Written by Garett Reid | NSCA, CSCS, CISSN, M.S.E.S.S
Fact checked by Kirsten Yovino, CPT Brookbush Institute
FACT CHECKED
Muscular hypertrophy is the essence of bodybuilding, strength sports, fitness…you get the idea. Muscle hypertrophy is what we think about when we think of going to the gym. With this in mind, it’s a pretty important physiological process to understand if you have any interest in building muscle and improving your physique. At the same time, there’s a lot to know, and it can be hard to distinguish what’s important to know and what’s not. That said, this article is going to be what you need to know about muscle hypertrophy, and in a way, you can understand. In this article, you’ll learn:
- What is muscle hypertrophy?
- How does muscle hypertrophy occur?
- Most important training variables for muscle growth
- Nutrition for muscular hypertrophy
- Best supplements for muscle gain
What Is Muscle Hypertrophy?
Muscle hypertrophy is the technical term for muscle growth or “getting jacked.” The term “hypertrophy” means “the enlargement of muscle tissue” so it can actually be paired with other organs; perhaps “hypertrophy of the heart” is the most commonly heard use, which means the enlargement of the heart (cardiac muscle tissue). Within our context, we mean skeletal muscle hypertrophy, which simply means the enlargement of muscle.
Skeletal muscle hypertrophy comes from placing a stimulus on the muscle by lifting weights and eating the correct nutrition to support growth. It is the heart of bodybuilding and an integral aspect of any form of fitness.
Two Types Of Skeletal Muscle Hypertrophy
As the exact mechanisms are still not entirely understood, it’s generally agreed upon that there are two different forms of muscle hypertrophy; sarcoplasmic hypertrophy and myofibrillar hypertrophy.
Even though these two types of hypertrophy occur through different mechanisms, they rarely occur completely distinct from the other. They can occur to the same degree, or one can occur to a greater degree than the other. As of now, researchers still aren’t entirely positive on what factors influence each type and to what degree, but here is a breakdown.
1) Sarcoplasmic Hypertrophy:
Sarcoplasmic hypertrophy is the enlargement of a muscle due to an influx of intracellular, non-contractile fluids. What this means is that muscle gets engorged, but there is no real increase in muscular strength. Sarcoplasmic hypertrophy is generally seen to a greater degree in bodybuilders when compared to strength athletes.
2) Myofibrillar Hypertrophy:
Myofibrillar hypertrophy is when actual actin and myosin contractile units are added to a muscle. As actin and myosin are the actual contractile mechanisms on a muscle (they pull on each other to contract a muscle), this means that it can aid in increasing strength. This type of hypertrophy is generally seen to a greater degree in strength athletes such as powerlifters when compared to bodybuilders.
Hyperplasia vs Hypertrophy
Hyperplasia is another type of tissue enlargement but occurs due to the addition of actual fibers. With the above types of hypertrophy, the muscle maintains the same amount of muscle fibers which are then filled with fluids or contractile units added to the existing fiber. Essentially, with hypertrophy, the muscle cells get bigger (big muscle fibers), but the number of muscle fibers doesn't increase. Hyperplasia occurs by a new fiber actually forming.
Think about a piece of braided yarn representing a muscle fiber. Hypertrophy would exist by extra pieces being added into that single braid. Hyperplasia would be when a distinct, separate piece of yarn is formed and then added next to the other piece of yarn.
That being said, researchers still aren’t sure if hyperplasia actually occurs to muscles on a regular basis. Even if it did, we have no idea how to initiate the process. Therefore, this is mainly important to understand what muscle hypertrophy is by knowing what it’s not.
Training Variables For Optimal Muscle Hypertrophy
When it comes to making your muscles grow and how long it takes for muscles to grow, it’s not going to happen by itself. Even if you do go to the gym, if you are training incorrectly, your muscle growth will not be what it could be. Therefore, we are now going to go over what your training should look like if you want to optimize your muscle growth.
Build Volume: The Most Important Variable
There have been numerous mechanisms proposed to be the driver of muscle hypertrophy. Examples that have been given include:
- Mechanical Tension
- Muscle Damage
- Metabolic Stress
- Volume
Out of all of these, the one mechanism with the most research to support its role in muscle growth is volume accumulation1. Volume is basically the total amount of weight that is placed on a muscle which can be expressed with the following equation.
Volume = Load X Sets X Reps
What this means is that you gradually want your total volume to increase as time goes on. However, this will not be linear as you will need to adjust the load to increase the weight. The best way to think about this is similar to a stock graph. While there are ups and downs, there is a general trend of growth. Without this, you will not grow.
