The term “psychological skills” used in the previous study refers to the psychological abilities that are necessary for athletes to perform well in competitions. The purpose of this study was to examine the aspects of psychological skills that come from the practice forms and methods valued by judo players’ in their daily practice routines. The subject of the survey were 369 judo players (gender: male = 253, female = 116, age: junior high school = 95, high school = 90, college = 89, adult = 95). Data was collected during October and November 2013 psychological skills evaluation scale that had been developed for judo players. This scale is composed of four factors (“tactical thinking ability”, “volition for practice”, “reception of others”, and “support of others”) and 23 items. In order to examine the aspects of judo players’ psychological skills, variance analysis was carried out on the data obtained from this study. Regarding the results of the investigation of practice forms (basic practice and applied practice, both practices) valued by judo players, those that valued both types of practice, not either basic or applied, possessed better psychological skills. In addition, for each type of practice forms, different psychological were acquired by the judo players. Regarding the practice methods (tachi-waza, ne-waza, both methods) valued by the judo players, it was clear that it had a favorable effect on their psychological skills if the judo players the judo players valued both types of method, not either tachi-waza or ne-waza. In addition, according to each practice method, the skills that the judo players acquired are different. In conclusion, according to the difference in the practice forms or methods that judo players’ value, significant differences were found in the psychological skills that they possess.
The present study aims to obtain findings on the prevention of obesity in elementary school competitive judo players by investigating the relationship between body weight and body composition indices, such as the fat-free mass index (FFMI) and fat mass index (FMI). We included 581 fifth and sixth grade male and female judo players as our subjects and measured their height, body weight, and body fat percentage. We calculated their respective fat-free mass (kg) and fat mass (kg) from the data and then calculated each student’s FFMI and FMI by dividing their respective fat-free mass and fat mass by the square of their respective heights (m). The results indicate that FFMI significantly increased in boys with an increase in weight class for groups with a body weight of less than 60 kg. No statistically significant differences in FFMI were noted in groups with a body weight of greater than 60 kg. In contrast, we identified statistically significant differences in FMI across all weight classes. FFMI significantly increased in females with an increase in weight class for groups with a body weight of less than 50 kg. However, no statistically significant differences in FFMI were noted in groups with a body weight of greater than 50 kg. Similar to the male subjects, we identified significant differences in FMI across all weight classes in the female subjects. In conclusion, generally a weight gain to greater than 60 kg in boys and toward 50 kg in girls among elementary school competitive judo players suggests that increases in fat-free mass reach a plateau and that fat mass could be the active agent.
This research aimed to clarify whether the International Judo Federation Refereeing Rules 2014-2016 (New-IJF Rules) facilitated dynamic judo in the All-Japan Judo Championships (AJJC). Therefore, Kodokan Judo Refereeing Rules’ tournaments (KDK Rules’ tournaments), International Judo Federation Refereeing Rules’ tournaments (IJF Rules’ tournaments), and New-IJF Rules’ tournaments were compared. The following results were obtained. Regarding winning contents, in the New-IJF Rules’ tournaments wins by ippon significantly increased whereas wins by superior performance significantly decreased when compared to KDK Rules’ tournaments. Furthermore, for winning methods, points from techniques significantly increased but judges’ decisions significantly decreased in the New-IJF Rules’ tournaments when compared to KDK Rules’ tournaments. However, concerning total points, the results did not show significant differences. As a result, this research confirmed that the New-IJF Rules increased the wins by ippon and points from techniques in relation to winning methods, and decreased the superior performance and judges’ decisions in the AJJC. These findings suggest that the New-IJF Rules facilitated dynamic judo in the AJJC.
Many people think that any research in natural science should be based on experimental data and that theoretical study alone is unworthy of science. We point out some popular misunderstandings in natural science research, and discuss the importance of theoretical study in budo and sports.