Social Icons

Friday, June 28, 2013

The Science Behind Muscle Growth (Part 1)

For most of us, weight training seems to be a fairly simple practice because we all know that we have to lift weights and rest for a while and then lift more weights.  As you progress you will improve over time and your muscles will develop by increasing in size and strength.  But in reality, sometimes things don’t go according to plan as the above theory might imply.

The Relationship between Strength and Size

A lot of bodybuilders run with the notion that increases in strength are not always related to increases in muscle mass.  You must have heard of the saying that bodybuilders aren’t as strong as power lifters.  I am afraid that this is a misconception. 

How about this theory....strong people tend to have better body mechanics than weaker people. By this I mean better joint lengths and connective tissue factors (such as attachment placing and finer tendon and ligament strength).  Naturally strong people possess more type II fibers and a more effective nervous system (which can be manipulated).  Muscles can be trained to become stronger but they cannot be trained to get bigger.  Trainings factors such as rep range and frequency of training sessions play a part. If a muscle gets stronger, then naturally within a rep range which is conducive to producing muscle growth, then the muscle will grow in size.

Scientist have proven time and time again that muscle mass and muscle strength are directly linked.  In order to understand further the point I am making, it is important to look at what happens to your muscles when you train them. Here is a snippet from "The Neuromuscular Series”:

“Muscle biopsies of experienced bodybuilders have shown that it was the size of the individual fibers within their muscles that was responsible for the abnormal muscle size and not the actual number of fibers present.” Although there is some evidence that extreme conditions may result in modest increases in fiber number (hyperplasia), the mechanism responsible for muscle size growth is hypertrophy – the increase in size of existing muscle fibers.

Here Is another Snippet From The “Neuromuscular Series”:

“It is also worthy of note that contractile machinery comprises about 80% of muscle fiber volume. The rest of the volume is accounted for by tissue that supplies energy to the muscle or is involved with the neural drive.”

To summarize the above, it tells us that there are two ways to increase muscle mass:

•         The first is to increase the volume of the tissue which supplies energy particles to the muscle that is being trained -  sarcoplasmic hypertrophy
•       The second is to increase the volume of contractile machinery – sarcomere hypertrophy

Let us analyze the above in more depth:

What is Sarcoplasmic Hypertrophy?

Sarcoplasmic hypertrophy is concerned with increasing the volume of tissue that is responsible for supplying energy levels to the muscle that is being trained. Intercellular bodies that are also known as mitochondria are intrinsically involved in the production of ATP.  Muscles contain fibers that adapt to high volumes of reps that form part of a training regimen by increasing the amount of mitochondria in the bloods cells.

They will also contribute to increasing the volume of enzymes involved in the oxidative phosphorylation and anaerobic glycolysis mechanisms that aid the production of energy and also increase the volume of sarcoplasmic fluid that sits inside the cells as well as the fluid that sits in between cells.  This type of hypertrophy has little effect on any added muscle strength and it is mainly concerned with aiding increased endurance (your ability to do reps at a certain weight) and increasing the muscle’s ability to produce ATP.

The Hypertrophy Factor

Sarcoplasmic hypertrophy plays a direct role towards moderate increases in muscle size.  ATP is also the source of energy attributed to muscular contraction including type II fibers. This begs the question: wouldn’t an increase in sarcoplasmic hypertrophy within the muscles which would allow a greater ability to produce intramuscular quantities at any given time, be an asset?  The answer is obviously yes. 

This highlights the importance of sarcoplasmic hypertrophy in bodybuilding. As far as increasing the tissue involved with the neutral drive is concerned, this would, in theory occur in direct response for the need of contracting cells through hypertrophied contractile machinery.  In isolation, this would provide a very little contribution towards added muscle size. Additionally, there are other intracellular bodies whose growth and development would fall into the category of sarcoplasmic hypertrophy.  These would include organelles such as ribosomes which are concerned with protein synthesis. They have little direct impact on muscle size but they do support sarcomere hypertrophy which we will cover in Part 2 of the article.

About The Author

James McDuffy works for The Muscle Growth Expert. You can visit his website for more info on different aspects of bodybuilding and the science behind muscle growth.  Alternatively you can follow him on Twitter.  

Published by