What Loads To Use For Muscle Growth?
Previously, researchers had developed a rep continuum, which explained how to train for different variables such as strength, hypertrophy, power, and endurance. For hypertrophy training, it was believed that you had to use moderate weight with moderate reps in order to grow your muscle. This looked something like using loads of 70-85%1RM within the 8-12 rep range.
While this isn’t exactly wrong, the mechanism is not as exact. As it turns out, you can induce muscle hypertrophy with just about any load as the true mechanism for muscle growth is volume.
What this means is that the reason using moderate weight and reps has been so effective is that it allows the greatest build-up of volume with sufficiently heavy weight. This is because you are able to exponentially increase your volume with a minimal drop in weight. To explain, when we look at the number of reps you can perform with a given weight, we will compare 90%1RM-75%1RM.
- 90%1RM - The maximum amount of times you could lift 90%1RM is 4
- 75%1RM - The average amount of times you could lift 75%1RM is 10
Now let’s say 100 lbs is your 1RM:
- 90%1RM = 90lbs. X 4 = 360lbs. Total
- 75%1RM = 75lbs. X 10 = 750lbs. Total
As you can see, by using just 17% less weight, you are able to lift more than twice the volume.
What Reps And Sets To Use For Muscle Growth?
As you want to use a load from 70%-85%1RM and bring your set close to failure, you will primarily stay in a rep range of 8-12 reps. When it comes to sets, 3 seems to be optimal for the majority of exercises.
If you wanted to get in more variety, you could just perform an exercise with 2 sets or even 1. Generally, when this is done, the sets are performed with very high reps, 12-15, but there is no concrete rule.
Use 4-6 Exercises Per Muscle Group Weekly
When looking at optimal volume, a broad range of 10-20 sets per week is generally given. However, most trainees would do well sticking around the middle with 15 sets. Assuming you’re using 3 sets per exercise, you’re left with 4-6 exercises per muscle group. As mentioned above, you could include more exercises by using a smaller amount of sets for some smaller exercises. Take the chest for example. In the following scenarios, Example 1 has less exercises than example 2 but more sets.
Example 1 (5 Exercises W/ 16 Sets):
- Bench Press x 4 sets
- Incline Dumbbell Bench Press x 3 sets
- Dips x 3 sets
- Cable Fly x 3 sets
- Dumbbell Pullover x 3 sets
Example 2 (6 Exercises W/ 15 Sets):
- Bench Press x 3 Sets
- Incline Dumbbell Bench Press x 3 Sets
- Dips x 3 Sets
- Incline Cable Fly x 2 Sets
- Decline Cable Fly x 2 Sets
- Dumbbell Pullover x 2 Sets
For more information, check out our article: How Many Exercises & Sets Should I Do Per Muscle Group & Workout?
Implement Variety On A Regular Basis
We want to be clear that adding variety is not the same as “muscle confusion.” By adding variety, we mean that we alter the exercises slightly on a consistent basis. This can mean changing the grip, using a different load, or using a different implement (i.e., dumbbell hammer curls and rope hammer curls).
Just about every muscle we have is composed of several smaller heads with different lengths that are situated at different angles. This is why we are basically able to manipulate our body in just about any fashion assuming we have the mobility.
Further, different muscle heads are composed of a different combination of muscle fibers. Some muscles tend to have more Type I muscle fibers, while others have more Type II muscle fibers. Still, these ratios of muscle fibers can also differentiate between people.
What all of this means is that if you only stick with one set of exercises, you won’t train every muscle in your body optimally. In fact, this has been proven through recent studies.
Researchers have discovered a phenomenon known as “regional hypertrophy,” which simply means that growth in a muscle is not uniform2. That is to say, some parts of a muscle grow more than other parts. It seems the mitigating factor is exercise selection. Some exercises will put more stress on the distal region (part farther from the joint) while others generate more growth centrally.
Therefore, you want to alternate various movements to ensure you’re training the entire muscle. For example, for the cable chest fly, instead of only using chest-level height, drop the pulley to pull upward as well as raise the pulley to pull downward. Further, include various grips, hand/foot placement, and even implements (dumbbell vs. barbell).
This should be done in a planned and orderly fashion, though. You don’t just show up at the gym and do whatever to “confuse” the muscles. It means you follow your plan while making alterations:
- For your larger compound movements, alternate exercises every 6-8 weeks.
- For your smaller accessory compound movements, alternate exercises around every 3-4 weeks.
- If you are just using a different hand grip or angle on smaller isolation exercises, you could alternate every 1 or 2 weeks.
