore just had better genetics for bodybuilding.

Two: the studies didn’t directly measure or demonstrate muscle hyperplasia. Instead, they just found a correlation between bigger muscles and more muscle cells. Muscle hyperplasia may or may not have caused this to occur.

And three, most other studies have found that bodybuilders and sedentary people actually have more or less the same number of muscle cells, which would, of course, indicate that most bodybuilders have bigger muscles through growing the size of their muscle cells, not adding new ones.

[00:20:28] Another possible way to induce muscle hyperplasia in humans is steroids. For example, in a study conducted by a team of scientists at Mayo University, muscle samples were taken from two groups of powerlifters. Powerlifters who had used large amounts of anabolic steroids for several years and powerlifters who had never used steroids.

And after analyzing the muscle tissues, what the researchers found is that the steroid users had significantly more muscle cells than the natties. So it is very possible that getting on some #dedication is a good way to cause muscle hyperplasia.

And if that is true, it would help explain why people who have used steroids and especially those who have used steroids for a long time tend to keep at least some of their chemically enhanced gains years after they stop taking drugs. Okay, so it’s it for muscle hyperplasia.

[00:21:31] Let’s move on and talk about how to increase muscle hypertrophy – how to make your muscles bigger. Now, there are several factors that affect how much and how quickly you can stimulate muscle growth – muscle hypertrophy. This is one of the reasons why there is a lot of confusion out there as to the “best way” of going about it.

Some people say that you just need to stick to the basics, you just lift heavy weights and you progressively overload your muscles and you keep your volume moderate and so forth. Whereas other people believe that you need to make things much more complex, and especially as an intermediate or advanced weight lifter. 

[00:22:14] For example, you have probably heard that at least at some point in your training journey, you should start training different muscle groups differently according to their muscle fiber composition; that you should start including fancy programing techniques in your workout routine like rest-pause sets, supersets, and so forth; that you should start timing your meals specifically; and start swallowing handfuls of pills and powders every day.

[00:22:41] And then there are some people that say none of any of that matters as much as your DNA, as much as your genetics. And that most of your progress, or lack thereof, is going to come down to this hardwired programming that you were born with.

[00:22:56] So let’s unpack all this and let’s see what the current weight of the scientific evidence has to say. So first, let’s talk about muscle fiber type and how this affects muscle hypertrophy. So as you know, muscle fiber is a muscle cell. Those terms are interchangeable. And not all are the same.

Some muscle fibers are better suited for endurance activities and others are more suited for strength and power. So the former, the endurance fibers, you could say, are technically referred to as type 1 muscle fibers. And the latter, the strength and power ones, are type 2.

Now the type 1 fibers are also known as slow-twitch muscle fibers. You’ve probably heard of that. And these are dense with capillaries. They’re rich in mitochondria and myoglobin. And they are very efficient at absorbing oxygen from the blood, which makes them very resistant to fatigue.

This is why these type 1 muscle fibers can contract repeatedly for very long periods of time. They also, however, have about half of the potential for growth and power output as type 2 muscle fibers. Now type 2 muscle fibers are also known as fast-twitch muscle fibers.

And their structure and physiology make them better suited for generating strength and power. They also grow larger than type 1 fibers and they contract faster, but they also fatigue much faster, which makes them less suited to those longer endurance activities.

[00:24:31] Now, because of these differences, bodybuilders have claimed for many years now that you can and even should selectively target these muscle fiber types with different styles of training techniques. One of the more common ones that is talked about is using higher reps and lower weights to maximally stimulate the type 1 muscle fibers and then using higher weight and lower reps to maximally activate the type 2 fibers.

This way they say you can gain as much muscle as quickly as possible. And while the theory behind this approach may sound reasonable, when you start to look beneath the hood, things get messy.

[00:25:15] First of all, the idea that different kinds of strength training preferentially stimulates different kinds of muscle fibers simply isn’t true. Whether or not a muscle fiber type activates during your set depends more on how close you are to muscle failure than what rep range you use. In other words, as long as you finish your sets relatively close to failure, both heavy and light weights can stimulate both type 1 and type 2 muscle fibers equally well.

[00:25:47] Dr. Brad Schoenfeld made this clear in one of the most comprehensive reviews on muscle growth to date, which was published in 2010 in the Journal of Strength and Conditioning Research. And in it he says, “a fiber type prescription with respect to repetition range has not been borne out by research.”

