著者
杉本 祐太 前田 正登
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.26, no.2, pp.145-154, 2013-03-20 (Released:2019-09-02)
参考文献数
9
被引用文献数
1

Subjective effort is an adjustment in output performance, dependent on an athlete’s perception and it is an important factor in sprint training. To gain information about utilizing subjective effort in sprint training, this study investigates changes in sprint running movement due to the different subjective effort of athletes at various performance levels. The participants were 15 male collegiate sprinters, who were divided into high-level (n=7) and low-level (n=8) groups based on their personal best times in the 100 m dash. The participants performed 50 m sprints at five levels of effort ranging from 60% to 100%, with increases at 10% intervals. The final 10 m of each sprint was recorded by two high-speed video cameras to analyze each participant’s movement. The results are summarized as follows.     The decline in sprint speed at lower subjective effort was higher for the low-level group than high-level one. This was the reason why low-level group decreased swing back velocity of the leg with the change of knee joint angle increased below a subjective effort of 70%. And the achievement of sprint speed from a subjective effort of 90% to maximum effort was not practical because of knee extension during support phase. Moreover, below a subjective effort of 70%, the low-level participants’ movement during support phase differed from that of maximum effort sprint running. In contrast, the high-level participants’ movement was the same even a subjective effort of 60%.
著者
白木 駿佑 木越 清信
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.32, no.2, pp.253-264, 2019-03-20 (Released:2019-09-02)
参考文献数
15

This is the case study that the race pattern of a 400-m sprint was improved by “Affirmation”. The affirmation is a method of accomplishing goal and used in the world for business, education and so on. The purpose of this study was to obtain practical wisdom when using the affirmation to sports. A male sprinter had been having the problem of the 400-m race pattern and tried to solve it by the affirmation. Then, while correcting the affirmation sheet each time the race was done, the problem was solved four months from beginning to use the affirmation. He could not realize the image of the race pattern in the first half of the practical process. But in the second half of the practical process, he changed the contents of affirmation sheet greatly, realized the target model of race pattern which is the moderate deceleration type one month later. Besides, he had read the short affirmation sheet every day during this practice process. From this process, it was suggested that it is difficult to make the high-quality affirmation sheet in a short period from using it for the first time, and that it is necessary to use the short sentence involved realistic and clear image for continuous implementation of affirmation.
著者
中澤 翔 瀧澤 一騎 厚東 芳樹 山代 幸哉 佐藤 大輔 丸山 敦夫
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.31, no.2, pp.209-217, 2018-03-20 (Released:2019-09-02)
参考文献数
34

The purpose of this study was to clarify the relationship between running distance over an 8-month period and both 5000 m running performance and aerobic capacity (VO2max, VO2VT, running economy). The 8-month study period was divided into two segments of 4 months each. It was found that long-distance athletes could run 5000 m in about 15 min 30 s. The analysis also confirmed the following: (1) athletes that ran longer distances in the 8-month period had better 5000m times; (2) they had higher VO2VT; and (3) athletes whose distances were longer in the first half of the study period had better VO2VT and 5000m records in the second half of the period. The anaerobic threshold reached a higher level in runners with greater training distance, resulting in an improvement in race results. Furthermore, based on the fact that the distance run in the first four months effects on VO2VT and 5000 m running times in the latter four months, this study demonstrates the possibility of training effects occurring after a certain latency period. The results implicated that it was important to track running distances as an indicator of race performance.
著者
植松 伸之介 井口 祐貴 楠本 繁生 下河内 洋平 大城 章 横手 健太
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.31, no.2, pp.231-237, 2018-03-20 (Released:2019-09-02)
参考文献数
18

