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Internal v external


People always think of strength as the need for bigger muscles.  Putting on more muscle will make you stronger to a certain extent, but those bigger stronger muscles will still pull against poor quality connective tissue.


Force is propagated from the internal tissues out to the external muscles.  Internal tissue quality is a weakness that is seldom thought of.

There are two ways of getting strong.

1. By improving the quality of the muscle contraction


2. By improving the quality of the connective tissue,                 making it more responsive to the pulling of the muscle.

If muscle is pulling into connective tissue that is less responsive because it is less stiff you are going to bleed energy through the connective tissue.  High muscular output but poor quality connective tissue leads to energy leaks through the connective tissue and eventual injury.  

In addition, the athlete will hit upper barriers of how much strength you can generate with your muscle tissue if you're pulling against poor quality connective tissue.  

If you pull on stiffer connective tissue you get more force output and a system that is much more resilient against injury.

Develop your internal strength

Body ecology

The external environment essentially reproduces a goal, like an exercise or movement pattern.  These "named" exercises, like bench press or squat that we still use today, were actually developed at a time when we knew very little about muscle physiology.  The goal is the external display of repeating a movement while the internal tissues are ignored.

The internal environment is the available space in the joint and the surrounding connective tissues.  This is the primary output measure the body uses to regulate musculoskeletal output. 

A change in perspective

Traditionally, training to enhance performance has prioritized external goals as the main determinant of success.  Displays of strength, speed and agility have been emphasized at the expense of the internal system. 


Simple exercise selection is not the main driver in strength and movement enhancement.


Therefore taking this internal, human-centered approach, instead of a random selection of exercise approach, quickly changes the goals of training from external strength displays to cultivating a stronger and more robust internal system.

"In skeletal muscle, interactions between contractile and connective tissue elements at multiple scales results in emergent properties that determine mechanical performance."

Eng et al, 2018

If you only train the result, the exercise or patterned movement to the exclusion of the internal tissues where movements are created, you will experience rapid internal deterioration and development in compensation leading to deficits in performance and injury.

You must cultivate and maintain a robust internal system in order to support the production of external patterns.


The brain sees and creates movement from the inside out.  The organization of our training should reflect this.  With these concepts in mind, we can refocus training goals to build specific tissues, suited to specific tasks, that can meet the challenges and variability of human performance.

Strength and movement are emergent, biologial phenomenons that follow four simple truths:

*All movements are created internally

*All movements are executed internally

*Internal constraints are always the first to overcome

*External displays of movement are an expression of internal function

Dr. Andreo  Spina

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