Second, not all muscle fibers fit neatly into these type 1 and type 2 classifications. A large proportion of our muscle fibers share properties of both type 1 and type 2 cells and these “hybrid” muscle fibers can adapt well to both strength and endurance activities. And what this means is it is more or less impossible to only target your type 1 or type 2 muscle fibers with different kinds of training or rep ranges.

[00:26:38] The last problem with this idea of targeted muscle fiber type training is that most of the muscles in your body have a roughly even mix of type 1, type 2, and hybrid muscle fibers. Now, the calves are a notable exception because they tend to be about 60 to 90 percent type 1 muscle fiber.

And this is why there are people like me out there who have calves that refuse to grow no matter how much you train them. My calves are coming along millimeter by millimeter. This is why, though, the calves tend to be one of the most stubborn muscle groups that us weightlifters care about, because most muscles have around 50 percent, type 1 and type 2 muscle fibers and respond fairly well to resistance training.

The calves, however, in some people, I guarantee you, if I were to get a muscle biopsy of my calves, they would be 90 plus percent type 1 muscle fiber. They just refuse to grow because that type of muscle fiber has a very low potential for growth.

So anyways, what all of this means then is that even if you could target type 1 or type 2 muscle fibers with different rep ranges, you’d still want to use both high and low reps on all of your major muscle groups to emphasize both of the muscle fiber types.

[00:28:00] Now, you may have also heard that through certain types of training techniques, you can transform some of your low growth type 1 muscle fibers into higher growth type 2 fibers. And unfortunately, science shows that that is basically impossible.

With enough training, you may be able to slightly shift your hybrid muscle fibers about 10 percent or so toward the type 1 or type 2 ends of the spectrum based on how you are training. But that’s it. Your pure type 1 and type 2 fibers do not seem to change at all, regardless of how you train them or how long you train them for.

[00:28:37] And an instructive example of this comes from a study that was conducted by a team of researchers at the University of Memphis, which looked at the muscle fiber type of high level power lifters and people who had never lifted weights. And when I see a high level, I mean it.

The average bench press in the group that they were working with was almost 400 pounds and their average squat deadlift were both over 600 pounds. The result? Well, both the power lifters and the untrained people had the same proportion of type 1 and type 2 muscle fibers. In other words, it looked like their many years of very heavy and hard weightlifting had not resulted in more type 2 muscle fiber.

[00:29:21] The practical takeaway then is this: so long as you are using relatively heavy weights and you are training in the rep range of somewhere between 4 and 12 reps and you are regularly pushing yourself in your sets to about 1 to 2 reps shy of technical failure, you are going to experience plenty of type 1 and type 2 muscle fiber growth.

[00:29:45] All right, so now I want to talk about why that is. I want to talk about how strength training affects muscle hypertrophy.

[00:29:52] So the first thing that you need to understand here is that there are three primary triggers for muscle growth. There are mechanical tension, muscle damage, and cellular fatigue.

[00:30:04] Mechanical tension refers to the amount of force produced in muscle fibers. When you lift weights, you produce two types of mechanical tension in your muscles. You produce passive and active tension. Passive tension occurs when your muscles are stretching. And active tension occurs when they are contracting.

[00:30:23] Now, muscle damage refers to microscopic damage caused to the muscle fibers by high levels of tension. This damage then requires repair, and if the body is provided with proper nutrition and rest, it will make the muscle fibers larger and stronger to better deal with future bouts of tension.

[00:30:45] Now, it’s not entirely clear whether muscle damage directly stimulates muscle growth or whether it’s just a side effect of mechanical tension which is stimulating the muscle growth. But as of now, I do think that muscle damage deserves its place on the list here.

[00:31:02] The third pathway, muscle-building pathway, is cellular fatigue, which refers to a host of chemical changes that occur inside and outside the muscle fibers when they contract repeatedly. Now, research shows that out of these three pathways, mechanical tension is the most important one for muscle growth. In other words, mechanical tension produces a stronger muscle-building stimulus than muscle damage and cellular fatigue.

[00:31:31] These three pathways to muscle growth also relate to what scientists call this strength-endurance continuum, which works like this: heavy lower rep weightlifting primarily increases muscle strength and results in higher amounts of mechanical tension and muscle damage, but less cellular fatigue; while lighter, higher rep weightlifting primarily increases muscle endurance and results in lower amounts of mechanical tension and muscle damage, but more cellular fatigue.

