In October 1933, the Ministry of Education founded the Exercise Medical Consultation Office (EMCO). In an attempt is to revisit the historical image of sports policy in prewar Japan, this study sought to clarify why and how this national policy was realized and to examine the nature of its activities from the perspective of the Ministry officials directly involved in its implementation.
Previous studies have evaluated the sports policy of the 1930s as a “physical education policy” that regulated sports activities to improve the national physique and cultivate the national spirit, ultimately leading to the decline and suppression of sports in the 1940s. However, the historical image of this policy was derived by positing the sports policy and its officials as a means of advancing nationalistic intentions. Therefore, the present study examined the process of the EMCO’s foundation and activities separately from the “physical education policy” framework by focusing on the thoughts and actions of EMCO officials, with the aim of relativizing the views of previous studies’ in the context of the contemporary development of sports medicine.
The EMCO was founded on the basis of the “Rational Promotion Policy for Physical Education Exercise” (1930), reflecting the aspirations of sports medicine scholars for an institution in which athletes could be examined by doctors with a deep understanding of sports and sports medicine in order to create an environment that would motivate athletes to continue their sporting activities. Thus, the EMCO did not aim to adjust or control the athlete’s mind and body based on the objectives of physical education, but rather to provide a medical consultation that would examine each individual’s sporting history and physical condition in a specific and comprehensive way. The Ministry of Education officials who promoted this policy had a view of sports that resonated with those involved in private sports organizations. Having expertise and connections in sports and medicine, they hoped to apply and develop sports medicine in a context that was different from the national intentions of ideological guidance and improvement of the national physique. Therefore, this policy created no conflict between the Ministry of Education officials and private sports organizations, and even in the late 1930s, the Ministry of Education developed a policy to encourage sports activities based on personal interests and concerns from the perspective of sports medicine.

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This study aimed to examine the Sasaki-Sebata controversy between Kentaro Sasaki and Shiro Sebata, said to have been the first postwar dispute regarding the practice of physical education. Previous studies have examined mainly the practices of Sasaki and Sebata as well as the differences between them, but in terms of actual historical proof, the positioning of the 2 has been quite ambiguous. By contrast, the present study examined the essence of physical education as considered by Sasaki and Sebata from a historical perspective and sought to clarify their fundamental differences. According to Sasaki, the purpose of physical education was labor, whereas Sebata considered that physical education facilitated a physically active lifestyle separate from labor. Despite this difference, when exploring the practices of the 2, it was found that both had similarly placed value in the aim of breaking away from alienated physical education and maintaining ties with society by fostering the development of children who would be able to change it.

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This study sought to redefine the concept of exercise, and to establish its correct Japanese term:jinryoku. In contemporary Japan, exercise is recognized as easy-access bodily movement for maintenance of individual health or improvement of physical skill.
Historically, however, research on the history of philosophy has tended to consider exercise in the context of morality and ethics related to individual well-being.
Therefore, reconsidering the concept of exercise and translating it into a suitable Japanese context might help to advance the philosophy of sport in relation to culture.
Applying the theory of “spiritual exercise”, the 20th century French philosopher Pierre Hadot (1922-2010) redefined the concept of exercise as actions directed toward a better lifestyle, which can be best expressed as the Japanese term jinryoku. Whether and how far the concept of exercise can serve as a fundamental principle of sports and culture philosophy awaits further discussion.

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This study examined the relationship between velocity loss and differences in the intensity of squat exercise. Twenty-two male college students who were exercising actively performed repetitive lifting during squatting exercise within 5 different velocity ranges. It was found that the slope of the velocity decrease was large in the medium-intensity to high-intensity range. At low intensities, the decrease in velocity was moderate. It was also clear that the degree of fatigue varied greatly depending on the number of repetitions and the duration of exercise at the same rate of velocity loss. In addition, higher exerted power was observed at low and medium intensities. The minimum power was approximately 70% of the maximum peak power. This suggests that in velocity-based training, the acceptable range of the velocity reduction rate relative to intensity may differ in order to control excessive fatigue and obtain the desired training effect.