This study investigated the occurrence frequency of accelerations (Acc), decelerations (Dec), and changes of directions (CoD) during the actual handball game and their frequency under high intensity events (HIE) circumstances, using inertial measurement units (IMU).     Participants were female handball players in Japan. 10 players (Age: 24.7±2.3 years old, height: 167.0±8.1 cm, body weight: 65.2±6.1 kg) belong to womenʼs division of Japan Handball League (upper group), 10 top-level university players (Age: 20.6±0.8 years old, height: 165.1±5.9 cm, body weight: 61.0±5.6 kg) from the division 1 of Japanese university handball league (middle group), and 8 university players (age: 20.0±0.8 years old, height: 157.9±5.8 cm, body weight: 54.3±5.5 kg) from a team belong to division 2 of the league (lower group).     As a result, the upper group displayed the highest occurrence frequency in all items, the middle group was second highest, and lower group was the lowest. The result indicates that in competition sites, it is important to implement specializing training based on the understanding of the characteristics of handball as a sport and on the scientific knowledge that we could acquire from the actual games.
著者
梶田 和宏 川村 卓 島田 一志 金堀 哲也 八木 快
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.32, no.2, pp.171-187, 2019-03-20 (Released:2019-09-02)
参考文献数
55

This study clarifies the features of throwing motion to second base of professional baseball catchers.Eleven catchers of two Nippon Professional Baseball Organization teams were participants. Using the highest confidence data among analytical trials for throwing time, we defined it as ‘the time required from catching until ball arriving at second base with shortest time’. Following five characteristic features were revealed. 1) In time parameter, professional catchers have a difference in motion time (the time required from catching to release in amateur catchers), especially during the beginning phase having a relation with duration time (arrival time from the ball release to the second base), the throwing phase having a relation with the throwing time and release speed (speed average of ball speed of 3 frames after releasing the ball), and the grip changing phase having a relation with motion time. 2) Further, professional catchers have a tradeoff relationship between the motion time and the duration time as well as amateur catchers; and, particularly good professional catchers can shorten the duration time even while shortening motion time leading to shortening of the throwing time. 3) In stride parameter, professional catchers have a difference in the length of the pivot foot in amateur catchers, especially, the X component has a relation with the motion time while the Y component has a relation with the duration time, and the stride length is likewise; there was no relationship between all the items. 4) In release parameter, professional catchers maintain a higher projection height of the ball than amateur catchers and maintain the tendency of the projection angle to be lower, improving the throwing accuracy, especially the elevation angle is related to the duration time and the release speed, but the azimuth angle is likewise; there was no relationship between all the items. 5) In center of gravity of the body, professional catchers have a relation with the movement speed of the center of gravity of the body and the release speed as well as amateur catchers, but the moving distance of center of gravity of the body is likewise; there was no relationship between all the items.
著者
吉田 和人 山田 耕司 玉城 将 内藤 久士 加賀 勝
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.28, no.1, pp.65-74, 2014-11-20 (Released:2019-09-02)
参考文献数
16
被引用文献数
1

A notational analysis of 12,428 rallies in 149 singles matches at the London Olympic Games was conducted to clarify the characteristics of world-class rallies in table tennis. The number of shots played per rally, which was the sum of a correct service and correct returns, was measured. And the winning ratios of server and receiver were determined by the number of shots played per rally (Odd numbers indicate the server won the point, even numbers indicate the receiver won the point). The playing styles of the players were classified into all-round types and defensive types (chopper type), and the types of matches were classified into 3 by the combination of playing styles as: all-rounder vs. all-rounder (AA type), all-rounder vs. defensive (AD type) and defensive vs. defensive (DD type). The numbers of shots and the two ratios, and relations to both gender and type of match were considered. The DD type was excluded from this analysis because there were too few measured data. As a result, the mode of the number of shots for men and women was 3 each. The maximums for men and women were 38 and 60, respectively. The minimum for men and women were 0 each. The mean number of shots for women was significantly larger than that for men for AD type (p<0.01), and that for AD type was significantly larger than that for AA type for both men (p<0.01) and women (p<0.001). The mean winning ratios for servers for both men and women for AA type and AD type were all at the same level at about 55%, which were significantly higher than those for receivers of about 45% (p<0.01). Additionally, the evaluation criteria for the mean number of shots in a match, and those for the winning ratios of a server and a receiver were proposed. It was suggested that these results could be valuable for table tennis coaching.
著者
升 佑二郎
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.31, no.2, pp.219-230, 2018-03-20 (Released:2019-09-02)
参考文献数
12

