SCIENCE OF YIN YOGA 63why they are able to. Bolstered with tensioned fascia, people can tap into
extraordinary levels of strength.
A fibroblast is a type of cell that builds collagen and is the most common
type of cell in the connective tissue of animals. The primary function of fibro-
blasts is to maintain the structural integrity of connective tissues by secreting
materials that create the extracellular matrix. In addition to providing key
structural support, they also play a pivotal role when tissue has been injured.
They act as an emergency responder, alerting the immune system to invading
microorganisms and setting the stage for recovery to begin.
The collagen and certain proteins in the extracellular matrix make the
fascia stronger and thicker. Collagen is often referred to as a “complex pro-
tein” because it contains 19 amino acids. Glycine is one particular amino acid
found in collagen that produces muscle growth. Although this produces more
strength within the body, it can come at a price. In some circumstances, the
body begins to lose its suppleness, and wherever the buildup of extra collagen
has taken place, range of motion suffers. A classic example of this is profes-
sional bodybuilders. Although they have massive muscles, they are unable
to move the body in all the ways it is capable of moving. For bodybuilders
simple tasks such as taking off their shirts, tying shoes, or scratching their
backs become nearly impossible. In this case, strength has actually become
a hindrance (Clark 2012).
What’s the point of having strength if you can’t use it? The good news
is that the extracellular matrix can restore flexibility when the contractions
relax. By relaxing the fascial system, a remodeling of sorts takes place. The
extra material that was created through the sustained contraction is eaten up
by macrophages within the extracellular matrix. Macrophages are a type of
white blood cell that eat up cellular debris, foreign substances and cancer
cells; they are like the janitors of the cellular world. The components of the
fascial material will then produce more elastin and restore the tissues’ flexi-
bility (Clark 2012).
Subserous Fascia Although yin yoga doesn’t directly affect this third clas-
sification of fascia, I want to discuss it so that you are informed. Think of this
as a little extra credit. The subserous fascia, sometimes called the visceral
fascia, supports and suspends the organs within their respective cavities (see
figure 4.9). Each organ is wrapped in dual layers of fascia that are separated
by a thin serous membrane. If these connective tissues are too loose (yin),
then it causes organ prolapse (displacement of an organ), and if they are too
tense (yang), it restricts optimal organ function. Even on this very deep level
of the body, we see the importance of balancing yin and yang.