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The purpose of this study was to clarify the causal structure for achieving high walking speed and to obtain useful information that would contribute to race–walking coaching. Ninety–seven male race–walkers with a wide range of performance level were analyzed using motion analysis involving 3–dimensional direct linear transformation with 2 video cameras. Variables such as walking speed, step length, step frequency, joint angle, and segment angular velocity were obtained from the video images in the early phase of 3 20–km race–walking competitions. Several indices were calculated from spatiotemporal variables using the height of each athlete, and we examined the relationships among these indices. Based on these relationships, a causal structure model including the walking motion variable was developed, and the validity of this model was examined using structural equation modeling (SEM). The main results were as follows.
The walking speed index and step length index showed a linear relationship with their component variables, whereas the pitch index showed a curvilinear relationship with the contact time index and flight time index. This indicated that the relationship between the pitch index and its component variables varies depending on performance level. In addition, the walking speed index was moderately to strongly correlated with both the step length index and the pitch index. Furthermore, the step length index was strongly correlated with the flight distance index and the pitch index with the contact time index. These correlations indicate that improving the flight distance index and decreasing the contact time index are important for achieving a high walking speed.
The validity of the model developed in this study was high, indicating that the model represents the actual relationships among the various indices and walking motion.
The model revealed that a large angular velocity of shoulder flexion on the supporting leg side and angular velocity of swing forward the recovery thigh at ground contact, and little anterior tilt of the torso at toe off, would alter the subsequent motions and increase the walking speed. The model developed in this study has revealed the causal structure for achieving high walking speed in race–walking as a series of motions, which may provide useful information for coaching while considering walking motion as a whole.

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In this study, we developed a university student version of the student athlete’s edition of the sports organization commitment questionnaire. In Study I, we first conducted a web questionnaire survey of 754 physical education majors, collected and analyzed items that could measure organizational commitment in sports, and attempted to create the student athlete’s edition of the sports organization commitment questionnaire. First, we conducted exploratory factor analysis to confirm the factor structure of the university student edition of the sports organization commitment scale.
A six–factor structure (18 items) of “attachment commitment”, “membership commitment”, “achievement motive commitment”, “normative commitment”, “internalization commitment”, and “continuance commitment” was extracted.
Cronbach’s α coefficients were at a level that met the criteria. Confirmatory factor analysis was performed on the solution, and the value of the degree of fit that met the criteria was derived. Next, in order to clarify the reliability of the university student version of the sports organization commitment scale, and whether the scale is related to club behavior and awareness, we examined the validity of the criteria using the existing scale. In Study II, we also examined the characteristics of organizational commitment among university athletes. As a result, men scored significantly higher on “attachment commitment ” than women, and in group sports, “achievement motive commitment” and “internalization commitment” were higher than in individual sports.
In addition, those who had a role in the club scored significantly higher on “attachment commitment” and “internalization commitment” than those who did not. Finally, regulars scored significantly higher on “attachment commitment” than non–regulars.
From the above, the student athlete’s edition of the sports organization commitment questionnaire was constructed, and it was confirmed that the organizational commitment of university athletes is affected by gender, sport, club role, and competition level.

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The purpose of this study was to identify the main factors influencing the success to receive and turn with the ball “between the lines” in football and to construct a regression equation to predict turn success probability. The sample consisted of 1,260 plays in which a pass was received “between the lines” at the 2018 FIFA World Cup held in Russia. The play data was collected using game performance analysis. In the statistical processing, the main factors influencing turn success probability in the “between the lines” of football were clarified using logistic regression analysis. The factors influencing the success probability of a turn were the presence or absence of visual exploratory activity, the type of pass, i.e., a grounder, a bound, or a lob, the receiver’s position, the distance from receiver to first defender at the moment of receiving the pass, the distance to the first midfielder, the distance from receiver to first defender at the moment of passer’s passing, the distance to the first midfielder, the pressing speed of the first defender, the pressing speed of the first midfielder, the pass distance, the pass angle, the pass speed, and the number of forward-looking players present between the lines. In addition, a regression equation was constructed to predict turn success probability by combining the odds ratios of the main factors. It was verified that the regression equation can be used to predict turn success probability in the “between the lines” with high accuracy (accuracy rate 77.1%). Future work includes using the regression equation to clarify the usefulness of turn success probability from comparative verification with the performance made after the turn.

