People use the internet to find answers. When it comes to information on how to build muscle, the web is full of misinformation.
My goal is to lay it all out so you have a full understanding of:
- How the body builds muscle
- Why the body builds muscle
- Which exercises and workout methods build the most muscle
- How to eat and what supplements to take to build muscle
Note: This article contains affiliate links. Only products we've deemed valuable are listed, and are at no additional cost to you.
How Does the Body Build Muscle?
There are about 650 skeletal muscles in the human body. Muscles are made up of tubular muscle cells called muscle fibers. These in turn are made up of myofibrils and sarcomeres. Filaments within the sarcomeres slide against each other, contracting the muscle and pulling our bones, which we would commonly call "movement."
The body is believed to be able to build muscle 2 ways:
1. Muscle Hypertrophy
Hypertrophy is the increase in size of the muscle fibers. This can happen by increasing the diameter of the muscle fiber, or the length of the sarcomeres.
What Causes Muscle Hypertrophy?
- Mechanical Tension: Lifting weights creates tension within the muscle tissue. This tension is detected by sensors within the muscle, triggering events that lead to increased protein synthesis.
- Metabolic Stress: Think of the burning sensation you feel when you do a set of high reps. This is metabolic stress, caused by the accumulation of lactate and other metabolites in the muscle. The environment created by metabolic stress signals increased protein synthesis (and tends to give you a "pump.")
- Muscle Damage: It has not been conclusively shown that muscles grow due to damage incurred during a workout. In theory at least, muscle fibers damaged from an intense workout would signal increased protein synthesis. They would then be rebuilt bigger and stronger. Studies have not shown this to be true.
Hypertrophy is an increase in size of the muscle fibers you already have. It does not mean you've added new muscle fibers.
2. Muscle Hyperplasia
Hyperplasia means the addition of new muscle fibers. Whether or not this is even possible in humans is a subject of great debate. There are conflicting studies and no conclusive evidence that we can actually create new muscle fibers as a result of physical training. (without drugs).
Even if it is possible, it is not the primary way we build muscle from exercise and weight lifting. When we work out in a specific way, we trigger a series of events that lead to increased protein synthesis, causing hypertrophy of our muscle tissue.
Why Does the Body Build Muscle?
Our bodies do not build muscle so that we can look good at the beach. Bigger, stronger muscles are built gradually in response to repeated stress being placed on the body.
Bigger muscles are essentially an adaptation to stress. In order to continue building muscle, new and more challenging forms of stress (exercise) must continuously be applied. This can mean heavier weight, more reps or new exercises.
In short, our body will build muscle when it is forced to do so by the repeated demands placed on it, and when it has the extra resources to do so. It takes a lot of energy (calories) to maintain and especially to build new muscle. For this reason, a caloric surplus is necessary.
Now we need to get into more practical topics and how you can apply this knowledge to your own workouts to build muscle.
What Causes the Muscle to Grow?
It's important to understand that it is the environment within the muscle that signals increased protein synthesis (muscle growth). When we work out in a specific way, we purposefully create an intramuscular environment that will allow us to build that muscle.
Remember we said that muscle hypertrophy is caused by mechanical tension and/or metabolic stress. (we're leaving out "muscle damage" as it is not clear that this actually causes hypertrophy.)
When we lift weights, we create tension within the muscle as it contracts and stretches. Think of a biceps curl. The biceps contracts, pulling the load up, then stretches as you lower the weight back to the starting position.
There are 2 important points to understand about tension as it relates to building muscle:
1. Greater tension results in more muscle growth
When we lift heavier weight, we lift it more slowly. This causes more high-threshold motor units (muscle fibers) to be recruited. The same phenomenon can be seen during the eccentric phase of a lift. Slowly lowering the weight in a biceps curl causes much greater tension in the muscle than the concentric portion of the lift.
This is why bodybuilders have always focused a lot on the eccentric portion of their lifts.