The Most Important Principle For Muscle Hypertrophy
When looking at the big picture, your primary goal is to gradually place a greater load on your muscles over time. This is known as the principle of progressive overload and is the root of your training, whether you’re going to the gym for muscle growth or strength.
Our bodies are incredibly complex and have a set of physiological systems which will help us adapt to the surroundings we are in. A great non-muscle example would be a person’s cardio-respiratory system adapting to living at high altitudes with lower levels of oxygen.
You need to understand that our body doesn’t necessarily want muscle. This is why you have to go to the gym in the first place! It’s also the reason you’re reading this article as building muscle is not as easy as just going to the gym. Further, we’re sure you know of someone who has been bedridden for an extended period or has had to have a cast. After they are able to get out of bed or take off the cast, their muscles have atrophied because their body wasn’t using them.
Therefore, a better way to look at muscle growth is that you have to give it a reason to NEED muscle. Your body will grow and adapt if there’s a reason.
Similar to living in high elevations, we have systems that will cause our muscles to become larger and stronger when we find ourselves in a situation in which it is necessary. For example, I’m sure you have heard of some athletes, perhaps rock climbers or swimmers, who say they never go to the gym yet have impressive physiques. This is because their bodies have adapted to the environment it frequently finds themselves in.
However, while most people understand this on a certain level, they often hit plateaus because they confuse going to the gym with building muscle just because they are lifting weights. The gym is nothing but an artificial environment where we place an artificial stress on the muscle to cause it to grow. That being said, if you go to the gym and continue to use the same weight, you are keeping your body in the same environment so your body won’t grow.
Therefore, in order to grow, you must continually place your body in a more stressful environment to adapt to, i.e. adding weight to the bar. In other words, simply going to the gym isn’t enough if you’re trying to build muscle. For progress to occur, you must always be aiming to place a larger stressor on your body overtime.
Best Exercises For Hypertrophy
There are a lot of exercises to choose from when training for muscle hypertrophy, and at the end of the day, technically, anything can build muscle. We are all aware of “farm strength” in guys who have never done anything except work on a farm. That being said, there are definitely some exercises that are better suited for hypertrophy.
Dumbbells > Barbell
We love the barbell and would never pack it away. However, there’s good reason to think that picking up a pair of dumbbells might be optimal when it comes to hypertrophy. Assuming the barbell and dumbbells utilize a similar movement, the dumbbells allow a greater range of motion as well as require more stabilization. Both of these can increase the stress on a muscle resulting in greater growth.
This would be applied mostly to your big upper-body compound exercises such as:
- Performing dumbbell shoulder press instead of military press
- Performing dumbbell chest press instead of barbell bench press
In fact, this was shown to be the case in a study that looked at using the barbell and dumbbells during the shoulder press during the seated and sitting position. The study found that the most activation was found in the standing dumbbell press and the least in the sitting barbell press3.
However, an inverted relationship was also seen with the load a lifter could use. In other words, the standing dumbbell press (most activation) allowed the least amount of load while the sitting barbell (least activation) allowed the greatest load. In fact, both seated versions allowed greater strength than the standing versions. Therefore, we don’t want you to get too caught up in muscle activation as it doesn’t necessarily equate to muscle growth.
However, since the loads tend to be close enough to not make much of a difference, using the dumbbells is likely better. (Again, we want to make a note that you can absolutely still build muscle with the barbell. We’re just referring to optimal training for muscle hypertrophy)
Use Cables For Isolation
When it comes to isolation exercises, we strongly prefer using the cable machine as it allows even force to be applied to the muscle throughout the movement. This is because the force load comes from the same direction regardless of where the handle is. Compare this to using a dumbbell, where the tension will increase the farther a joint is opened.
Therefore, stick to the cable machine for a lot of your isolation movements, such as cable flys for the chest or reverse flys. These allow a greater stretch with an even load across the whole range of motion. Still, it comes in very handy for exercises like the Bayesian Curl, which requires tension to be applied past 0-degrees.
From a practical standpoint, cables allow multiple abilities to enhance your workout:
- Quickly change weights for drop sets
- Alter the height to hit different angles
- Change implements quickly to switch exercises
- Use implements that you could not elsewhere, i.e., rope attachment.
All in all, we love the cable machine and use it for the vast majority of our smaller hypertrophy movements.
Variants Of The Same Exercise
We went over this some above but feel it’s important to list it here as well. Using slightly different variants of the same exercise is a great way to stimulate the same muscles, albeit slightly different. For example, this study showed that the deadlift and Romanian deadlift will hit the muscle fibers of the glutes, quadriceps, and hamstrings differently4.
