How Muscle Growth Works

Lindsay Nelson ~ Miss Alaska
5 min readJan 25, 2021


Now you have the gym, it’s time to learn how to use all that equipment in order to start triggering some serious growth. How to you get muscle to grow? How can you do this from the comfort of your own home with none of the hep or guidance you would get by working out in a real gym?

Let’s take a look…

The Basics

In order to build muscle, you need to trigger hypertrophy. This is simply the technical term for muscle growth and it actually occurs when you’re resting. This makes muscle building a ‘two-part’ process. Part one is the exercise that breaks down the muscle and marks it for growth and part two is the growth stage that occurs after you’ve finished lifting when you’re at rest.

This can occur through two separate methods. These are:

Myofibrillar Hypertrophy

Sarcoplasmic Hypertrophy

The precise science behind these principles is still something that is being argued and there are those that deny that these are accurate descriptions. However, ask any bodybuilder and they’ll tell you that broadly there are two ways to build muscle that seemingly correlate with these concepts.

Those two ways are:

Muscle Damage


Metabolic Stress

On top of that you have something else at play, which is the ability to build strength. Strength is often but not always related to muscle size.

The other factor that is involved then and that you need to account for is:

Muscle Fiber Recruitment

Okay. So that’s a lot of words I just threw at you. What does any of it mean? Simply put, your muscles are made up of lots of tiny strands called muscle fibers. These are actually cells, just like the cells that make up the rest of your body and the neurons that make up your brain. That means that they have nuclei and it means that they have sarcoplasm (if you remember enough of your high school biology).

The difference is that muscle fibers have multiple nuclei and they also have the ability to telescope in order to contract and expand. Of course when this happens en-masse, it causes your muscles to contract and expand too, which is how you lift things in the gym.

Unfortunately, there is no way you can create more muscle fibers. This is known as ‘hyperplasia’ and has only been known to occur under very rare circumstances. However, what you can do is to break down the muscle in order to make it grow back thicker.

You do this by lifting heavy weights to failure and especially under stretch, at which point you create ‘microtears’ in the muscle. Proteins are then used to repair those tears, which is what causes the muscles to come back larger. This is also what causes ‘DOMS’ — delayed onset muscle soreness. This is why you might find it hard to lift a mug of coffee the next day.

This is what we call myofibrillar hypertrophy and muscle damage. The most important factor here is to overload the muscle. There are other factors too though — such as making sure that you train the muscles from multiple angles to hit every fiber and training with both fast and slow form in order to train the fast twitch and slow twitch fibers.

Fast twitch fibers only kick in when the slow twitch fibers aren’t capable of lifting — and these are naturally the thickest and strongest types of fibers in your muscles. This is why you need at least a certain amount of weight in order to recruit them.

So what does sarcoplasmic hypertrophy involve? Well, this is muscle growth caused by swelling the muscles with fluids. When you lift for long enough, you gradually pump the muscles with blood and use up your lactic acid systems, filling them with those chemicals too.

In other words, the part of your body that is working will start to become swollen with blood, nutrients, oxygen and energy. And if you keep on lifting, this causes that part of the muscle to become fuller and fuller and ‘occludes’ the area (like wrapping a tourniquet around it).

Now the good news is that all this also triggers the release of metabolites — chemicals that trigger growth such as growth hormone and testosterone. At the same time, the muscles become more efficient at storing sarcoplasm and glycogen in order to perform for long durations.

This creates a more ‘puffy’ looking muscle that can perform for longer, rather than a harder and leaner muscle that can generate more short-term power. So this is sarcoplasmic hypertrophy and it is caused predominantly by metabolic stress. The key factor in bringing this about is time under tension and it will lead to that feeling of pump in the gym.

Both types are useful and when you combine both forms of training, you can build more size and power. As a general rule, bodybuilders tend to train more with sarcoplasmic methods, whereas powerlifters use more myofibrillar approaches. Then there are those that say there can be no such thing as sarcoplasmic hypertrophy. It doesn’t matter.

Think of this just as a useful cognitive tool for understanding the process. At the end of the day, bodybuilders know that lifting heavy for small reps equates to more power, while lifting lighter for high reps equates to STRENGTH. Combining both is ‘powerbuilding’.

Finally, there is one more concept we need to recognize here: muscle fiber recruitment. Because if you look at someone like Bruce Lee, you’ll see that it is possible to be immensely strong without having to have a lot of muscle size. How? By using a higher percentage of your muscle fiber in every movement. Bruce Lee was the master of this but there are a number of ways you can train to gain more control over your muscle fiber.

The main key is to train at the very highest end of what you’re capable of resistance wise. This forces your body to recruit as many of the fastest twitch fibers in the muscle as possible, which strengthens the ‘neuromuscular junction’ to increase your raw power output. Bruce Lee would even use a technique called static contraction, where he would push or pull against an immovable force to practice generating as much power as possible.

Add this to your routine and you’ll become even more deadly.



Lindsay Nelson ~ Miss Alaska

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