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For appropriate risk management in schools in the context of physical education activities, there is an increasing need for communication between teachers and parents in order to achieve a consensus. The purpose of this study was to clarify the difference in the perception of risk posed by physical education activities between elementary school teachers and parents. To this end, 106 elementary school teachers and 102 parents responded to a risk image scale comprising 9 items and a risk perception scale comprising 4 items related to 9 different physical education activities. The results of three–mode factor analysis using the Tucker 1 model indicated that the risk image scale was aggregated into 3 dimensions–“educational significance”, “dread”, and “controllably known”–while the risk perception scale was aggregated into 2 dimensions–“risk evaluation” and “need for response”. Examination of the differences between teachers and parents for each variable revealed that teachers tended to rate educational significance, dread, risk evaluation, and need for response higher than parents. In addition, teachers tended to show relatively larger differences in risk evaluation for each activity than did parents. Multiple regression analysis revealed that dread influenced risk evaluation, and that both dread and educational significance influenced the need for a response. This indicated that the difference in risk perception between parents and teachers was attributable to a difference in educational significance and dread. These results suggest that, in order to improve risk communication in schools, it is necessary for teachers and parents to match their degree of educational significance and dread, respectively.

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The purpose of this study was to obtain suggestions on how to promote bidding and hosting of World Championships in Japan by analyzing changes in the number of World Championships, and the policy characteristics of the countries where the number of World Championships has increased and decreased. The numbers of World Championships held in the periods 2001–2010 and 2011–2020 were compared across geographical regions, event categories (Olympic and Paralympic (Oly/Para) sport, non–Olympic and Paralympic (non–Oly/Para) sport), and age groups (Senior, non–Senior). The results showed an increase in the total number of all World Championships held in Western Europe and Western Asia, and all World championships and all Oly/Para sport World Championships held in Eastern Europe. There was also an increase in the total number of World Championships, and all and senior Oly/Para sport World Championships held in Central Asia. On the other hand, there was a decrease in the number of senior non-Oly/Para sport World Championships in Western Europe, all non–Oly/Para sport World Championships, and all Oly/Para sport and all non–Oly/Para sport World Championships held in Australia and New Zealand. These findings indicate that some countries have significant influence on the number of World Championships hosted on each continent. The countries where the number of World Championships is increasing utilize the major sporting events as an opportunity to revitalize economic and social activities, science and technology policies, and to establish and improve their international status and image. Among the countries where the number of World Championships has decreased, one contributory factor might be changes to governmental policies regarding the hosting of major sporting events, as bidding for the rights to host such events has become increasingly competitive. Furthermore, strong positive correlations were found between the number of host cities and the number of World Championships and sports held in each country for both the 2001–2010 and 2011–2020 periods. Countries that host many World Championships may be implementing various strategic initiatives by taking into account the characteristics and needs of cities that could potentially host major sporting events. Furthermore, in developing strategies for bidding and hosting major sporting events for countries and cities, the event portfolio theory and the concept of leverage might be useful.

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This study attempted to clarify the occurrence of sendings off and temporary suspensions in men’s rugby sevens, the correlation between numerical imbalances and game performance, and to obtain strategic insights for tactical planning during those periods.
A comprehensive analysis of 11 tournaments within the 2022–23 World Rugby Sevens Series yielded several key findings: 1) The incidence of sendings off and temporary suspensions was approximately 1 in every 3 matches (0.36 occurrences per match), with a notably high frequency in the latter half of the match, specifically after 3 minutes and 30 seconds (35.1%), and predominantly in teams with a lead of 14 points or greater (16.0%). 2) In over 60% of matches featuring a temporary suspension, the team with a numerical advantage succeeded in scoring at least 1 additional try. There was a marked increase in tries resulting from kick–offs, scrums, and tap kicks. The percentage of winning kick–offs and the subsequent try–scoring rate surged by over 40% due to the decreased number of opposing players. A significant increase in the tackle success rate to 60% was also observed. 3) Conversely, in approximately 30% of matches, the team at a numerical disadvantage during a temporary suspension struggled to generate offensive play. A decline in the frequency of line breaks during offensive phases and an escalation in line breaks conceded during defensive phases were also noted, attributable to the reduced number of players on the disadvantaged team.
The findings of this research highlight aspects that are distinctly influenced by numerical imbalances. Given that a team with fewer players during a temporary suspension faces comprehensive disadvantages in both offensive and defensive capacities, it is imperative to select strategies that minimise play time during such suspensions, considering the score margin and time remaining in the match. Moreover, the investigation revealed specific benefits for the team with a numerical advantage during a temporary suspension, offering invaluable insights for formulation of tactical approaches in anticipation of numerical imbalances.