This study compared the patterns of upper limb motion when delivering forehand (the hand holding the racket) straight/cross-court clear, drop, and smash shots from the backcourt in badminton.     Seven male badminton players, belonging to a team that was third in the All Japan Intercollegiate Badminton Championships, delivered these shots to record the pattern of motion in each case using MAC 3D System Cameras.     On comparison between straight and cross-court shots, the velocity of the wrist was significantly higher in the latter in all cases (p<0.05). The shoulder horizontal flexion angle was also markedly greater in the latter in all cases (p<0.05). On wrist motion trajectory analysis, the lateral (X-Z) plane at impact was shifted forward in the latter in all cases. Similarly, the frontal (Y-Z) plane was displaced inwards in the latter, while it was displaced outwards in the former from immediately before impact in all cases.     Based on the results, the velocity of the wrist may be higher at a greater shoulder horizontal flexion angle when delivering cross-court compared with straight shots. Furthermore, during the phase immediately before impact, the probabilities of straight and cross-court shots being delivered are high when the wrist moves out- (the distance from the trunk increases) and inwards (it decreases), respectively.
著者
吉田 康成 西 博史 福田 隆 遠藤 俊郎 橋原 孝博
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.28, no.2, pp.183-197, 2015-03-20 (Released:2019-09-02)
参考文献数
17

The purpose of this study was to investigate the read blocking techniques against quick attacks with combination attacks in volleyball. 28 occurrences of blocking motions in 4 games (Poland vs Iran, Poland vs Japan, Cuba vs Argentina, Cuba vs Serbia) from the 2011 Men’s World Cup Volleyball were analyzed by the Direct Linear Transformation Method.     The findings were as follows: (1) The number of occurrences of double blocking (Middle blocker with side blocker) was 11 (Right-side blocker 5 times, Left-side blocker 6 times). Most blocks were single blocks by the middle blocker.     The average of the highest finger-tip heights for blocking motions were right-side 2.80m, middle block 2.97m, and leftside 2.84m. (2) In 11 occurrences of when a middle blocker touched the ball, the average of the finger-tip height for the right fingertip was 2.91m (range: 2.76 to 3.04m), and the left finger-tip height was 2.85m (range: 2.70 to 2.99m). In 8 occurrences, the middle blocker took off -0.016 to -0.134 seconds before the quick spiker hit the ball. (3) When the quick spiker took off, the distance from the net to the middle blocker’s position averaged 0.90m (range: 0.38 to 1.91m). On the other hand, when the quick spiker hit the ball, the distance from the net to the middle blocker’s position averaged 0.66m (range: 0.31 to 1.34m). There was a significant difference between the distance at the time the quick spiker took off and the distance at the time the quick spiker hit the ball (p<0.01). Middle blockers took off 0.150 seconds later when their stance was usually wider than 0.6m.
著者
森本 吉謙 入澤 裕樹 坪井 俊樹 小野寺 和也 川村 卓
出版者
The Japan Journal of Coaching Studies
雑誌
コーチング学研究 (ISSN:21851646)
巻号頁・発行日
vol.32, no.2, pp.203-210, 2019-03-20 (Released:2019-09-02)
参考文献数
23

The purposes of this study were to investigate the relationship between competitive result and environmental factors in high school baseball. A questionnaire survey was conducted on 533 university students who belonged to the baseball club when they were in high school. The survey content was the following 11 items; 1. Highest competitive result, 2. Presence or absence of the sports recommendation entrance examination, 3. Presence or absence of the sports scholarship system, 4. Occupation of the head coach, 5. Presence or absence of the assistant coach, 6. Number of the assistant coach, 7. Occupation of the assistant coach, 8. Presence or absence of the selection system for enter the club, 9. Number of the members, 10. Type of school (public or private), 11. Presence or absence of the private facility. In case of high school duplication, only one answer was adopted, and other inappropriate invalid answers were excluded for totalization. Finally, 435 students were divided into national group (n=89), block group (n=82) and prefecture group (n=264), based on the best result of the team at the time of high school, and examined the relationship between the competitive result and each environmental factor. As a result, regarding the occupation of the head coach, the proportion of teachers in all groups was high, but in the other items, the relationship with the competitive result was indicated, and the possibility that the difference in these environments could affect the competitive result was shown.