Female performing dumbbell bicep curls

If you look at different athletes from different training disciplines, you will notice the diversity of muscular development different people have.

This brings a question to mind – Are there different types of muscle growth and is more always better?

In this article, we’ll go over the two different types of muscle growth and explain which one you should focus on stimulating, depending on your goals.

The Two Types Of Muscle Growth

If you look at a muscle group, you will find that it is made out of separate muscle units, called myofibrils (muscle fibers).

These are the active, contractile components of your musculature, that make moving possible.

Around the myofibrils, there is a jelly-like fluid that contains non-contractile elements.

This is called the “sarcoplasm” and is used for energy during muscular activity.

There are two types of muscle growth we can look into:

  • Myofibrillar hypertrophy
  • Sarcoplasmic hypertrophy

Myofibrillar hypertrophy is the growth in the size of the separate muscle units, called myofibrils.

This type of growth is mostly sought after by strength athletes, like powerlifters and Olympic weightlifters.

The main adaptations that occur when myofibrillar hypertrophy is stimulated, are increases in relative strength and improved efficiency of the nervous system.

For this type of adaptation, bulk muscle growth is a secondary adaptation.

Sarcoplasmic hypertrophy, on the other hand, is the growth in the size of the jelly-like fluid around the muscle fibers, which we mentioned above.

This can be referred to as “bulk muscle growth” – something that bodybuilders and physique athletes seek.

The end results of this type of stimulation, are increases in bulk muscle growth, along with relative strength.

In this case, increases in maximum strength are a secondary adaptation.

Training tips

If you’re not a competitive athlete that needs to focus on developing physical properties, your best bet is to mix different types of stimulation.

Nevertheless, your training approach should be specific to your goals.

For instance, if your goal is to improve your maximum and relative strength, you should primarily focus on stimulating myofibrillar hypertrophy.

This is best done by training in the powerlifting rep range of 1-5 repetitions, but then again, you can do 6-15 rep sets every now and then to stimulate other adaptations.

If however, your goal is more oriented towards sculpting a bodybuilder-like physique, you should focus on the bodybuilding rep range of 6-15 repetitions.

Ultimately, you should try to combine low reps, high reps, slow reps, fast reps, etc.

To achieve the ultimate, functional, and healthy physique, you should incorporate all kinds of stimuli into your workouts.


What we see on the outside as muscles that make us look healthy, is actually a complex, adaptable system (the muscular system).

The two main types of growth that can occur in the muscular system are myofibrillar & sarcoplasmic hypertrophy.

The way you set up your training parameters and workout as a whole, will determine which type of growth will occur.

If you are looking for the best overall development, however, you should carefully mix your workouts and utilize different types of stimuli.