Myofibrillar vs. Sarcoplasmic Hypertrophy: Think Small to Get Big!

muscle fiber anatomy: myofibril, sarcoplasm

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Think Small to Get Big!

When you think of getting bigger muscles, you tend to think of just the outer appearance of the flesh covered muscle increasing in size until it makes that impressive massive bicep. However, just as scientists needed to study matter down to its sub-atomic structure to create the incredible power of the hydrogen bomb, athletes wanting to increase muscle size and strength can benefit by studying their anatomical structure down to the cellular level.

For example, if you were to look at a slice of muscle tissue through a microscope, you would see that there are many different components comprising its total mass, and each of these components offers us an opportunity for new growth!

Muscle fibers actually only represent about 85% of total muscle mass. The remaining 15% of muscle mass is made up of non-contractile components such as sarcoplasm (fluid that contains the material within the muscle cell), mitochondria (energy production), glycogen (fuel), capillaries (delivery of oxygen and nutrients), fat cells, and connective tissues. Think about that for a minute. That means there is a 15% growth potential in learning how to increase the components within the muscle cells themselves!

These growth opportunities will fall under two main categories—myofibrillar hypertrophy and sarcoplasmic hypertrophy.

Myofibrillar Hypertrophy vs. Sarcoplasmic Hypertrophy

myofibrillar vs sarcoplasmic hypertrophyWithout getting too deep into anatomical terminology and processes, we will now look at a simple explanation and example of each of these categories of growth. Keep in mind though, that the more time and effort you are willing to put in to researching and increasing your knowledge of the human body, the more you will understand how the body functions and what you can do to attain its optimal performance.

That being said, myofibrillar hypertrophy refers to the growth of the actual muscle fibers, and sarcoplasmic hypertrophy refers to the increase of fluid and all non-contractile components of the muscle. A good analogy would be a water balloon. Myofibrillar hypertrophy would be like increasing the thickness of the balloon material, and sarcoplasmic hypertrophy would be like adding more water.

Myofibrillar hypertrophy imparts more strength and speed due to the increased force potential of larger muscle fibers. And though sarcoplasmic hypertrophy does increase muscle volume, the increase comes from added supportive components that provide more endurance than functional strength and speed.

Therefore, an argument is made that myofibrillar hypertrophy is more beneficial for athletes requiring explosive strength, like power lifters and sprinters, and sarcoplasmic hypertrophy would be more useful to bodybuilders who rely more on maximum muscle size than function. While this argument does make sense, it does not mean that both groups could not benefit from both types of growth.

How to Specify Training for Each Type of Growth:

heavy weights less repsMyofibrillar Hypertrophy – Training for myofibrillar growth usually involves very heavy weights with low reps (1-6) at a fast tempo, longer rest periods between sets (3+ minutes), and less volume.

light weight less repsSarcoplasmic Hypertrophy – Sarcoplasmic hypertrophy training requires moderate weights with higher reps (8+), shorter rest periods (under 3 minutes) and more volume. Supplementing with creatine and staying well hydrated throughout the day can also aid in increasing sarcoplasmic hypertrophy.

Visualize and Meditate

man meditatingNow that you know the differences between myofibrillar and sarcoplasmic hypertrophy, and how to train for each, let’s go further, and think even smaller, to get even bigger!

What is even smaller than the myofibrils and capillaries within the muscle?

importantce of nutritionHow about the micronutrients that are carried in your blood through the capillaries and the chemical transmitters carried across nerves to nourish and activate each muscle cell respectively.

Muscle is completely useless unless it can contract in a controlled manner. Without proper nutrition, providing the vitamins, minerals and enzymes needed to orchestrate the fine-tuned muscle contractions, you will not reach your optimal potential.

By educating yourself as much as you can about your body and nutrition you will be able to visualize and meditate on what is happening down to a molecular level. Visualizing and meditating on these processes happening in your body throughout the day, and as you train, will not only remind you of the importance of proper nutrition, but will also reinforce a level of awareness that can translate into actual gain.

Visualization and the Impact on Performance:

Richardson (1969) basketball studyMany studies have shown the real effects of visualization on performance. One such study, Richardson (1969), showed an amazing improvement in basketball free throw skill. Richardson had one group practice free throws every day for twenty days. Another group practiced free throws only on the first and twentieth days with no practice in between. And a third group, practiced only on the first and twentieth day as well, but they were also instructed to visualize sinking baskets for twenty minutes each day.

As you can probably guess, the first group, that actually practiced, improved by 24 percent, and the group that did not practice did not improve at all. But what is truly remarkable, and shows the power of visualization, is that the third group improved by 23 percent!

This means that the effect on performance from actually practicing and the effects of visualizing practice were almost the same! Numerous other studies have found similar effects, and the general consensus is that the same motor neurons used in the actual physical performance are also stimulated with mental imagery. Furthermore, the more detailed one can create an image, the stronger its effect.

In the basketball example this would mean imagining the feel and the weight of the ball, the sound of it bouncing, and the sound it makes as it leaves your hands and then travels through the net.

The Bottom Line

human body systemsAfter reading this article, you should walk away with an awakening of your awareness to what is actually going on under the skin and in the muscle itself at a microscopic level.

Now, each time that you lift a weight, perform an exercise, or eat a meal you will consider what is happening not just to what you see in the mirror, but below the surface to your very cellular makeup.

Your muscles aren’t just magically growing; there are specific processes that you can help to ensure function at their optimum, and guide them to achieve your goals by educating yourself how to eat, train and visualize for success.


1. Richardson, Alan W. (1969). Mental Imagery. Routledge.

Author Profile: Dax Tucker

Dax Tucker has over 29 years of weight training experience, a black belt in Tae Kwon Do, and is a tournament chess player and yoga practitioner. He also has an MBA, and a BA in psychology. In June of 2011 he released his first published work, "The Leaf Catcher," that is bound to be a modern classic. "The Leaf Catcher" is written in the style of Dante's Divine Comedy and explores and defines the human mind, body, and soul. Dax is currently married with 3 children, and lives in the Pacific Northwest.

Disclaimer: The views of the author are his or her own, and do not necessarily reflect the opinions of Ask The Trainer.

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