[00:32:04] Now, given that basic theory that you just learned, which style of training between those two do you think would generally result in more muscle gain over time? That’s right. The heavy lower rep work because it will produce higher amounts of mechanical tension and muscle damage over time than the lower rep lighter work.

[00:32:26] Now, this has actually been demonstrated in a number of studies, for example, in a study that was conducted by scientists at the University of Central Florida. 33 physically active resistance-trained men were separated into two groups.

Group one was a high volume, the moderate-intensity group that did four workouts per week, consisting of four sets per exercise in the 10 to 12 rep range, or about 70 percent of one rep max. And group 2 is a moderate volume, high intensity group that did four workouts per week, consisting of four sets per exercise in the three to five rep range or about 90 percent of one rep max.

Both groups did the same exercises, which included the bench press, back squat, deadlift, and seated shoulder press. And both were instructed to maintain their normal eating habits and to keep food diaries. And after eight weeks of training, what the scientists found is that the high intensity group gained significantly more muscle and strength than the high volume group.

The researchers cited two main reasons for why the heavier training beat out the lighter and not only strength gain, which is not surprising, but mostly gain as well. One was higher amounts of mechanical stress imposed on the muscles.

The high volume training, on the other hand, caused higher amounts of metabolic stress, the cellular fatigue that we just talked about. And the second reason cited was greater activation of muscle fibers. And this in turn, results in greater muscle hypertrophy across a larger percentage of the muscle tissue.

[00:33:55] And this fundamentally is why I am always saying that as a natural weight lifter, your primary goal is to get stronger, to increase your whole body strength, and especially on key compound exercises like the squat deadlift and bench and overhead press. The key exercises that involve the most muscle mass.

[00:34:16] In other words, it really is this simple: the more weight you can push, pull, and squat for a reasonable number of reps, let’s say anywhere between 4 and 12. The more muscular you are generally going to be. And that is why my Bigger, Leaner, Stronger and Thinner, Leaner, Stronger programs focus on heavy compound weightlifting. And that’s also one of the reasons why those programs are so effective. 

[00:34:39] All right, now let’s look at diet. How does your diet affect your ability to gain muscle?

[00:34:45] Now, you probably know that you need to eat enough protein to build muscle effectively. Most people know that specifically anywhere from 0.8 to 1 gram of protein per pound of body weight per day is going to work well for most people under most circumstances.

What you may not know is that you also need to eat enough calories. This is very important. Now, technically speaking, a calorie is the amount of energy that’s required to heat one kilogram of water, one degree celsius at one atmosphere of pressure. That’s the technical definition.

And the relationship between the amount of calories that you eat and the amount of calories that you burn is known as energy balance. And energy balance greatly impacts both your body weight and your body composition.

For example, if you feed your body less energy than it burns, you’ve created an energy or a calorie deficit that will result in weight loss. If it is sustained for a period of time. Now, this calorie deficit, this energy deficit will also impair your body’s ability to create muscle proteins, which can slow down or even halt muscle growth altogether.

[00:35:56] Now, the reason for this, the physiology in play is fairly complex. But the long story short is that when you restrict your body’s energy intake, it shifts into an energy conservation or energy triage mode wherein certain bodily functions are given priority over others.

And although we may feel differently about it, building bigger muscles is not vital for survival. And it also requires quite a bit of energy. So muscle hypertrophy is rather low on the list of priorities when energy intake is restricted.

A calorie deficit can also reduce anabolic and increased catabolic hormone levels, which causes a systemic shift away from muscle gain and toward muscle degradation. And last but not least, cutting your calories almost always entails reducing your carb intake, which is going to result in a decline in performance in the gym. And the less you can lift in the gym and the less muscle endurance you have in the gym, the worse your progress is going to be.

[00:37:06] Now, all of that is why it is commonly believed that you simply cannot build muscle and lose fat at the same time – and that is not entirely accurate. If you are new to resistance training or to proper strength training or you are coming back to the gym after a layoff, you can achieve the holy grail of fitness.

You can achieve a body recomposition. What is true, though, is you will never gain as much muscle in a calorie deficit as you would when you are in a calorie surplus. And also, if you are in intermediate or an advanced weightlifter, if your newbie gains are behind you or your muscle memory gains are behind you. If you were just in the groove in the routine, you probably are not going to be able to gain any muscle to speak of when you are dieting.

