The 3 Laws of Muscle Activation in Resistance Training

The 3 Laws of Muscle Activation in Resistance Training:

Mechanical Tension = Strength (Strength = Mechanical Tension)

Muscle Damage = Injury (Injury = Muscle Damage)

Stress= Fatigue (Fatigue = Muscle Damage)

These are some basic laws which have been proven time and again to be true. They are very simple yet they apply to all types of resistance training programs. These three laws are often overlooked but they do play a major role in your physical fitness goals.

If you want to build bigger muscles and get stronger, then these three laws will definitely help you achieve it.

If you don’t like them, then why not?

You decide what works best for you! But if you follow these rules, then your body will respond well to any type of exercise routine and your results will be better than with other methods.

Let’s take a look at each law one by one.


Mechanical tension refers to the fact that when you use heavy weights, your muscles will become sore and damaged. The reason why this happens is because the weight used in resistance training causes damage to your muscles. However, you need to remember that there are two ways of getting rid of pain; either through rest or through painkillers. For example, when you get a cut in your skin, you must rest or take painkillers. The same concept applies to lifting weights; you can either rest or use painkillers (which are heavy weights).

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When training for hypertrophy, it is important to take mechanical tension into consideration. The more mechanical tension you put your muscles under during a training session, the more you will break down the muscle tissue and the bigger the muscles will grow. If you do not break down the muscle tissue through heavier weights, then your muscles will not be forced to adapt and they will not grow.

The more resistant training you put your muscles under, the more mechanical tension you will cause and the bigger the muscle will grow. Another phrase for this is “No Pain, No Gain.” You can also use the pain and discomfort of your muscles as an indication of how well you are training your body.

Let’s take a look at the different types of mechanical tension in regards to resistance training:

1. Eccentric Tension- This is the tension that is placed on a muscle while it is lengthening during the lowering phase of a movement.

2. Concentric Tension- This is the tension that occurs in a muscle while it shortens during the lifting phase of a movement.

3. Isometric Tension- This is tension that occurs in a muscle while it is being put under tension but not shortened or lengthened in any way.

The more of these three types of tension you place on your muscles, the more they will grow. There are two major ways to increase this form of mechanical tension:

1. Increase the weight you are lifting.

2. Increase the amount of time the muscle is placed under tension.

So, let’s say you are doing a set of chin-ups and you can do five reps. Each rep consists of raising your bodyweight a few inches off of the floor and then lowering yourself back down again so that your arms are fully extended, making a “U” shape. Now, if you hold the bottom position (arms fully extended) for ten seconds before doing your next rep, you will have placed more mechanical tension on the muscle and it will grow more.

So, where does the “No Pain, No Gain” come in?

Well, if you do not take painkillers or rest for the soreness that will result from increasing mechanical tension over a period of time, then you will not grow as well. For example, if you continue to do the same set of chin-ups described above, your bicep muscles will begin to burn and might become sore after a week or two. The longer you hold the bottom position, the more they will burn and be forced to grow and adapt to the increased tension placed on them.

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As you can see, both painkillers and rest play an important role in skeletal muscle growth. Without painkillers, you will not be able to train as heavy or hard for fear of the soreness that would result. You need to take a break after your muscles begin to burn so that you can continue to break down the muscle and make it grow bigger and stronger as it heals.

Without rest, the body doesn’t have time to heal the micro-tears in the muscles that occur during training. This leads us into our next section: Muscle Fiber Types.

Muscle Fiber Types

Skeletal muscles are made up of several hundred million cells wrapped in a protein fiber called myofibril. These cells can have different shapes and properties but for the sake of our discussion we are going to focus on two types, Type I and Type II fibers.

For the most part, skeletal muscles are made up almost entirely of Type I fibers. These fibers are considered “Type I” because they contain a large amount of myosin protein. “Fast” or “Power” fibers are considered Type I. They contain a large amount of glycogen and are good for short, quick movements.

Type II fibers contain a smaller amount of myosin and are known as “Endurance” fibers. They are used for longer periods of time and rely on fat metabolism for energy. They contain a larger number of mitochondria to provide the energy for long periods of time. These are the “slow-twitch” fibers which are good for things like long distance running.

Other Types of Fibers

While most skeletal muscles are made up of both slow and fast fibers, each muscle can have a varying mixture of the two types of fibers. For example, leg muscles like the quadriceps (thigh) are almost entirely made up of fast twitch fibers which are good for powerful, quick movements. Back muscles like the Latissimus Dorsi are made up mostly of slow twitch fibers which are good for things like holding something heavy over your head for a long period of time without tiring.

So, we know that Type I fibers are used for short bursts of power and Type II are used over long periods of endurance.

What about the other types?

Type IIA fibers are a mixture of type I and type II fibers. They have some characteristics of both.