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　Motion capture systems using infrared cameras (Marker-Based MoCap) are frequently used in biomechanics research because they can accurately measure the 3D coordinates of reflective markers. However, if reflective markers cannot be fixed to the body or data cannot be collected from a large number of subjects within a short period, Marker-Based MoCap cannot be used, making it necessary to collect movement data without using markers. The purpose of this study was to develop a markerless motion capture method using a human body model and a neural network for silhouette extraction, based on open source data. We aimed to compare its accuracy with that of previously developed markerless motion capture methods, and to determine whether its performance was superior. Thirteen subjects walked at arbitrary speeds, and their movements were captured by 8 RGB cameras. Based on the obtained images, the 3D coordinates of the joint centers were calculated using the proposed method of matching the silhouettes with the human body model. The mean error of the joint center was less than 30 mm for all joints, except for the hip joint, which had an error of 38.7 mm. Comparison of the proposed method with markerless motion capture using a 3D scanner revealed that the former was less accurate for most joints. Therefore, in experimental environments where a 3D scanner is available, the proposed method should not be used. The accuracy of the proposed method was higher than that of a commercial markerless motion capture system (Theia 3D), except for the hip and hand joints. Therefore, investigators should rationally choose between the 2 methods according to the purpose of the research and the experimental environment. In comparison with markerless motion capture using an open source (e.g. OpenPose), the proposed method was more accurate, except for the hip joint, suggesting it would be better to choose the proposed method in most cases. The accuracy of the proposed method was particularly low at the center of the hip joint. Therefore, it would be necessary to improve accuracy for the hip joint by identifying the superior anterior iliac spine, superior posterior iliac spine, and greater trochanter on the human body model.

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　The purpose of this study was to investigate the relationships between the shoulder kinetics of pole vaulters during pole bending and the isokinetic strength of the shoulder, and to clarify the characteristics of the shoulder kinetics. Three-dimensional coordinates of vaulters' body landmarks were recorded using a motioncapture system. The box reaction force was measured using a force plate placed under the planting box. The joint force and joint torque acting on a hypothetical shoulder joint were estimated using inverse dynamics calculations for a synthetic upper limb segment, assuming both upper limbs to be a single segment. The pole bending phase was divided into 3 sub-phases, “take-off,” “drive,” and “swing,” in order to determine the unique characteristics of shoulder kinetics during vaulting. Isokinetic tests were conducted to measure shoulder strength.
The main findings were as follows:
1) The impulse of the box reaction force of the Y-component (F_Y) in the pole bending phase showed a significant negative correlation with the elastic energy in the pole at maximum pole bending (r=-0.56, p<0.05).
2) The impulse of F_Y increased during the pole-bending phase, approximately 45% of this increase occurring during the drive phase and 48% during the swing phase.
3) The angular impulse of the torque of the hypothetical shoulder joint in the drive phase showed a significant positive correlation with the impulse of F_Y in the same phase (r=0.67; p<0.01). In contrast, the impulse of F_Y showed a significant positive correlation with the impulse of the joint force of the Y component in all subphases (take-off phase r=0.88, p<0.01; drive phase r=0.99, p<0.01; swing phase r=0.96, p<0.01).
4) The maximum extension torque of the hypothetical shoulder joint in the pole-bending phase was not significantly correlated with the maximum isokinetic concentric extension strength, maximum isokinetic eccentric extension strength, or maximum isokinetic internal and external rotation strength of the shoulder joint.
　These results indicate that exertion of the joint force and joint torque of the shoulder during vaulting contributes to pole bending. However, the magnitude of the shoulder joint extension torque during vaulting was not related to the isokinetic strength of the shoulder joint.