[00:37:55] So when you want to gain muscle as quickly as possible, what do you want to ensure regarding your calorie intake? That’s right. You want to ensure that you are not in a calorie deficit or that you are in a calorie deficit as infrequently as possible.

And that remains true regardless of your dietary protocol, regardless of how you are timing your meals or how you are portioning your macros. So if you are low carb, if you are doing IF or carb cycling, or maybe you’re just a standard flexible dieter or a vegan or whatever.

If you are in a calorie deficit, more often than not, you are going to struggle to gain muscle and strength, period. On the other hand, if you ensure that you are in a slight calorie surplus, more often than not, you are going to have a much easier time of it.

[00:38:47] All right, let’s move on to genetics now. How do genetics affect muscle hypertrophy? Now, for many people, genetics is a rather unpalatable word, is often associated with things that you’ll want to change, but you can’t. And the bad news actually is that muscle hypertrophy is one of those things.

We all do have hard limits as to how much muscle we can gain. However, unless you want to be a top tier bodybuilder or a fitness competitor, you can gain more than enough muscle to look and perform the way that you want. Just how much, though, you might be wondering? I get asked this all the time.

I wrote an article on it and recorded a podcast on it. Both are titled something like “How Much Muscle Can You Gain Naturally”. So if you really want to dive into that subject, check out the article or podcast. But I will just summarize here. There are many physiological variables in play, but you can get a fairly accurate estimate of your natural muscle building potential by analyzing your bone structure.

You see, research shows that people with larger bones tend to be more muscular than people with smaller bones. They also tend to have higher testosterone levels and gain muscle faster when they start lifting weights. So what this means then is big-boned people do appear to have more genetic potential for strength and size than smaller boned people.

[00:40:10] Now, what qualifies as big-boned, though? And how do you measure up? Well, the two best indicators of your overall bone structure are the circumferences of your wrists and ankles. Height being equal, people who have wider wrists and ankles tend to be naturally more muscular and have a higher potential for muscle growth than those with narrower ones.

[00:40:36] Now, if you are like me and you don’t even need to measure anything to know that you have slender bones, take heart because everyone can gain a significant amount of muscle if they eat and train correctly and remain patient. And you probably don’t have to gain as much muscle as you might think to have the body you really want, to have a body you can be proud of.

Specifically, most guys only need to gain about 15 to 20 pounds of muscle to build an impressive physique by normal standards, maybe not by Instagram or YouTube standards, where anything less than certified meat ball is frail and anything above 10 percent body fat in guys is obese, but by every day mentally balanced look could feel good standards, adding 15 to 20 pounds to an average guy’s physique is going to make a big difference.

And if you really want to go to the next level as a guy, we can say it’s probably closer to 35 pounds or so. That’s where you really start to look like a fitness model. And in women, I would say it’s probably 10 to 15 pounds by normal standards of muscle added in the right places gives most women the type of physique that they want.

When you combine that with the right body fat percentage, which is generally around 20 percent. And for women who want to be particularly muscular, it’s probably upwards of 25 pounds or so.

[00:42:02] Okey dokey, let’s talk cardio. How does cardio affect muscle hypertrophy? Now, if you spend enough time in the fitness racket, you are going to hear this. If you want to be small, weak and pathetic, then you need to do more cardio. And there’s some truth here. Cardio does indeed interfere with muscle hypertrophy, but it’s not that cut and dried.

[00:42:28] You see, cardio hinders muscle growth in two ways. In the short term, it can interfere with strength and muscle gain by increasing general fatigue levels, which makes it harder to progress in your weightlifting. And in the long term, cardio can interfere with strength and muscle gain by disrupting cell signaling related to muscle hypertrophy.

[00:42:50] Good evidence of the first point can be found in a study that was conducted by scientists at the University of Sao Paulo. To see how doing cardio before heavy strength training affected muscle growth. the researchers split 10 men into three groups.

The first group did four sets of half squats for as many reps as possible, with about 80 percent of their one rep max. The second group did 30 minutes of HIIT cycling. One minute of easy pedaling, followed by one minute of all out effort, followed by the same leg workout.

