Numerous studies have been made in the field of budo studies concerning the “Body and Mind Theory”. These previous studies point out that the influence religion has in the Body and Mind Theory of early-modern period budo was actually Zen Buddhism’s “Doctrine of Self Discipline”.

This paper, utilizing prior research conducted by this author on the ideology of the sword, reveals another side to the history of budo previously unexplored in the aforementioned studies. This research will also delve into the significance, background, and circumstantial formation of the concept of budo throughout the principle countries of the Far East, namely Japan, China, and Korea.

The results are as follows:

・The concept of “Divine Gifts”, or divinely-granted power, can be seen in the process of acquiring secret teachings from the most distinguished swordsmen in the Muromachi period of the Middle Age, and yields a thread of commonality, as stated below:

1) Ascetic prayer at Shinto shrines

2) Penance as a prerequisite

3) Acquiring divine gifts through dreams

・The techniques of acquiring divine gifts or power find their place in the Shinto world where magic can eliminate evil. These techniques affect both the external and internal side of a twofold reality, where the killing of an actual enemy is correlated to eliminating the evil present in one’s own mind.

・Regarding magic in swordsmanship, the connection between the sword and the divine is important, and this connection was authorized by mythical imagery.

・The conceptual roots of the sacred sword were thought to originate in the kingdoms of Wu and Yue during the Spring and Autumn periods in ancient China.

・The concept of a sacred sword to vanquish evil (Bi Xie Sword for the elimination of evil) was first put into practice with sword use in Chinese Taoist rituals. These concepts then spread to Korea, as represented in the practices of the Hwarang, and later to Japan, further expanding upon the connected lineage amongst these three Far East Asian countries.

・The manner in which a sword’s sanctity was recognized followed ancient China’s Tian Ming Ideal (Mandate of Heaven), where stars were sacred and sanctified the sword through direct inscription. This practice was subsequently seen in the Korean Hwarang, where it was believed that through such sanctification a sword could channel mysterious powers from the stars or from Taoist gods, and in ancient Japan, where the mythical imagery that a sacred sword itself was brought down to Earth by deities was formed. This cites a particular transition from corporeal thinking to abstract thinking.

・The concept of a sword granted with divine power was formed in a flow of thinking stemming from ancient Korea and later connecting to Japanese sword ideology. This seemingly absurd belief in divine gifts was not as widespread in ancient China, where precise and rational thought was preferred, as opposed to Korea and Japan that had predispositions toward abstract thinking.

In budo and sports, most coaching words are abstract and intuitive, and their true meanings and scientific foundations are ambiguous. To understand complex movements scientifically, it is important to reduce them into simple models and to analyze them on the basis of mechanical laws. In this paper, as the first step in the theoretical study of movements, we consider the mechanics of bar models, which are applicable to various movements in budo and sports. In particular, we focus on the effects of inertial force on human movements, which have so far been overlooked. We also discuss the restorative force of muscles and gravity, which act in cooperation with inertial force. As a result, we found the mechanisms of some typical movements. For example, we interpret “kinetic link” as the combination of inertial force acting on a rigid body and restoring the force of muscles, and clarify the scientific meaning of “weight shift” in terms of the equivalence of gravity and inertial force.

Previous studies have reported that the alpha-actinin-3 (ACTN3) and angiotensin-converting enzyme (ACE) gene polymorphisms are associated with sports performance, muscle strength, muscle power, and endurance. Competitive judo requires high levels of muscle power, muscle strength, and endurance. However, thus far, associations between these gene polymorphisms and muscle power in judo athletes have not been reported. The purpose of this study was to investigate the relationship between ACTN3 and/or ACE gene polymorphisms and middle power in judo athletes. This study recruited 79 male judo athletes from a top-level university in Japan. Genomic DNA was extracted from the saliva sample taken from each athlete. Genotyping using either polymerase chain reaction (PCR)-restriction fragment length polymorphism or PCR was performed to detect ACTN3 (rs1815739) and ACE (rs1799752) gene polymorphisms. Each athlete also performed a 30-s Wingate anaerobic test with a resistance equal to 4.5% of the athlete’s body weight.

One-way analysis of variance revealed a significant difference in middle power relative to weight among the ACTN3 genotype groups (p<0.05). In other words, RX individuals showed significantly higher middle power than XX individuals (p<0.05). Moreover, middle power relative to weight was higher in individuals with the RR+RX genotype than in those with the XX genotype (p<0.05). However, there were no significant differences in the ACE genotype.

The results of the present study suggest that ACTN3 but not ACE gene polymorphisms may be associated with middle power in judo athletes.

This study created a 10-hours judo teaching program to conform with the nationwide implemented time for budo lessons in junior high school. In the teaching program, the instruction of “nage-waza” focused on “hiza-guruma”, “ō-goshi” and “tai-otoshi”, and from student’s “formative class value” and “skill value”, educational guidance tasks were examined. The subjects of the study were 40 second-grade junior high school students who were learning judo for the first time. The results of this study show the proficiency level of “tai-otoshi” was lower for boys when compared to “ō-goshi”, and lower for girls when compared to “hiza-guruma” and “ō-goshi”. This suggests that junior high school students who are taking a judo class for the first time, should be taught “tai-otoshi”.