The purpose of this study is to evaluate “Speed Uchikomi” as a form of strength training. We measured the following variables to evaluate the efficiency of this training, the heart rate according to the different pace of uchikomi, and the percentage of maximal oxygen consumption calculated from the heart rate and RPE. Endocrinological data, such as plasma lactic acid, ACTH and GH levels were also measured. The results were as follows: 1) We inferred from the cardiorespiratory response that “Speed Uchikomi” exceeds 70% maximal oxygen consumption when the frequency is more than once every 1.5 seconds. Therefore, when we use uchikomi as strength training, it should be done at a frequency of more than once every 1.5 seconds. 2) A gradual increase in the plasma lactic acid level, depending on the uchikomi frequency, was observed. “Speed Uchikomi” with a rate of more than once every 1.5 seconds gives a higher value than that of the lactate threshold or onset of blood lactate accumulation. From its energy metabolism, “Speed Uchikomi” is effective as endurance training. 3) “Speed Uchikomi” with a frequency of once every second increased the plasma ACTH level compared with the resting level. In other words, it is suggested that uchikomi which is a basic judo practice, has a significant influence on the endocrine system. 4) After performing “Speed Uchikomi” at the rate of once every second, the plasma GH level increased higher than the resting level, which means it has an anabolic effect. 5) The training rate of once every second is very exhausting and is expected to be more efficient than training at a rate of once every 1.5 seconds, but training like this without planning also carries a risk of overworking.

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  The athletic ability and morphological features of judo practitioners at different stages of growth need to be understood in relation to an individual’s biological maturity. Large, powerful atheletes have an advantage, especially in judo training. Bone age is a reliable indicator of biological maturity, and to discover and foster potentially talented judo practitioners, it is important to obtain measurements of bone age. Conventional approaches to bone age assessment have required X-rays, making it difficult to carry out bone age measurements on all candidates. To eliminate the need for X-rays, an ultrasonic bone age measuring device has recently been developed. In this study, we measured morphological features and physical fitness levels of young judo practitioners, and also measured bone age using this new ultrasonic device. The subjects were a group of 48 elementary school-age judo practitioners belonging to the “F Judo Club,” which is a training and fostering project supported by the Fukuoka Judo Federation. According to the Rohrer index, almost half of the practitioners were “rather fat,” demonstrating a trend toward obesity. The Rohrer index is more strongly correlated with percentage of body fat than with body weight, indicating a potentially effective measure for monitoring physical characteristics. Almost all the subjects were advanced in bone age relative to chronological age, showing that they tended to be early maturers. No difference in bone age was observed between the strong practitioners who were selected by the Fukuoka Judo Federation and others. In a subgroup of female subjects, bone age was correlated with back strength and vertical jump height ability. We conclude that bone age measurement, which allows a better understanding of the individual capabilities and physical characteristics of elementary school-age practitioners, would be very useful for the planning of training based on individual levels of development and growth.

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  This study focuses on British university students who were members of university kendo clubs in the U.K. and attempts to identify the factors that influenced them to decide to continue kendo after starting it.
  The subjects were 10 students who were selected by kendo instructors at university kendo clubs in the U.K. and the British Kendo Association, to participate in a three-week training camp with F university kendo club in Japan. They participated in semi-structured interviews lasting one to one-and-a-half hours, and talked about the reasons why they had started kendo and had decided to continue it, their experience of kendo and their viewpoint of kendo and so forth.
  There factors that influenced them to continue kendo were divided into four properties: 1) training in the U.K., 2) personal relationships kendo in the U.K., 3) kendo training in Japan, and 4) personal relationships made through doing kendo in Japan.
  To briefly describe the factors of each property, Property 1 included the fact that their training efforts were repaid and that they discovered objectives in their training. Property 2 included being influenced by their seniors and teachers, who were seriously practising kendo and other martial arts, and their friendly attitudes towards them. Property 3 included experiencing a difference in kendo style between the U.K. and Japan when they visited Japan and practised with high-level Japanese practitioners. Property 4 included being influenced by young Japanese practitioners with whom they built relationships as good friends outside and beyond the relationships in the Dojo.

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