And the third group did 30 minutes of HIIT running. The same protocol is cycling, followed by the same lower body workout. Now, after each workout, the researchers tallied up the total weight lifting volume of each group and found that the first group, the no cardio group, performed significantly better than the other two groups.

This study didn’t measure muscle growth, but due to much of what we have discussed in this podcast, it is reasonable to assume that the first group would also gain significantly more muscle and strength over time if the experiment were played out over a longer period.

[00:44:02] Now, as to the second point of how cardio can interfere with strength and muscle gain, the disruption of cell signaling – working out produces a cascade of cellular, genetic and hormonal changes to repair the damaged muscle fibers and to make your muscles bigger, stronger, and better able to deal with future bouts of training –  future bouts of tension. 

[00:44:26] Cardio, however, triggers a very different set of cellular adaptations that cause muscle cells to become smaller and more resistant to fatigue instead of larger and stronger. The exact mechanisms that cause this are beyond the scope of this podcast.

But the summary is this: doing too much cardio suppresses the normal levels of anabolic signals triggered by resistance training, which reduces muscle and strength gain over time. In other words, the more cardio you do, the harder it becomes to get bigger and stronger.

Furthermore, the longer your cardio sessions are, the more pronounced this interference effect, as it’s known in the literature, is in each cardio session.

[00:45:16] It would be wrong to say that cardio has no place in your workout routine, though. First of all, cardio provides some health benefits that you probably can’t get with strength training alone. And these are primarily cardiovascular benefits, unsurprisingly.

Second, there is some evidence that doing regular cardiovascular exercise can help you recover faster between the individual sets of your weight lifting workouts, which you could turn into more work done per workout, which would produce a larger muscle-building stimulus.

And third, research shows that doing cardio while lean bulking can make it easier to lose fat during your post bulk cut. More good news is that studies show that you can minimize or even eliminate the negative effects of cardio on muscle hypertrophy by keeping your cardio workouts relatively short 30 to 60 minutes at most.

And the shorter better, by doing cardio relatively infrequently, three or four times per week at most, by using low impact forms of cardio like cycling, swimming, and rowing, instead of a higher impact form of cardio like running, which requires more recovery by doing your cardio after your strength workouts, not before.

And by doing your strength and cardio workouts on separate days, or at least by separating them by at least a few hours. If you stick to that simple plan, you should have no trouble building plenty of muscle and gaining plenty of strength while also including cardio and your workout routine.

[00:46:54] All right, so now let’s get to a practical summary of everything that we have discussed. Let’s talk the best way to stimulate muscle hypertrophy. So as you have gathered, muscle hypertrophy is a pretty complex subject and scientists are still investigating it.

And there are still many more questions than answers and still many nooks and crannies that need to be peered into. And that’s probably to be the case for a long time. But we do know enough to say this, if you do the following five things, you can gain all the muscle and strength that you want, assuming you don’t have body dysmorphia.

So the first is: do lots of heavy compound strength training. The second is: do a relatively small amount of cardio. The third is: maintain a slight calorie surplus of 5 to 10 percent. The fourth is: follow a high protein, high carb diet. And the fifth is: take supplements that are proven to accelerate muscle gain.

[00:47:51] Let’s review each of these steps in turn. So step one, do lots of heavy compound strength training. Now, there are many ways to train your muscles and many right ways to train your muscles. But when the goal is gaining strength and gaining size as quickly as possible.

Nothing beats heavy compound weight lifting. This is better than workout machines, pump training or classes, bodyweight exercises, yoga, pilates, and everything else you can do to develop more muscle definition. Now, what do I mean by this?

Well, by heavy I mean, you should be working primarily with weights in the range of 75 to 85 percent of your one-rep max, which generally means working in the repp range of 4 to 12 reps. And I recommend that you work in the lower end of that rep range on your big compound lifts, which are the lifts that involve several major muscle groups and more than one joint like these squat, deadlift, and bench press.

On those exercises, I particularly recommend the rep range of 4 to 6 or 5 to 7, maybe even 6 to 8 reps, which is gonna be somewhere around 80 to 85 percent of your one-rep max. And then on isolation exercises, which involve just one joint in one major muscle group, you can work with higher reps, less weight, somewhere closer to 75 percent of one-rep max.

