As a result of global warming, including the heat island phenomenon, kendo practice by students and pupils during summer vacation is under threat. Based upon one climate index (Wet-Bulb Globe Temperature), it is recommended that kendo practitioners take rest breaks and drink plenty of water in the heat to avoid hyperthermic disorders. Currently, however, practitioners have no convenient means of evaluating if their rest time and water intake is sufficient or not. In the hope of finding a way to use the heart rate as a vital sign representing the threat of hyperthermic disorders, the heart rates and rectal temperatures of college kendo club members were monitored during midsummer practices. Their heart rates at maximal oxygen uptake in an ambient temperature of 25°C were also determined for reference. In a case where the highest recorded rectal temperature exceeded 39°C, the abrupt rise in rectal temperature was recorded during a jigeiko practice session together with a gradual increase in the lower levels of rapidly fluctuating heart rates. Such a heart rate response is considered to be a physiological response to an elevation of the core body temperature. Therefore, we suggest that those who practice kendo in the heat should self-check themselves to determine their likelihood of falling victim to hyperthermic disorders by paying attention to their heart rates during brief breaks between physical action during practice. In addition, as the measurements we took indicated that the highest rectal temperature was attained at the end of a contiguous practice sessions, one could probably check retroactively for the threat of hyperthermic disorders by taking an axillary temperature using an ordinary clinical thermometer.
The purpose of this study was to clarify the factor structure of the reasons for the continuation of judo practice among adult judo-ka, and to understand the way attitudes change according to age and years spent practicing judo. The subjects were 186 male judo-ka aged 18 to 80 years at a sports center in Tokyo. A control group consisted of 58 males aged 18 to 59 years who participate in other sports at a sports centre. The subjects were asked to answer a questionnaire containing 50 items related to the reasons for continuing to exercise, such as physical, social, perceptual, mental, and emotional reasons. Five factors were extracted from the two groups. Three of the factors: “character development,” “a favorable impression,” and “improvement of physical fitness” were common to both groups. Factors unique to each group were “improvement of mentality” and “attracted to martial arts” in the judo group, and “personal goals” and “recreational purposes” in the non-judo group. It was clear that the factorial structure in the judo group was different from that in the control group. That is, the reasons for continuing training in the judo group contained factors concerned with Budo, but did not contain “recreational purposes” or “personal goals.” There were significant positive correlations between age and years of training, and factors such as “character development” and “improvement of mentality.” These factors are related to the maturing of human nature according to age or years of training, and it suggests that maturing or continuing to practice judo over the years are able to aid judo-ka in character development.
The purpose of this paper is to use historical materiology to study the reliability of the personal history of Toru Shirai as described in Tenshinden Shirairyu Heiho Tsukaikata, written by Shirai’s disciple Okunojyo Yoshida. To do so, we clarify the descriptive form and contents of the biography, the source of the information used by Yoshida to write the history, and we verify the truth of the content. The conclusions of this study can be summarized as follows: 1) The biography of Toru Shirai as described in Tenshinden Shirairyu Heiho Tsukaikata is based on what Shirai himself wrote in Heiho Mitchishirube. However, information about Shirai’s birth and social position were added to the beginning, information about his experiences that occurred after Shirai wrote Heiho Mitchishirube were added to the end, and anecdotes about his kenjutsu practice after age 8, including his matches against swordsmen from different schools, were inserted in the middle of Tenshinden Shirairyu Heiho Tsukaikata. 2) The added information is described in concrete terms, and some of it must have been communicated directly from Shirai to Yoshida. Judging from the related sources, Yoshida seems to have kept records of what Shirai said. Therefore, details of Shirai’s birth, social position, and anecdotes about his kenjutsu practice and so on must have been described based on Yoshida’s records. In that sense, the added information can be said to have a fairly high reliability as a historical source. 3) As a result of the detailed verification of the truth of Shirai’s birth, social position, anecdotes about his encounter with the ascetic Tokuhon, and other matters, it has been proved that most of the information is true. We can, therefore, conclude that Shirai’s personal history in Tenshinden Shirairyu Heiho Tsukaikata, written based on Heiho Mitchishirube that Shirai himself wrote and what Shirai said, has a fairly high reliability as a historical source from the standpoint of historical materiology.
This paper describes the invention of a sumo mat to secure safety for schoolchildren doing sumo in physical education classes. The first advantage of the sumo mat that we invented is that safety is secured by the difference of height of the mat. The second advantage of the mat is that it can be laid down easily and quickly anywhere, e.g. in a gymnasium, auditorium, classroom, or budo hall. The authors believe that the invention of a sumo mat will provide beginners—even small children—with a safe environment in which to practice sumo.