Practically, this means 2 things:
- Lifting heavier weights, in the 1-5 rep range, will cause greater tension than lighter weights. You'll recruit more high threshold motor units.
- Focusing on the eccentric portion of the lift will cause more tension, again recruiting more muscle fibers. Take note that this also causes a lot of additional stress to the body, and can quickly lead to overtraining and fatigue. It's a tool, not something you have to do all the time. It's also not necessary for growth. Again, just a tool.
2. Fatigue and muscle growth
When you perform multiple sets, the muscle will become fatigued. When the muscle is fatigued, the muscle fibers being recruited will not be able to keep up. As a result, additional muscle fibers will be used to continue lifting the weight.
For this reason, programs using schemes like 5 sets of 5 reps are very effective. They create a high amount of tension using relatively heavy weight, and also involve fatigue as you get to the 4th and 5th sets.
Imagine doing a set of high rep squats, let's say 20 reps with moderately heavy weight. At the end of that set, your legs (and entire body) would be begging for mercy. That feeling is caused by metabolic stress.
Lactate and other metabolites have accumulated in the blood and within the muscle, causing an acidic environment and making muscular contractions more difficult.
You'd also likely have a pretty good "pump," in your legs caused by blood and plasma being shuttled into the muscle and volumizing (expanding) cells.
This environment caused by metabolic stress sends a powerful signal for muscle growth, given the load being used is adequate, generally at least 60% of your 1 rep max or greater. Anabolic hormones like testosterone and growth hormone are increased, as is protein synthesis.
Which Workout Methods are Best to Build Muscle?
We've already discussed that the type of workout you perform places specific stress on the body, forcing it to adapt by building muscle.
More specifically, we learned that the type of workout we do creates a specific environment within the body and muscle, which signals increased protein synthesis and muscle growth.
So what type of workout is optimal for building muscle?
High Reps (12-15)
Training with high reps (more than 12) has been shown to be less effective at building muscle than lower rep ranges.
This is probably because the lighter weight used simply cannot recruit the highest threshold (most powerful) motor units. Using less than 60% of your max does not create adequate tension in the muscle to signal growth.
Using these rep ranges will lead to muscle endurance and possibly a small amount of growth due to metabolic stress.
Blood Flow Restriction Training (BFR)
An exception to this would be if you're using occlusion training, which involves using bands around your arms or legs to restrict blood flow.
BFR training has been scientifically shown to increase muscle growth and strength when using high-rep/light weight training.
Low Rep/Heavy Weight (1-5 reps)
There's no disputing that using a low rep/heavy weight strategy can build muscle. 5 x 5 and other similar programs have been used by some of the best bodybuilders, including Arnold Schwarzenegger and Reg Park.
Generally, lower reps and heavy weight lifting is optimal for gains in strength. By lifting heavy weights in the 1-5 rep range, you're training the nervous system to recruit more muscle fibers, making you stronger.
What's somewhat lacking in the lower rep ranges is the metabolic stress necessary for optimal muscle growth. With low reps, the body relies almost entirely on stored energy (phosphocreatine) to complete the lifts.
This causes you to need longer rest periods (2-5 minutes) in order for your body to replenish that energy, which results in less metabolic stress in the muscle. You cannot shorten your rest period without limiting your performance.
The Optimal Muscle Building Range
Research has shown that the 6-12 rep range with moderately heavy weights is the optimal style for building muscle.
Training in the 6-12 rep range forces the body to rely on anaerobic glycolysis for energy. This means the body must use glucose, which is then converted into lactate. This causes the buildup of lactate and other metabolites in the muscle. You'll remember that we defined this as metabolic stress, which causes muscle hypertrophy.
The result of this increased metabolic stress is increased testosterone and growth hormone production and increased protein synthesis post-workout. Not to mention a huge pump, which is also thought to promote muscle growth.