[00:49:19] Now, as far as routines go, there are many out there that you can follow that meet those criteria. But I recommend that you start with a proven classic like the push-pull legs routine, which you can learn about or at muscleforlife.com If you search for “push-pull legs” or you can follow one of the programs in my books for men and women Bigger Leaner Stronger and Thinner Leaner Stronger which are built around a push-pull legs routine.

[00:49:45] Okay, step two do a relatively small amount of cardio. Now as we are talking maximum muscle growth, we are talking about lean bulking of course, which is what we’re gonna talk about in the next step – the calorie surplus.

But when you are doing this, when you are lean bulking, you don’t have to do any cardio, but if you include small amounts, it can benefit your recovery and your health and your body composition. So personally, what I like to do when I’m lean bulking is: I will walk my dog four or five times per week for about 15 minutes.

Little dog, chihuahua. I’ll also do two 25, maybe 30 minutes cycling sessions on an upright bike that I have in my basement. And I will occasionally participate in hobbies that keep me active, like golfing or hiking or exploring museums.

I live in the Washington, D.C. area. Now, if you aren’t sure as to what kind or how much cardio you want to do or you should do. I would say just start with a couple hours of walking per week. Easy place to start. That’s really all it takes to get some of the benefits of cardio without interfering with muscle growth at all.

[00:50:53] The next step, step three: maintain a slight calorie surplus of about 10 percent. I know I just said about 5 to 10 percent, but I’m gonna go with 10 percent because 5 percent has such a small margin for error that you might just accidentally put yourself in a deficit.

So let’s just say maintain a calorie surplus of about 10 percent. This is enough to maximize muscle growth without having to deal with unnecessary fat gain, which is what will happen if you start going into larger surpluses. If you were in a 20 percent calorie surplus, you’re probably not going to gain muscle any faster than a 10 percent unless all the extra calories are coming from carbs and you’re able to turn the extra carbs into extra intense training.

But even that probably won’t make that much of a difference. What you will notice, though, is you are going to gain fat a lot faster, which means you will have to end your lean bulk sooner, which in the end will probably negate any benefits that you might see in terms of performance.

So what we’re looking for here is gaining anywhere from a half a pound to a pound per week if you’re a man and about half of that if you are a woman. If you can do that and see your numbers going up in the gym, at least on your key lifts, you are doing it right.

Now, if you are new to weight lifting, you can easily double those numbers for your first 3 to 6 months or so – the newbie gains phase. But they should then settle into that range.

[00:52:17] Step four, follow a high protein and high carb diet. Now, as you learned, aside from water, the main component of muscle tissue is protein. Therefore, for muscle hypertrophy to occur, you need to provide enough of the raw material, the protein, which breaks down to amino acids, for your muscles to grow larger and stronger.

Now, how much? Well, one gram per pound of body weight per day is what most research shows is optimal for people in most circumstances. You can go a bit lower if you want or even a bit higher if you want. But somewhere around 1 gram per pound per day is going to be good.

You don’t have to eat absurd amounts of protein while lean bulking regardless of what you might hear in the gym, locker room or read in the bodybuilding magazines. I know because I’ve been there at one point in my life I was eating upward of 400 grams of protein per day. It was disgusting.

[00:53:09] Now after your protein intake, your next priority, when you are trying to build muscle as quickly as possible, at least as far as your diet goes, is your carbohydrate intake. Now you can check out an article on Muscle For Life on muscle glycogen to learn why if you search for “muscle glycogen”, but the bottom line is you are going to have a much easier time gaining muscle and strength on a high carb diet than a moderate or a low carb one.

And that’s why I recommend that you start around 2 grams of carbs per pound of body weight per day when you are lean bulking and you work up from there. If you need to increase your calories to continue gaining weight and size, which you probably will at some point.

[00:53:53] Okay, the fifth and final point, which is taking supplements that are proven to accelerate mostly. Now I save this for last because it is far less important than proper diet and training. Supplements do not build great physiques only dedication to proper training and nutrition does.

That said, there are some safe natural substances that are out there that have been scientifically proven to deliver benefits such as increased strength, increased muscle endurance, and increased muscle growth and even fat loss. 

[00:54:27] For example. creatine is one that I recommend. It is probably the most researched molecule in all of sports nutrition and the evidence is clear in most people. It will help them build muscle and gain strength faster. It will improve anaerobic endurance and it will reduce muscle damage and muscle soreness resulting from workouts, which means faster recovery.

