The fascial studies cited within this series of articles are quite fascinating and informative, however they raise as many questions as they answer, particularly vis-a-vis internal martial arts training.
In the internal martial arts, true strength and power are said to come from softness, and true movement from stillness. The Great Xing Yi boxer Liu Qi Lan said:
The function of the Daoist arts is to empty the mind within. When there is no effort, there is centering. When there is no expectation, there is obtaining. Follow the easy balanced way and the moment will emerge. [It says in the Boxing Classics:] “The boxing is without boxing. The intention is without intention. Within no intention is true intention.” Stillness is the fundamental form. In movement lies the function.” By being silent and still, then upon sensing anything, you connect with it, and everything you do will be right. 
The Nei Gong Zhen Chuan says:
The critical factor between success and failure lies in the intervals between the firm (Gang) and the yielding (Rou); movement (Dong) and stillness (Jing),  for without great care in this one can be caught off-guard! It is imperative that when moving the stance-steps the heart remains unmoved, when moving the body the Qi remains unmoved. Then the heart will be calm and the stance-steps solid, the Qi can be calm and the body stable. Then the Jingshen can soar and change and transform. Therefore, once stillness is understood as stillness; [then] motion is also stillness. Once motion is understood, as motion, [then] stillness is also motion. Stillness is used in motion, not motion in stillness. In the transported spirit, the spirit is slow and the vision is fast, and the heart is slow and the hand is fast, and Qi is slow and the step is fast. Generally, it is necessary to be fast externally and to be slow internally, and to be gentle (yielding) internally and to be firm externally. This is the mystery in theory and practice. Firmness that comes from yielding, is true firmness. Speed that comes from slowness is true speed. Its mystery can not be understood through the external form. 
The idea of yielding (supple) and firm is also understood through exploring the concept of Song Jin. Song (松) can refer to a pine tree, but it also means to loosen or slacken, let go, or relax. The Nei Gong Zhen Chuan says: Jin must loose (Song) yet taut. At first the Jin must be slack, which can be followed by tightness. Only with slackness as the pivot can tightness reach its fullness. Therefore, the slack gives rise to the taut, the taut cannot become slack.  Song implies slack yet resilient, like a slackened rope that can tighten again, or hair that was bound up that has been let down. In Chinese martial arts a favorite example of Song is a pine tree with snow on its branches. The branches hang under the weight of the snow but retain an inner resilience. When the snow falls or is brushed off the branches spring back. A more modern take on this is that:
The slow-motion and deliberative Fang Song (Relaxing Loosening) methodology works to rein in the dominant muscle actions, and allows the inner muscles to fire more so that the internal and axial movements can better align and balance in the actions. This induces more optimal muscle activations at higher levels, which leads to more coherent bioenergy. The higher activation levels of the muscles are often experienced as a surge of heat in practice, registered as qi. The body learns to associate the elevated qi energy as a biomarker of better balance and alignment of muscle actions. This association in time grows the Qi as a more defining marker to regulate motion of inner balance. 
Statements like these lead to many questions:
1. How does Song Jin play a role in fascial training?
2. What about other types of Jin that are trained in internal martial arts – how do they relate to fascial training?
- Visible Jin (明劲 Ming Jin): First firm and afterward yielding.
- Hidden Jin (暗劲 An Jin): First it yields and then it is firm.
- Elastic Jin (弹劲 DanJin): Jin accumulates and gathers like holding down (coiling) a spring. Borrowing power and releasing Jin is like a slingshot.
- Shaking Jin (抖劲 Dou Jin): Dou Jin occurs in an instant, like a horse shaking off a fly.
- Extending Jin (挣劲 Zheng Jin): Zheng Jin stretches left and right, moving outward in opposite directions. Zheng Jin is firm and quick.
- Drilling Jin (钻 劲Zuan Jin): Spiral rotation is drilling. It is like twisting silk around a nail. Zuan Jin is yielding at the start and then becomes firm.
- Rotating Jin (旋劲 Xuan Jin): Circular, elastic and spiraling. Xuan Jin is quick, firm and steady, like a revolving wheel.