Training in the 6-12 rep range with moderately heavy weight and relatively short rest (1-2 minutes) results in the most anabolic environment in the body. This means it will send the strongest signal to increase protein synthesis and build muscle.
Which Exercises are Best to Build Muscle?
It is widely accepted that for muscle growth, the big, compound exercises are superior for building muscle. While people still debate this, there is really no question about it.
Big, compound movements like the deadlift, squat and overhead press use several different muscle groups in unison. This results in:
- Moving more weight
- Using more total muscle
- A greater anabolic response:
- Greater testosterone and growth hormone production
Most bodybuilders and powerlifters would tell you that big, compound movements are superior for both size and strength. These lifts include:
- Standing Overhead Press
- Bench Press
- Pull up/Chin up
- Barbell Rows
Workouts should generally start with big lifts, and end with isolation type lifts. Prioritize the most important and beneficial exercises at the beginning, when you have the most strength and energy.
The Importance of Getting Stronger
People often don't prioritize getting stronger. The problem with that is that you'll eventually plateau and your body will require heavier weight in order to grow. At that point, if you don't get stronger, you're probably not getting any bigger.
Remember why the body builds muscle. It's an adaptation to stress. You have to continue increasing that stress over time in order to continue growing.
If you increase your bench press by 30 pounds, you can then perform every rep of your workout with heavier weight. This would result in additional (new) stress on the muscle, which would result in growth.
Periodizing Your Training
Since strength is so important, it is critical that you switch up your training periodically to focus on getting stronger. Just because the 6-12 rep range is optimal for building muscle, that doesn't mean you should work out ONLY in that range.
It'd be far more productive to do something like this:
|6-12 rep range
|5 x 5 (or similar)
Periodizing your training doesn't mean you have to completely abandon gaining muscle in order to get stronger. You simply need to shift your focus a bit to keep the body responding and adapting. 6 weeks of strength training can allow you to come back into another hypertrophy cycle stronger.
Your nutrition strategy is paramount when trying to build muscle. One of the most basic tenets of building mass is that you must maintain a positive energy balance. This means eating calories in excess of what you need to maintain your current size.
Without extra resources, your body cannot and will not build muscle. Building and maintaining muscle requires a lot of resources, and our bodies will place those resources elsewhere unless we maintain a surplus.
How Many Calories Do You Need To Build Muscle?
This varies from person to person. It's helpful to know your body, and you will in time by trial and error. A simple equation to get a rough idea of how many calories/day you'll need to build muscle and gain size is:
- Multiply your weight in pounds by 18.1
- Multiply your weight in kg by 40
So, if I weigh 220 pounds, I'd need around 4,000 calories/day to gain weight.
How Much Protein Do You Need To Build Muscle?
If you're working out and creating an anabolic environment in the body, it's crucial to have enough protein available throughout the day to allow your body to build muscle.
Contrary to popular belief, you do not need 1 gram of protein per pound of body weight, unless you're taking anabolic steroids. Multiple studies have found no additional benefit to consuming more than 0.7 grams/pound of body weight. Several studies showed that even less than this is adequate to build muscle.
It's also a myth that the body can only digest 30g of protein from each meal. When eaten along with other macronutrients like carbs and fats, it can take a lot longer to digest protein. Therefore, more than 30g can be utilized over several hours from a big meal.
Generally, as long as you're getting an adequate amount each day spread out over 4-6 meals, you should be fine.
Pre Workout Nutrition
Eating a meal high in carbohydrate and protein 60-90 minutes before your workout can have a positive impact on muscle growth and workout recovery. Studies have shown that pre-workout consumption of protein can have the same effect on muscle growth as post workout consumption.
Consuming carbohydrate and protein before a workout can result in faster glycogen replenishing and increased protein synthesis, speeding up recovery and helping to build muscle.
While supplements can definitely help build muscle, the majority of them are nothing more than placebo-pills. There are a handful of supplements that have been shown to have measurable effects on muscle building:
- Creatine: Creatine is basically stored energy in your cells used for high intensity effort like a heavy lift or a short sprint. Supplementing creatine saturates the muscle, potentially allowing you to get extra reps with heavy weight.