And all you got to do is take five grams per day. And it is not bad for your kidneys, you may have heard that, but that has been proven false in scientific research. If you have kidney disease or kidney damage or you are missing a kidney, you probably shouldn’t take creatine.

You should probably talk to your doctor first. But if you were a normal, healthy person with normal, healthy kidneys, you will be totally fine. All you gotta do is make sure you stay hydrated, which you should be doing anyway.

[00:55:15] Now, as far as products go, you can buy creatine monohydrate, which is the form that I recommend, in bulk, or you can get a fancy pants post-workout supplement like mine, which is called Recharge, made by my supplement company Legion, which is what I use myself.

It has a clinically effective dosage of creatine along with two other gradients that can help you recover faster and better from your workouts.

[00:55:41] Another supplement that you should consider taking is protein powder, not because it has any special muscle-building properties, but simply because it is very convenient and it helps you hit your daily protein target easily.

Getting all the protein that you need from whole foods can be impractical and drinking a protein shake is very easy. And this is really the main reason I created and I use a whey protein supplement which is called Whey+. It is a 100 percent whey isolate protein, naturally sweetened, naturally flavored.

And there is some evidence that whey in particular is great for post-workout use, but that’s a minor point. If you eat a chicken breast or some Greek yogurt or skyr or cottage cheese or whatever after working out, that is going to be more or less as effective as drinking a whey protein shake.

Now, these days, I should also mention that I like to mix my way, which I take after my workouts, simply because I get to the office, it’s easy, I don’t feel like cooking a meal, cooking at breakfast at the office, I’d rather just drink down some protein.

So I like to take one scoop of my whey isolate and mix it with one scoop of my micellar casein, which is called Casein. And I mostly like it just because I think that the tastes work well together and the mouthfeel works well together. There’s nothing particularly special about mixing them, but that’s what I’m doing these days.

[00:57:04] Okay, so two other supplements that you should consider, which I’ll just talk about quickly, I don’t want to turn this into a big supplement pitch, are beta-alanine and citrulline malate simply because they can improve your performance in the gym.

They can increase the amount of work you can do in the gym, which of course translates into more muscle gain over time. And in the case of beta-alanine, there is some evidence that it can also directly increase muscle gain similar to but not as effectively as creatine.

And as far as getting those supplements again, you can buy them in bulk or you can find them in my pre-workout supplement Pulse, which contains clinically effective dosages of both, along with several other ingredients that increase muscle endurance, increase strength, improve mood, and more.

[00:57:52] Okay, so let’s wrap up this rather long podcast with a bottom line. What are the key takeaways? Well, you can spend hundreds of hours studying muscle hypertrophy and barely scratch the surface. It is an extremely complex process that involves scores of physiological functions and adaptations.

Fortunately, you do not need to be a scientist to have a working understanding of the research and to know how to use it to build muscle quickly and efficiently.

[00:58:21] The key takeaways are: 

[00:58:22] 1. So long as you train with heavy loads and a moderate volume, and so long as you come close to failure in most of your heavy sets, you are going to stimulate both myofibrillar and sarcoplasmic hypertrophy. 

[00:58:38] 2. You may or may not be able to grow new muscle fibers, muscle hyperplasia, after many years of strength training. Regardless, almost all of your gains are definitely going to come from increasing the size of your existing muscle fibers, not adding new ones.

[00:58:57] 3. You do not need to use different training methods to target different muscle fiber types. 

[00:59:02] 4: Heavy compound strength, training is the best way to stimulate muscle hypertrophy.

[00:59:08] 5: You need to regularly eat more calories than you burn over time to maximize muscle growth. Six: How much muscle you can build naturally is limited by your genetics, but chances are you can gain more than enough to look the way you want to look.

[00:59:25] And finally, let’s reiterate the five-step process you need to follow to put all of that into practice and build as much muscle as possible.

[00:59:33] 1. You need to do a lot of heavy compound strength training. 

[00:59:36] 2. You need to do a relatively small amount of cardio. 

[00:59:39] 3. You need to maintain a slight calorie surplus of about 10 percent. 

[00:59:44] 4. You need to follow a high protein and high carb diet.

[00:59:44] 5. You don’t need to, but you can and you should if your budget allows, take supplements that are proven to accelerate muscle gain.

[00:59:56] If you do those things, you will have no trouble building muscle like clockwork.