Jigoro Kano (1860-1938), the founder of Kodokan Judo, became a member of the International Olympic Committee in 1909 and was instrumental in winning the bid for the 1940 Tokyo Olympics. The 1940 Games were not held due to the war, but in the run-up to the 1964 Tokyo Games, the belief was being formed that Kano wanted to include judo in the Olympic Games. However, the purpose of this research is to verify the hypothesis that Kano had no intention of including judo in the Olympics. The research method was to examine independently obtained audio data and literature that has not been covered so far. As a result, the hypothesis was largely confirmed, and it became clear that Kano believed that judo is different from sport. The reason Kano thought this way was because he had the belief that the purpose of judo was to realize that it had principles that can be applied to all aspects of life (meaning “maximum efficient use of energy”), and that competition was only one means to that end. Kano’s ideas were also understood and accepted by British judo practitioners, among others. After the war, judo became assimilated into sport whose goal was to win in competition, and as a result, it can be said that judo has lost its unique and diverse characteristics.

Judo instructors need to consider coaching tailored to the practical goals of athletes, and this study focuses on motivation. A previous study on judo examined the reality of motivation in judo practice based on free-response answers from judo athletes. However, in this study the reliability of that classification is considered insufficient. Therefore, this study aims to clarify the factor structure and reliability of motivation in judo practice based on the thoughts of college judo athletes through statistical analysis.

A questionnaire survey was conducted targeting college judo athletes to obtain responses regarding their basic attributes and motivation for judo practice. Exploratory factor analysis was performed using data on motivation for judo practice, and Cronbach’s α coefficient was calculated as an assessment of reliability for each factor. Additionally, correlation analysis and t-tests were used to examine the relationship between factor scores and attributes. As a result, five factors with 30 items were extracted regarding the motivation for judo practice among college judo athletes: “Goal/proximity” (α=.93), “Attractiveness as budo” (α=.87), “Personal growth” (α=.85), “Inertia continuation”(α=.85) and “Formation of career in judo instruction” (α=.90). There was a weak positive correlation or relatively strong positive correlation observed among all factors except for “Inertia continuation”. Additionally, the “Inertia continuation” factor showed a weak positive correlation only with the “Attractiveness as budo” factor. When conducting t-tests for each factor based on gender, significant differences were found in the “Goal/proximity”, “Attractiveness as budo”, and “Personal growth” factors. In all cases, males exhibited significantly higher values.

Comparison with a previous study suggests that the motivational factors for judo practice among college judo athletes are comprised of motivation as judo practitioners and motivation as student athletes. Furthermore, instructors are required to convey the appeal of judo and to tailor coaching to meet the goals of individual athletes.

In this study, the effects of torso impact on 20 university judo athletes during the recovery period of power output during intermittent exercise using a bicycle ergometer were investigated. Three conditions were set: an impact corresponding to the subject’s weight class was applied to the torso; a muscle exertion simulating an impact on the torso; and a control condition in which the subject rested in a seated position on the bicycle ergometer. The effects of the presence or absence of an impact on the trunk on intermittent power output were examined. The relationship between the power exerted and physical fitness characteristics was also examined, with the following results being obtained.

1. Intermittent power production under each condition showed a maximum value in the first set and a minimum value in the tenth set, and values from the second set onwards were significantly lower than the power exerted in the first set.

2. Power output values under the condition in which an impact was applied to the torso and under which muscle exertion was performed were significantly lower than those in the control, but no significant differences were observed between the two conditions.

3. When examining the relationship between power output and physical fitness characteristics when an impact was applied to the torso and when muscular exertion was performed, the correlation between maximum anaerobic power and anaerobic endurance was stronger under both conditions compared to the control.

These findings suggest that the cause of the decline in performance associated with intermittent power exertion is not due the impact to the torso, but the effects of the accompanying explosive muscular exertion. It also suggests that not only aerobic task performance but also maximum anaerobic power and anaerobic endurance contributed to the power exerted.