From a practical side, this allows you to easily write out a plan for a prolonged period of time without having to actually rewrite the entire program.
Tempo And Training To Failure
We’re going to make this simple. Don’t stress too much about tempo assuming you perform your reps in a slow and controlled manner. While time under tension is important, altering the tempo with more finesse than a “slow” eccentric doesn’t seem to produce much of an impact.
However, you can also increase neuromuscular adaptations by producing a fast concentric contraction. This can translate into greater strength gains with your lighter weight. Keep in mind that your eccentric contraction is more responsible for muscle hypertrophy so you’re not going to really lose out by utilizing a fast concentric. That being said, your best tempo would be:
- Eccentric: Slow (2-3 seconds)
- Concentric: Fast (As powerful as possible)
Further, keep in mind that your sets need to be taken to near failure. This should happen anyways if you use the rep scheme suggested above. However, if for some reason you feel strong that day and are able to complete more reps, do it! This is where the meme “It’s the last reps that count!” comes from.
Don’t Forget Strength Training
Even though you may solely be interested in muscle hypertrophy, you should not completely eliminate strength training from your program. One interesting fact surrounding the hypertrophy and strength rep spectrum is that while you can build hypertrophy with heavier loads (>85%1RM), the same can’t be said for building strength with lighter loads (<80%1RM).
In other words, it seems that you must use heavier loads if you want to get stronger. Therefore, while you don’t need every exercise to be in the heavy range, you should use at least one major compound exercise for each movement pattern.
Below are the movement patterns and an exercise example:
- Upper Horizontal Pushing: Bench Press
- Upper Horizontal Pulling: Bent Over Row
- Upper Vertical Pushing: Military Press
- Upper Vertical Pulling: Chin-Up
- Squat: Back Squat
- Hip Hinge: Deadlift
You will NEVER be as big as you can be without including strength training. This is merely due to you not being able to produce as much volume. In addition, you’d likely miss out on some myofibrillar hypertrophy.
Proper Nutrition For Muscle Hypertrophy
After your hypertrophy training is done, you’re still not done. What you eat will play a huge factor in your muscle growth. Therefore, we’ll quickly go over some key guidelines to follow.
1) Be In A Caloric Surplus:
You need calories to eat. While some may argue that you can build muscle in maintenance mode or even a caloric deficit, muscle hypertrophy will be optimized when in a caloric surplus. This will give your body the energy it needs to rebuild your muscles.
However, keep in mind you can’t force-feed your muscles. Your muscles can only grow so much, so if you eat more than that, you will just add fat. Therefore, only get in a 300-500 caloric surplus to maximize muscle gain and minimize fat gain. For more guidance here, check out our 7 day meal plan for muscle gain.
2) Eat Enough Protein:
Muscles need protein to grow. Therefore, you do not want to short yourself. For optimal muscle growth, eat somewhere between 1.6-2.2g of protein per kilogram of body weight. Because you are in a caloric surplus, you can actually get away with the lower end of the spectrum if you desire. Keep in mind that this is your total daily protein intake.
3) Spread Your Protein Throughout The Day:
In order to keep your protein synthesis levels elevated evenly throughout the same day, aim to eat a serving of protein every 3-4 hours. Further, each serving should be at least 20g of protein to maximally stimulate muscle protein synthesis (MPS). While higher amounts will create a larger MPS, this seems to be the threshold where you stop getting the most bang for your buck. Determining the best timing for your protein shake can also help with muscle hypertrophy.
4) Don’t Follow A Low-Carb Diet:
We have nothing against keto or low-carb dieting; accept the fact they’ve been overblown. Regardless, we can say that they are not ideal if you are trying to get an increase in muscle mass. Multiple studies have shown that low-carb diets result in less than optimal muscle growth, if any5. If you want to use a low-carb diet once you reach your optimal muscle size, then we’d say go for it as they may be beneficial for muscle retention. Keep in mind, though, that in order to refuel your energy stores, you'll always want to include carbs in your post-workout meal.
Supplements And Special Nutrition Variables For Skeletal Muscle Mass
Last, here are some supplements to include along with special nutrition topics:
- Creatine: Creatine is, without a doubt, the most effective nutrition supplement on the market. If you’re not taking it, you’re doing it wrong. Creatine will definitely add lean body mass, so use it if you want to build muscle. In fact, research shows that creatine causes weight gain in the form of additional muscle mass, making it a great supplement to take when muscle hypertrophy is your goal.
