This article is the first in a series of articles that examine the efficacy of the famous Muscle-Tendon Change and Marrow Washing exercises on fascial fitness, bone and marrow health, and immunity. From a Chinese medicine perspective, these three elements are interwoven.
The Muscle-Tendon Change Classic (Yi Jin Jing) and the Marrow Washing Classic (Xi Sui Jing) are two methods of internal exercise attributed to Da Mo (Bodhidharma), a legendary Buddhist monk of the 5th or 6th century who is often credited with transmitting Buddhism to China. Purportedly Da Mo taught these exercises to monks of the Shaolin Monastery whose bodies were weak. The monks used Yi Jin Jing and Xi Sui Jing as methods of cultivating the body, mind and spirit to create a stronger, more flexible body that could then be used as vehicle for spiritual cultivation. Also according to legend, the practice of Yi Jin Jing and Xi Sui Jing led to the development of Shaolin Gung Fu. Some sources say that before the Song Dynasty (960-1279), Yi Jin Jing was only taught to Shaolin Temple monks, and only in the Ming (1368-1644) and Qing (1644-1911) dynasties did Yi Jin Jing become popular and branch out into several styles. 
Purportedly, Da Mo kept the two sets of writings in his meditation cave in the Shaolin Temple – the Muscle-Tendon Changing Classic, a method for changing and renewing tendons and sinews, and the Marrow Washing Classic (Xǐ Suǐ Jīng 洗髓經), a method for cleansing and washing the marrow (thereby renewing the body’s Essence (Jing). During a renovation to a cave wall at the Shaolin Temple, the two scriptures were discovered and become known to the public. There is some disagreement on whether these two practices are in fact the same practice, two connected practices, or two entirely separate practices.
The earliest mention of the Yi Jin Jing is attributed to Zhang Jun Fang in the Song Dynasty, while the earliest account of the modern 12-movement exercises is included in the Illustrations of Internal Exercise compiled by Pan Wei in 1858 in the Qing Dynasty. To further complicate matters, there is a version of Yi Jin Jing taught in Taiwan that contains 18 movements rather than 12. In addition, various versions of the Yi Jin Jing have been passed down by Daoist sects, who see the Yi Jin Jing as a method self-cultivation and transcendence, and martial arts groups, who employ the Yi Jin Jing to strengthen the body and develop power.
Many scholars feel that the Marrow Cleansing Classic and the Muscle-Tendon Changing Classic were edited by Zining, a Ming Dynasty Daoist priest. However, some Buddhist sources feel that these methods come from Buddhism and are part of Chan Buddhist practices (Zen). Because of the interweaving of Daoism and Buddhism at different periods in Chinese history, it is difficult to trace the source of these methods as they come down to us today.
The Yi Jin Jing has also been adopted as a medical Qi Gong practice, and its movements analyzed from the perspective of Traditional Chinese Medicine.
The Muscle Tendon Change & Marrow Washing
The Muscle-Tendon Change promotes transformation of the sinews (Jin). Martial arts practitioners feel that the Muscle-Tendon Change develops “tendon strength” rather than muscular strength. The Chinese word Jin 筋, refers to not just tendons, but to the sinews – tendons, muscle, ligaments, fibers or fibrous tissue, or protruding venous structures. The term “sinews” in this context, includes the fascia.
One of the things traditional martial artists are referring to when they talk about “Tendon Strength” or “Sinew Strength” is the recruitment of long chains of muscles, tendons, ligaments and joints to generate whole-body power. This can manifest as a resistance force, elastic force, and the emission of force over a short distance. Rather than relying on segmented movements that increase momentum to generate power, the goal is to try to initiate force from the whole body moving as a unit. Therefore, rather than strengthening individual muscles, training focuses on “whole-body” “unified” power, in which the body moves as a single unit, gathering and releasing power simultaneously. This is achieved by increasing the strength and connectivity of the Jin – the sinews. When the sinews are correctly trained, the result is an elastic, power dynamic. Therefore, in the context of the martial arts, an important aspect of the Muscle-Tendon Change is its function as a foundational exercise for learning to emit (send out) Qi.
While the Muscle Tendon Change focuses on Qi, Marrow Washing focuses on Jing and blood (Xue). The Muscle-Tendon Change focuses on the membranes and spaces within and between the fascia, and Marrow Washing focuses on the marrow inside the bones and the circulation in the membranes around the bones. Creating a reservoir of Qi in the various layers of the fascia, and particularly in the layer between the bones and the sinews/muscles, helps to lead Qi to enter the bones and stimulate the production of blood and marrow. In Marrow Washing, Qi is guided into the bones longitudinally through the joints, and into the bones via the small channels (“network vessels”) that wrap the bone. This combination strengthens the bones and stimulates the bone marrow, thereby increasing the production of Jing and blood, while nourishing the tissues and improving circulation to every part of the body.