- L-Citrulline: Converts to nitric oxide in the body. Increases blood flow by dilating blood vessels. Increases "pump." 6 grams is necessary for the full benefit.
- L-Carnitine: Controversial fat-loss benefits, can also increase androgen receptors, which bind to testosterone.. helping build muscle.
- BCAA's: If your pre and post workout nutrition are on point, you have no need to use BCAA supplements. In the absence of a pre- workout meal, use 5-10 grams of BCAA's during your workout.
Getting Calories From the Blender
It can be hard to get enough calories to build muscle every day from your diet. For this reason, the blender can be your best friend. Using whey protein, fruit, peanut butter and whatever else you like, you can get a huge amount of calories and protein quickly.
Here's one smoothie I've used for years:
Prioritizing recovery is just as important as any training or diet consideration. We don't build muscles while we're at the gym, we build them when we're resting and sleeping.
Muscle growth occurs when we're not training. That means on days away from the gym. Spending too much time at the gym or doing too much high intensity training can flood your body with catabolic stress hormones like cortisol. This results in many undesirable effects, including muscle wasting.
Make sure to prioritize days away from the gym. Getting a massage has been shown by research to speed up recovery. Other activities like playing a video game, watching a movie, or anything relaxing can also have a beneficial impact on allowing your body to recover and regenerate (and build more muscle).
Limit Conditioning and Cardio
Too many people out there are trying to achieve multiple goals at the same time. They want to get bigger, get stronger, lose weight, get leaner, get faster... I digress.
Attempting to build muscle, then going and performing an hour of intense cardio will cause interference. You're giving your body mixed signals based on the the environment you're creating in your body.
In order to build muscle, you must maintain a caloric surplus and create the most anabolic environment possible. Excessive cardio will pull energy away from building muscle, spending it instead on your cardio sessions and especially on recovering from them.
Will that 5 mile run hurt your muscle gains? Yes. Is it worth it? That's really up to you and your priorities.
In short, don't ignore your cardiovascular training and health. Just don't overdo it. If your priority is building muscle, then focus on building muscle. You can't do it all at the same time. The human body just isn't designed that way and you'll only hurt your gains.
Better Cardio Options For Muscle Building
There are some forms of cardio that are complimentary for those trying to get bigger and stronger. Here are a few examples below. You want to limit activities with a strong eccentric component. This will make them easier to recover from. Here are some activities you can hit fast and hard.
- Sled push/pull: Push a prowler/sled. Rest. Repeat.
- Hill Sprints. Sprint 30 seconds, walk 30 seconds. Repeat desired reps. Go home with tail between legs.
- Assault bike intervals. Max effort for 15 seconds, slow effort for 45 seconds. Repeat for 10-20 minutes.
It's important to include some cardio in your weekly split. Aerobic fitness can help you recover faster, and has too many health benefits for me to list here. In short, do some cardio, but stick to methods that are complimentary to your primary goals, and keep it fast and furious.
Related: 10 Ways to Boost Your Recovery
Building muscle can be a lot of work. But if it was easy, everyone would do it!
To build muscle, you need to maintain a caloric surplus and apply stress to the body that increases over time (progressive overload). To maximize muscle gain, we should use compound movements to elicit the greatest anabolic response from the body.
We should aim for the 6-12 rep range using moderately heavy weight, which gives us the most balance between mechanical tension and metabolic stress, creating the best possible environment for muscle growth.
You should always have en eye on getting stronger, and should make sure you're getting adequate calories and protein to keep the body building muscle all day long.
Lastly, we have to make sure we prioritize recovery. Muscle is built while we're resting. Relax, play some video games. Watch some netflix.
I hope this article was helpful, and as always, I hope it helped in some way to get you a little closer to that best version of you!