65phase change, where you begin to access the deep fascia and connective tissues, such
as tendons, ligaments, joint capsule, and even the bone. This is when you start to reap
the benefits of the good stress. By pressurizing the exposed tissues, you create a positive
stress effect. At this point, the fibroblasts go to work. As you stress the fibers within the
fascia, the fibroblasts secrete chemicals that rearrange the collagen, making the tissues
stronger. The fibroblasts provide a similar function within the rearrangement of the elastin
fibers, making the fascia more supple. This process has a positive effect on the tendons
and ligaments because you are stressing them in a yin manner too.
In this sleeping swan example, the key structures that benefit are the hip and iliotibial
band. This fibrous band runs along the outer thigh and is said to be so strong that it can
support the weight of a car. How they figured that out, though, I don’t know! Because
of the spinal flexion, sleeping swan also stretches the ligaments in the lumbar spine.
Typically, the ligaments in the lower back are the most flexible in the body. As you get
older, though, the elastin fibers become mineralized, cross-linked with other fibers, and
therefore more restricted. However, holding this type of deep stretch keeps the elastin
fibers cleanly organized, and the ligaments remain healthy.
In addition to positive effects on connective tissue, yin yoga benefits the bones as well.
Earlier we learned that the outer covering of the bone, the periosteum, is made of fibrous
connective tissue. If the periosteum is unhealthy, bones will snap like a dry tree branch
under pressure. However, exerting positive pressure on the bones stimulates the body's
fibroblasts to increase the collagen of the periosteum. As more collagen is created, the
periosteum adapts to the pressure by becoming more durable and resilient, like a living
tree. Over time, it's as if you are exerting pressure on the branch of a living tree instead of
a dry, dead tree branch. Because a living tree is hydrated and flexible, this elastic nature
makes its branches much more difficult to break.
This is why when you practice, you often feel it in your bones. You actually move that
deep into the body when you practice yin yoga. The entire fascial matrix is pressurized
and benefits. After three to five minutes, you slowly exit the sleeping swan. Commonly,
you feel tenderness within the stretched areas because it takes a long time for the con-
nective tissues to open and also takes a long time for them to revert to their original
positions. That dull, achy sensation you feel is a good sign. Because the connective
tissues are connected into a vast network, the benefits of your yin practice will benefit
every movement that you do. You’ll most likely notice that it improves your sleep quality
too by releasing unnecessary tension.
FIGURE 4.8 Sleeping swan pose.