- Pre-Workouts: Pre-workouts are a great way to give yourself a boost of energy and stamina at the gym. While they may not be as effective as creatine, they can definitely provide the energy needed to add the extra volume needed for muscle hypertrophy.
- Pre-Sleep Protein: A relatively new area of research that shows promise is pre-sleep protein. Multiple studies have shown that taking 30-40g of casein protein (emphasis on casein protein) 30 minutes before bed can increase the recovery from resistance training. While more research needs to be done, there’s a good chance this would lead to greater muscle hypertrophy.
- Post-Exercise Meal: The post-exercise meal is one of the most misunderstood aspects of fitness. Some incorrectly say it means everything to your training, and if you miss it, you’ve wasted your time at the gym. Others will try to correct this and overstate that your post-exercise meal doesn’t mean anything.
In reality, the truth likely lies in the middle somewhere. While your total macro intake is most important, next comes food timing and then your post-exercise meal. The best way to think about your post-exercise meal is if you can have one, don’t put it off. At the same time, you don’t need to run red lights to get to the nearest protein source.
Your post-exercise meal should contain 0.25g/kg of body weight and a 1:2-1:3 protein to carb ratio. In addition, be sure to rehydrate yourself.
Sleep And Recovery for Skeletal Muscle Growth
We won’t spend a lot of time here, but if you’re not getting adequate amounts of sleep, you’re shooting yourself in the foot. In fact, watching their clients mess up sleep may be the most frustrating part a coach or fitness trainer witnesses.
Sleep is easily the most important tool for recovery we have, and it can make a dramatic impact on your muscle growth. Further, it’s the easiest thing to do as all you do is sleep. We understand people are busy with family, business, and a social life, but understand that sleep is vital to not only muscle growth, but general health as well.
And, as you age, the more important it becomes. Check out our Muscle Building Workout Plan For Men In Their 40s to learn more about this.
Muscle Hypertrophy: Recap
Human skeletal muscle gain doesn’t need to be as complex as it sounds or as many try to make it out to be. Here is a recap of everything you need to know:
- The majority of your work should be in the moderate rep range (8-12) using moderate weights (70-85%1RM).
- Stick with your normal, basic exercises. Then, alter these exercises slightly to add variety.
- Use dumbbells for your compound hypertrophy movements.
- Use the cable machine for your isolation movements when possible.
- Train each set to near failure.
- Eat enough protein daily (1.6-2.2g kg).
- Spread out your protein intake throughout the day every 3-4 hours.
- Eat your carbs.
- Get 6-9 hours of sleep every night.
- Creatine is your best friend!
- Don't stop working out, muscle atrophy (muscle loss) is a lot easier than muscle hypertrophy.
Other than that, it’s just consistency. Most people give up because they expect too much too soon. Promoting muscle growth is a slow process and muscle hypertrophy occurs if you follow the correct steps. Therefore, be consistent with your training and nutrition if you want to build muscle mass! It takes weeks and weeks of resistance training, but muscular growth will occur.
Looking for a great workout that promotes muscle growth? Check out our 5-Day Hypertrophy Workout Plan.
Prepare to maximize your gains with our exclusive 12-week hypertrophy training program. Choose between a 4 or 5 day training split and gain 2-12 pounds of muscle over 90 days...
References:
- Figueiredo VC, de Salles BF, Trajano GS. Volume for Muscle Hypertrophy and Health Outcomes: The Most Effective Variable in Resistance Training. Sports Medicine. 2017;48(3):499-505. doi:10.1007/s40279-017-0793-0
- Zabaleta-Korta, Aitor MSc; Fernández-Peña, Eneko PhD; Santos-Concejero, Jordan PhD, FECSS. Regional Hypertrophy, the Inhomogeneous Muscle Growth: A Systematic Review. Strength and Conditioning Journal 42(5):p 94-101, October 2020. | DOI: 10.1519/SSC.0000000000000574
- Saeterbakken AH, Fimland MS. Effects of Body Position and Loading Modality on Muscle Activity and Strength in Shoulder Presses. Journal of Strength and Conditioning Research. 2013;27(7):1824-1831. doi:10.1519/jsc.0b013e318276b873
- Martín-Fuentes I, Oliva-Lozano JM, Muyor JM. Electromyographic activity in deadlift exercise and its variants. A systematic review. PLoS ONE. 2020;15(2). doi:10.1371/journal.pone.0229507
- Paoli A, Cancellara P, Pompei P, Moro T. Ketogenic Diet and Skeletal Muscle Hypertrophy: a Frenemy Relationship? Journal of Human Kinetics. 2019;68(1):233-247. doi:10.2478/hukin-2019-0071
Garett Reid
Author