- Transforming Jin (化劲 Hua Jin): Hua Jin is like a ball floating in the air. Outside Hua Jin is yielding and restrained, receiving power by rotating. Inside, it contains spiraling and turning. Hua Jin yields, sticks, sinks and is firm
- Wrapping Jin (裹劲 Guo Jin): Winding like a snake, Jin enters the center. The eight directions unite and concentrate. Guo Jin is heavy (sinking) and stable. 
3. How does mind-intention and the cultivation of intention-no-intention (Yi Bu Yi) affect the fascial system and its ability to perceive and respond to stimuli?
4. Vis-a-vis the fascial system, why is Zhan Zhuang (standing) considered the paramount training in arts like Xing Yi Quan? What is the effect of standing on the fascial system and the development of strength and power?
5. Does the inner sensing cultivated in Zhan Zhuang create subtle and profound changes in the fascial network?
6. If bouncing elastic movements train the fascia, how does moving incredibly slowly, as in exercises like Tu Na Si Ba, or the slow practice of Tai Qi Quan, develop speed and elastic power?
7. In the internal arts, we often say there are three kinds of breathing – normal Dantian breathing (deep abdominal breathing), Reverse breathing and “Fetal” (“Pore” or “Whole Body”) breathing. How do different kinds of respiration affect the fascial system and stretching?
8. Do different breathing methods create different tensions in the fascial system by changing the intra-abdominal pressure? Do these methods of breathing create pressure changes and tensile changes within the Upper and Middle Dantian (thorax and cranium)?
9. The Piezo-electric and Bio-magnetic phenomena in fascia and the body have yet to be fully explored. Studies in Japan have showed that practitioners of health, martial arts practitioners, Qi Gong practitioners etc. were able to emit strong electromagnetic fields from their hands (1,000 times stronger that the normal human biomagnetic fields). These fields were measurable with a simple coil magnetometer. What is the role of bio-magnetic fields in fascial training and the internal martial arts?
10. Brain activity of “healers” from a variety of subcultures was studied by Robert Beck. Using an EEG, Beck noticed that they all had similar brain wave patterns when in “their altered state.” Beck also found that the brain waves phase and frequency synchronized to the electric field of the earth.  Researcher James Oscherman connects many of these studies with the following statement: We can speculate that these practices have in common and alteration of the connective tissue/cytoskeleton or tissue-tensegrity matrix system that enables individuals to synchronize or entrain their biomagnetic fields with their brain waves and the Schumann resonance in the Earth’s atmosphere. The result may be a whole-body collective oscillation, possibly driven by the higher frequency Frohlich oscillations involving virtually all of the billions of collagen molecules in the body, and, possibly, the water molecules associated with this quasi-crystalline array.  This research leads to whole host of questions!!
11. What is the role of water and fluids in tendon strength and fascial training? Recent studies have indicated that liquid crystalline aligned with collagen fibers in fascia may act like a super-conductor. Ho Mae-Wan has suggested that water confined in the small nanotubes within the fascia, being far more ordered, could be superconducting, because jump conduction could occur simultaneously down multiple chains of hydrogen-bonded water molecules. Superconductors are also able to maintain a current with no applied voltage whatsoever. Experiments have demonstrated that currents in superconducting coils can persist for years without any measurable degradation. Later, Gary Fullerton and colleagues at Texas University offered a convincing model of liquid crystalline nanotubes of water interwoven with the triple-helix molecules of collagen molecules in the collagen fibers. 
In closing, it is useful to return to the Nei Jia concept of power, strength and the inter-connectedness of the human body. What is often forgotten in scientific studies and models is the importance of mind and spirit in cultivating strength and power (Jin-Li).
Zhao Da Yuan, a master of Ba Gua Zhang and Qin Na, lists 6 Necessities (6 Musts) for gathering and releasing power:
- Shen is concentrated; Heart-Mind is calm.
- Gather Qi, loosen and sink.
- Firmly embrace Dantian.
- Use Intention (Yi) to lead Qi, and use Qi to urge.
- Each section urges the other, in order to release from the tips.