Type IIAX fibers are entirely made up of type I fibers. While they do contain small amounts of myosin, they rely more on another protein calledactin for their long term energy needs.

Type IIX fibers are entirely made up of type II fibers. While they do contain small amounts of myosin, they rely more on another protein calledactin for their short term energy needs.

So what does all this mean?

Well, it means that whether you are a hard gainer or a easy gainer has everything to do with your individual muscle fiber type.

Someone with a high percentage of type I fibers (type I mostly) will have an easier time gaining size and strength in the gym than someone with a greater percentage of type II (type II mostly).

How can you tell what type of fiber you have?

There are a couple of ways: One way is through this nifty little device called an “electromyograph”. This measures the electrical activity of your muscles while at rest and can tell you if you have more fast or slow fibers. The problem with this is that it’s very expensive and requires expert handling. In other words, unless you have easy access to one, it’s not going to do you any good.

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The second, and much easier way is through a simple muscle biopsy. This takes a tiny sample of muscle tissue from your body and examines it under a microscope. While slightly invasive, it can easily be done by a doctor and will give you your muscle fiber type ratio with ease.

So now that we’ve covered the different types of muscle fibers, let’s take a look at how we can change them.

How to Change Your Muscle Fiber Type

Having the right mixture of muscle fibers is essential to your goals in the gym. Whether you want to get bigger, stronger or just look good, you’re going to need the right muscles working together.

But what if you’re lacking in certain areas? Is it possible to change your muscle fiber type from one type to another? And if so, how would you go about doing it?

Let’s take a look.

Changing Your Muscle Fiber Types isn’t Easy

Now I hate to be the bearer of bad news, but if you’ve been reading up to this point and thought that all you had to do is lift heavy things and you’ll suddenly have lots of big, powerful muscle fibers, then I’m afraid you’re wrong. Changing your muscle fiber type is near impossible.

Don’t believe me?

Well, it’s all to do with something called “muscle memory”.

Ever watched a professional weightlifter move his limbs and thought how fluid and quick they are despite being much heavier than you?

Well that’s because their nervous system is accustomed to moving their heavy limbs which in turn has strengthened the connectors from the nerves to the muscles, hence “muscle memory”.

This happens with any activity you do often.

Ever forgotten how to do something that you once could easily, like riding a bike or typing?

Yep, that’s “muscle memory” at play.

Now while this is a good thing in general as it helps us perform the activities we do often more easily, it unfortunately limits how our muscles can develop. In fact, it makes it near impossible to change your muscle fiber type because the myosin and actin filaments that are inside each muscle fiber are the main thing that make them contract in the first place!

There is some good news though. It’s been shown that you can modify the size and strength of your specific muscles by doing the right exercises, which we’ll talk about shortly. This is more important than you think as having strong and developed muscles will help prevent injury when lifting and improve your posture.

But I’m here to tell you how to turn yourself into the hulk, not give health and safety warnings! So without any more delays, let’s look at how you can change your muscle fiber types.

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How to Turn Slow Fibers into Fast Fibers and Vice Versa

If you’ve been living under a rock for your whole life and don’t know what I’m talking about, then the fast and slow twitch fibers are what determines how quickly your muscles contract and fatigue.

Type 2 – These are the fastest fibers but don’t last very long during strenuous activity. Typically, these are the smallest fibers in your muscles and are used for things like running very quickly or jumping.

Type 1 – These are a lot slower than type 2 fibers but can last a lot longer, hence why they’re used in steadying heavy objects or holding poses, such as in yoga.

Converting these types of fibers isn’t too hard. I’ll be honest, it’s not going to be a quick process and it’s going to take dedication, but if you want to change your muscular structure, then there’s no other way.

Here’s how you start changing your muscle fiber types.

How to Develop Fast Twitch Muscle Fibers

If you want to turn your type 2 fibers into type 1, then you need to start doing slow movements with heavy weights. So for this you need to focus on exercises that involve slow and controlled movement with heavy weights.

These include exercises such as the leg extension, leg curl, chest press, shoulder press and even things like the back row. Focus on lifting slowly and really feel the burn when you reach your stopping point.

The theory is that these exercises will start to make your type 2 muscle fibers work in a similar way to the slow-controlled movements that trains the type 1 fibers. Over time, this will ‘switch on’ the genes needed to make the change from type 2 to type 1.

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Now you might be wondering why you should bother.

Why would you want to make your muscles slow?

It’s true that having fast twitch muscles do give you some advantages especially in things like sprinting, but it isn’t everything.

Take for example the marathon runner and the powerlifter. Both are extremes, but they both require their muscles to work slowly and controled for long periods of time. In a way, by turning your muscles into slow twitch fibers you’ll be training your body for endurance which is useful for so much more than just lifting weights.

So you might be thinking that this sounds pretty good so far, but there are some big drawbacks. The main one being the fact that it can take many months before you even start seeing results from this training style.

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