Muscles: How Do They Grow?

Hey everyone!

Welcome back, or welcome to the page.muscle hypertrophy

In the last post, I spoke in detail about muscles: the types, the shapes, what they do, and why it is important to have them. I also briefly talked about how muscles grow, with the promise of an in-depth look at that process.

Well, here it is!

Let’s get started.

Muscle Hypertrophy

Muscle growth, or hypertrophy, occurs after you work out; that is, after you have stressed the muscles by exposing them to a load that they have not lifted before, or is difficult to perform. The muscles will do the work, but the growth occurs after the workout, while you are resting the muscles.

muscle hypertrophy

Let me explain.

In order for muscles to grow, two things need to happen. First, there needs to be stimulation. This stimulation of the muscles occurs when a signal is sent from the nervous system to contract the muscle. This is the actual exercising of the muscle. If you are performing a bench press, your nervous system will send the appropriate signal to the appropriate muscle telling it to contract to lower and then lift the weight.

In the beginning stages of weight lifting, this constant activation and stimulation causes an increase in strength, and may not cause an increase in the size of the muscle. That is not a bad thing, as the muscles need to get stronger so they can lift progressively heavier weight. This progression of weight will cause the muscles to grow.

A note here. When you work out, your muscles will instantly look bigger. This is not due to muscle growth, but due to the increased blood flow to the muscle. This is the “pump” that weight lifters often talk about.muscle pump

Also, since we are mostly water (cucumbers with feelings), we need to remember to hydrate ourselves properly at all times. This will allow our muscle cells to have the proper amount of water, and they will look bigger all the time.

The second component of muscle growth is repair. Now that we have stimulated the muscle and worked out by lifting a weight that was heavy enough to be difficult, the muscle has been damaged. This is not permanent damage. It is damage that is necessary for the muscle to grow. During repair is where the growth occurs. That is why resting your muscles is essential for growth.

After you work out, your body repairs (or replaces) the damaged muscle fibers using a cellular process where it fuses muscle fibers together to form new muscle proteins or myofibrils (myofibril hypertrophy). These repaired myofibrils are increased in number and thickness, therefore causing hypertrophy (growth). Muscle growth can only occur when the rate of muscle protein synthesis is greater than the rate of muscle protein breakdown.

This occurs during rest and is fed by the proteins in your body, so rest and proper nutrition (an article for another day) are essential for muscle growth.

Stimulating Hypertrophy

So that was a bit of science to explain how the muscles grow. We need to stimulate them, which will break them down, and then we need to rest them, so they can repair and grow.

So, how do we stimulate growth? There are three specific ways to do that.progressive overload

The first is tension. In order to stimulate the growth of the muscles, we need to subject them to progressive overload – we need to increase the amount of weight we are lifting over time, increase the number of reps we are doing, increase the number of sets we are performing, increase the time the muscles are under tension, shorten the rest periods, or increase the training frequency. This throws our muscles out of equilibrium, and they break down at a faster rate, allowing more growth during rest and repair.

Muscle damage is the next factor. You do not necessarily need to feel sore when you are finished a workout, but you will probably have muscle soreness the next day. That is a good thing, as it will trigger the immune system to activate the cells necessary to repair the damage and cause the muscle to grow.

The third mechanism that causes muscle hypertrophy is metabolic stress. I mentioned the “burn” a little earlier. This is metabolic stress. By causing more blood to flow through the muscle, we cause hypertrophy of the connective tissue cells, as opposed to the muscle cells. With the added glycogen, everything swells and grows. This is known as sarcoplasmic hypertrophy, where the muscle grows larger, but not necessarily stronger.muscle growth factors

All three of these factors contribute to muscle growth in their own way. Each is equally important and vital in the growth of our muscles. Luckily, we do not have to think about these things to make them happen.

All we have to do is lift progressively heavier weights and then rest for 24 – 48 hours before working that group of muscles again.

The Growth Time

So, how long will it take to grow your muscles? Well, that depends…

First of all, most people will not see any noticeable growth for several weeks, or even months. This is due to everyone’s differences in activating the nervous cells necessary for muscle growth. And it will take even longer for others to notice. That doesn’t mean nothing is happening. It is just a slow process.

muscle hypertrophy

Muscle hypertrophy depends on a lot of factors, the least of which is genetics. Some people can just grow muscle bigger easier than others due to their hormonal output, or the type and number of muscle fibers they have, or their ability to activate the cells necessary for growth.

Then there is age and gender. The older you are, the more time it will take to grow your muscles. And ladies, don’t fear. You will probably not become too “muscular” if you lift weights, only because you have lower amounts of testosterone, which is needed in greater amounts to grow larger and stronger muscles.

So, rapid muscle growth is probably not going to happen. It takes time. You will need to commit to the process and then follow the simple plan of progressively overloading your muscles during exercise, resting the appropriate length of time, and eating properly to ensure you have more protein available to synthesize than you broke down.


But My Muscles Get So Sore!sore muscles

Yes, your muscles may get sore. They don’t need to be sore to grow, but if you are progressively overloading your muscles, then they will probably be sore. They may start to get sore as soon as 6-8 hours after you work out, or it may not hit you until up to 72 hours after. This is known as Delayed Onset Muscle Soreness (DOMS), and it is a normal occurrence.

DOMS occurs when the muscle is damaged. This muscle damage occurs mostly in the connective tissue, so exercises that cause you to stretch a lot while lifting the weight will cause more DOMS. Keep in mind that you do not need to feel sore to for your muscles to grow. They will grow because of the tension and the metabolic stress mentioned above.doms

It is important to continue to give your muscles the proper amount of protein, even the day after you work out. Remember, this is when your body is repairing the muscles, and it needs protein to do this. It also needs all the essential amino acids, so be sure to read this article to understand how to get those as well.

Often the question is asked: Can I work out if my muscles are sore?

Yes you can, but it would be better to rest the sore muscles and work out a different group of muscles, allowing the sore muscles to repair and grow before exercising them again.

I like to work out each muscle group twice a week, with two days rest between workouts. Your recovery time may be more or less than mine. Listen to your body, and set your workout schedule accordingly.

Last Words

So there you have it.

Muscle hypertrophy is not that tricky. It is a three part process: exercise, rest, nutrition.bench press

Muscle hypertrophy is also not an overnight process. It will take time, but it will be worth the effort. It is a great feeling when someone notices all the hard work you have been doing. In fact, it happened to me today, and it felt great.

Thanks for listening.

As always, I am not a doctor or nutritionist; I am just offering my opinion based on my experience. Please consult a physician if you have concerns.

If you have any questions or comments, please leave them below.

Also, if you are a father (or mother) (or anyone for that matter) who would like an easy to follow program that includes a menu and work out information, check out this article from a few months ago.

See you in the next post.

Have a great day!


Tom Fitzsimmons

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