My recent experience with these exercises is an ongoing training in response to a series of shoulder injuries occurring over many years that resulted in my shoulder “suddenly” becoming weak and unstable. I could feel the joint separating and slipping in and and out of alignment even in simple everyday movements. In the past, practicing internal martial arts had always solved musculoskeletal issues. This time, while martial arts exercises helped to a degree, they were not strengthening the tissues specifically enough to really rehabilitate the shoulder.
In desperation I went to friend of mine, a fellow practitioner of Chinese Medicine, who suggested I take collagen supplements in conjunction with vitamin C and isometric exercises (holding a plank position). The exercise was timed to be five minutes of intensive exercise performed 30-40 minutes after taking collagen and Vitamin C, which had to do with the timing of the uptake of collagen into the body.
This protocol did at first create some stability. I was able to lift things without pain and even do outdoor work like raking leaves, but it did not increase stability significantly in the various angles the shoulder must operate in martial movements and applications, and there were still everyday actions where the shoulder felt weak and unstable. As I should have realized from studying exercise physiology decades ago, isometrics only strengthen muscles in the angle or angles in which one performs the isometric exercise. This makes them great for the initial stage of rehab when mobility is limited, but less useful in later stages when a joint must be stable throughout the range of motion and the muscles must have strength throughout their contractile range and in different planes of action.
Finally I went back to the source, relearning the Muscle-Tendon Change exercises I had learned many years ago and practicing them every day in conjunction with Marrow Washing Nei Gong. During the first two months of practice, I began to realize the importance of performing both sets of exercises correctly in accordance with the traditional method of practice, which is internal, rather than a set of externally focused exercises. This is difficult, as every movement and posture must be imbued with focused Mind-Intention and correct use of the breath. After several months I began to understand that when practiced correctly, the Muscle-Tendon Change and Marrow Washing Nei Gong meet every requirement for correct training of the fascia and transforming fascia, as well as restoring damaged or aging fascia to a healthy and vibrant state.
Within 10 weeks of daily training my shoulder became much more stable on every plane of action. After 14 weeks (the time of this writing), I can easily do 10 repetitions of Lying Tiger Pounces on its prey, which contains a “Hindu-style” pushup (I could not do one without pain previously). I can also execute martial arts strikes with power, can lift heavy things and split logs with an axe without pain or slippage in the joint.
After 14 weeks of training the Muscle–Tendon Change exercises, I added the Rubbing-Patting (An Mo/Pai Da) part of the Muscle-Tendon Change, which leads Qi into the fascia where it is stored and can circulate freely. This aspect of the Muscle-Tendon Change is said to “pack,” “fill up” and thicken the fascia. The results are interesting. At first it seemed like nothing was happening, but with daily practice I could feel the areas of the body I was patting and rubbing begin to fill up, and over time the sensation of filling these areas lasted longer and longer. By the time I reached the stage of patting and filling the Du Channel and the arms and legs (which begins in the eight month of practice) these sensations became strong, with a sense of increased vigor throughout the entire body. Very quickly I could feel the whole Ren Channel fill, and the Du Channel become activated, and my digestion and energy levels improved.In the 8th to the 11th months one gently strikes the chest with a hollow fist and then rubs the lower abdomen (already activated and filled in previous months). At this point I could feel Qi filling up the body and my entire body felt energized and vibrant.
Although I learned the Muscle-Tendon Change and Marrow Washing Nei Gong many years ago, I practiced them for a short period of time and then went on to practice more direct martial exercises and training methods. In looking back, I can see that I did not practice Muscle-Tendon Change correctly nor did I train the Muscle-Tendon Change Exercises and Marrow Washing the requisite amount of time to actually transform the fascial tissues and marrow.
In the following segments of this series of articles, we will look at fascial training as it is understood and expressed today, and its relationship to the Muscle-Tendon Change and Marrow Washing Nei Gong. This will involve examining “fascial science,” and current understandings of the function of the bone marrow in relation to the other structures of the body. We will also examine the effects of aging and modern lifestyle on the fascia and bone marrow, and exactly how the Muscle-Tendon Change and Marrow Washing Nei Gong restore tissue health.
 Chinese Medical Qi Gong, Liu Tianjun, (Philadelphia and London: Singing Dragon 2010), p. 248-249.
 “Yi Jin Jing” The Classics of Changing Tendons: 中国武功经典：易筋经 (100 Books of Ancient China Classics Book 23). China Kungfu and Yi Jin Jing. Compiled by the Chinese Health Qi Gong Association (Beijing: Foreign Language Press, 2007) p.3.
 Yi Jin Jing. Compiled by the Chinese Health Qi Gong Association (Beijing: Foreign Language Press, 2007) p.3.