There exists a domain of education in Japan known as “social education”, (shakai kyōiku) which stands as a counterpart to school education. However, since Nakabayashi’s (1975) observations, there has been insufficient analysis of the historical connection between social education and budo (martial arts), leaving the question of how budo has come to be valued as a vehicle for social education largely unexplored. This study aims to clarify the social education function of the Dai-Nippon Butokukai (Greater Japan Martial Virtue Society), an organization known as the largest budo organization in modern Japan and one that had the most significant influence on the dissemination and establishment of budo.

This study examines the state of social education during the later period of popular education, as identified in the “One Hundred Years of Modern Japanese Education” compiled by the National Institute for Educational Research, along with prior research on the history of modern social education. It focuses on the activities of the Butokukai targeting youth after the conclusion of the Russo-Japanese War, which are highlighted as significant in earlier academic work. The study reanalyzes the arguments of Ōura Kanetake, the Butokukai president during that period, and clarifies the specifics of the organization’s activities. Based on the trends in social education during the later period of popular education, the research reveals the concrete functions of the Butokukai in social education.

As a result of analyzing the function of the Butokukai in social education during the later period of popular education, it became clear that the organisation played a certain role in this area. Notably, the encouragement and establishment of training halls (embujō) by the Butokukai was recognized as one of the recommended actions within social education administration at the time. Additionally, in several regions, there were cases where budo was used to correct the behavior and improve the morals of youth. Furthermore, it is suggested that the local branch offices and embujō established in rural areas may have functioned as places for youth groups to practice budo.

From this, it can be said that the Butokukai played an essential role in integrating budo education into modern education within the two domains of school education and social education. Behind this was the societal focus on youth as a problem and the existence of youth groups (seinen-dan), who were expected to play a role in regional improvement movements.

Judo, widely recognized as an Olympic sport, was defined as a “way” that maximizes the efficient use of physical and mental energy (ʻSeiryoku-Zenyo’). This path encompassed the principle of ʻJita-Kyoei’ (mutual prosperity), fostering harmony between individuals and society. While grounded in philosophical ideals, the teaching and execution of judo techniques required rigorous scientific analysis. This study investigated the biomechanics of seoi-nage, a highly effective and widely practiced technique, aiming to establish objective performance benchmarks. Nineteen experienced male judo athletes, including World Championship medallists, participated in this research. Using an 18-camera Vicon T10 system operating at 250 Hz and two Kistler force platforms sampling at 1000 Hz, the study captured three-dimensional motion data and ground reaction forces during the execution of seoi-nage. Performance metrics included the displacement of the uke’s center of mass (COM), total body linear momentum, and angular momentum. Key findings indicated that during seoi-nage, the uke’s COM showed a slight vertical increase during the turning phase and a significant decrease during the throwing phase, emphasizing forward and downward movements. Linear momentum analysis revealed substantial increases in resultant momentum, driven primarily by vertical and anterior-posterior components, with minor changes in the medial-lateral direction. Angular momentum analysis demonstrated significant increases, particularly in the medial-lateral direction, highlighting the critical role of rotational dynamics. Three hypotheses were tested: 1) The vertical component of uke’s momentum as a proficiency index, 2) The angular momentum of uke as a proficiency index, and 3) The mean moment of force as a proficiency index. Results indicated that the vertical momentum component was unreliable due to high variability and weak correlation with angular impulse. In contrast, angular momentum and mean moment of force were validated as reliable indicators of technical proficiency, correlating with effective execution. This study provides a biomechanical basis for evaluating and improving judo seoi-nage. By identifying critical metrics such as angular momentum and the moment of force related to angular impulse, the research highlights key indicators of technical proficiency. These findings offer valuable insights for developing targeted training programs aimed at enhancing performance outcomes. Future research should expand on these results by including more techniques and athletes, integrating advanced technologies to further refine analyses. These insights pave the way for more effective training strategies, contributing to the evolution of judo as a sport and discipline.