- Zheng Jin (Whole Jin) is integrated.
Master Zhao goes on to detail the three-step training method for developing power and fascial strength:
- Zhan Zhuang: Quietly holding a posture for a period of time in order to experience the body as an integrated organic entity. When one is still, the whole body is still. When one moves, the whole body moves. At the same time, Jing Shen is conserved internally and Qi is guided by the intention so that Dantian can gather and release.
- Coiling and Releasing: This means to train and test structure (posture), and refers to practicing the forms and movements with intention and spirit, and training the body to release whole body force (Fa Li). Qi and blood must circulate smoothly. One must employ Intention, and not use forced power, which leads to clumsy strength. This requires employing the understanding of Jin Li developed in Zhan Zhuang training.
- Drills and Application Oriented Exercises with a Partner: Developing the ability to change according to the changing situation, so that the Jin-Li is continuous, circular and alive.
Lastly, Master Zhao tells us that Jin-Li must have five important qualities:
- Zheng (Whole, Integrated): The various forces distributed throughout the body must integrate and consolidate into one. This is likened to the Earth Element.
- Tou (Penetrating): Having the intention of piercing through – Intention, Qi, vision and Jin Li must all “pierce through.” This is likened to the Metal Element.
- Yuan (Round): Every part of the body is round and curved. The body spirals, rotates and rolls, like a floating ball. This is likened to the Fire – like a Wind stirred by Fire.
- Huo (Lively): The body is loose and unblocked. The Qi is like floating clouds and the internal Qi and Jin, flow and change according to the situation. This is likened to Water adapting its shape to the form.
- Qiao (Clever, Skillful): Skillfully changing and transforming. One thing generates ten thousand things, all of which connect and respond to each other. This is likened to Wood, generating ten thousand branches and leaves. 
To read all 6 parts of the this article in Spanish go to: Budo Blog
拳意述真Authentic Explanations of Martila Arts Concept. Sun Fu Quan [Su Lu Tang]. March, 1924. Translation by Paul Brennan: https://brennantranslation.wordpress.com/2013/04/29/the-voices-of-sun-lutangs-teachers
 Gang刚; Rou柔; Dong动; Jing 静
 Nei Gong: The Authentic Classic – A Translation of the Nei Gong Zhen Chuan, Tom Bisio, Huang Guo Qi and Joashua Paynter (trans). (Denver: Outskirts Press, 2011) p. 75.
 Ibid, p. 9.
 “A Scientific Perspective of Neijin (Internal Strength)” C.P. Ong* (International Journal of Complimentary and Alternative Medicine, Volume 5 Issue 3 – 2017) https://medcraveonline.com/IJCAM/IJCAM-05-00155.php
 Practical Qin Na Part 2:Foundational Training, Techniques and Methods. Zhao Da Yuan, translated by Huang Guo Qi and Tom Bisio (Outskirts Press Inc, 2016) p.27-29.
 “Detection of Extraordinary Large Bio-Magnetic Field Strength from the Human Hand” A.C. Seto, S. Kusaka, et als. (Acupuncture and Electro-Therapeutics Research International Journal 1992) 17: 75-94.
 “Mood Modification with ELF Magnetic Fields: A preliminary Exploration” Archaeus 4:48 and A Biophysical Basis for Acupuncture. James Oschman Ph.D (Dover NH: Nature’s Own Research Association, 1993) p. 49-50
 A Biophysical Basis for Acupuncture. James Oschman Ph.D (Dover NH: Nature’s Own Research Association, 1993) p. 50.
 “Super-Conducting Liquid Crystalline Water Aligned with Collagen Fibres in the Fascia as Acupuncture Meridians of Traditional Chinese Medicine” Ho Mae-Wan. Forum on Imuunopathological Diseases and Therapeutics – January 2012. https://www.researchgate.net/publication/255996190
 Practical Qin Na Part 1: Explanation of the Qin Na Nine Heaven Secret Text. Zhao Da Yuan, translated by Huang Guo Qi and Tom Bisio (Outskirts Press Inc, 2015) p. 270-277.