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Walking to school is an important opportunity for children to engage in physical activity. In rural areas, however, an increase in commuting by bus has reduced the extent of walking to school. A recent initiative, known as remote drop-offs (or “park and walk”), has advocated placing bus stops slightly further away from school to create a walking section of the route taken by students. In Japan, the Kakeya Elementary School in Unnan City, Shimane Prefecture, has been implementing this initiative since 2009. The aim of the present study was to clarify the process of implementing such remote drop-offs at the school, as well as the factors facilitating or hindering it. Semi-structured interviews were conducted with the school principal, vice-principal, parents, educational support coordinators (city government employees), and a former researcher from the Unnan City research center, who were all involved in the introduction of remote drop-offs. Documents were collected before and after the introduction of the scheme. On the basis of the survey findings, the process of transition was clarified. Furthermore, factors promoting or hindering the scheme were assessed using the Consolidated Framework for Implementation Research. The survey findings indicated that the factors effective for helping to set up the walking segments included parental requests for their establishment before the school merger, active communication between the school and parents after the merger, and the importance of proposals from experts (researchers). The study identified additional promotion factors such as the physical location of bus stops, which could pose operational challenges, cooperation of the community in ensuring safety by installation of crosswalks and signs without extra costs, and police monitoring. Furthermore, the placement of an educational support coordinator at the school streamlined the administrative tasks. Factors that proved inhibitory were the securing of appropriate locations for bus stops, and provision for disasters. In conclusion, the study findings provide valuable information for promoting remote drop-offs as a measure for preventing physical inactivity among children.

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Self-regulated learning entails active participation in the development of academic and sports expertise. Nonetheless, clarifying its significance is essential. This study attempted to clarify the feasibility of self-regulated learning by examining the independent and interactive influences of both individual and environmental factors: specifically, sports ability beliefs and coaching style perceptions. We subjected 303 university student athletes to multiple regression analysis using the self-regulation of learning in sports scale score as the dependent variable, sport ability beliefs (incremental or entity) and coaching style perceptions (athlete-led or coach-led) as explanatory variables, and skill level (Japan national level or lower), sport type (team or individual), and sex (male or female) as control variables. The results revealed significant main effects on planning and effort, indicating that promoting self-regulated learning benefits from encouraging athletes to adopt incremental beliefs and an athlete-led coaching style. Additionally, significant second-order interactions for evaluation/reflection emerged, demonstrating a positive effect of incremental beliefs on evaluation/reflection among men, irrespective of coaching style perceptions, and a negative effect among women, who perceived a coach-led practice environment. These findings suggest that strategies to promote self-regulated learning should be tailored to account for specific treatment interactions.

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This study attempted to clarify how the process of “unlearning” occurs in parasports, particularly in sitting volleyball. It also explored the possibility of inclusion in sports and what it means for able-bodied people to experience and play parasports. The term “unlearn”—as proposed by G.C. Spivak—is an essential concept in inclusive societies.
First, we present an overview of the literature related to anthropology, Kyosei studies, and unlearning as a facet of diversity education, examine the concept of unlearning, and cover the concrete and practical difficulties that arise in parasports. We then examine the possibility that learning and abandonment could resolve these difficulties. We specifically refer to the literature on the philosophy of sports and adapted sports as well as interviews with university students and athletes with parasports experience. As exemplified in the present example of sitting volleyball, we find that unlearning is a process by which able-bodied participants become members of the team. The first step entails learning about players with disabilities, and then “forgetting” about their disabilities as part of the unlearning process. This finally enables both the able-bodied player and player with disability to transcend superior/subordinate relationships, such as “seeing”/“being seen” or “understanding”/“being understood.”
If such unlearning can be achieved across sports, we can claim that parasports truly contribute to greater diversity and inclusion in society. In practice, however, absolute inclusion is not easily achievable because sports are characterized by emphasis on ability, and thus, exclusion. In particular, given that some individuals hesitate, give up, or leave without the knowledge of the participants, the possibility of exclusion borne out of defeat and hopelessness must not be overlooked.

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The purpose of this study was to compare the grasping characteristics of judo and non-judo athletes by measuring their handgrip, strength exerted by active isometric contraction (grasp), and strength exerted by eccentric contraction against a passive load (breaking grasp) strength using a unique measuring device. A total of 41 female athletes (22 judo athletes and 19 non-judo athletes) participated. The handgrip, grasp and breaking grasp strength of the dominant hand were measured. For this, the participants grasped the grasping part while in a seated posture with the elbow joint flexed at 90° and the upper arm held close to the body and applied an exerting force. During the test, the participant’s upper arm and trunk were bound and immobilized. The grasp strength was defined as the maximum value at approximately 3–4 s from the time the participant started exerting force by grasping the tool until the wire began winding. The breaking grasp strength was defined as the maximum value from the time the motor started to wind the wire to the time when the participant removed her hand from the grip. The results of the analysis revealed the following: (1) The handgrip and grasp strengths were comparable between the judo and non-judo athletes, and relative handgrip strength per body weight was lower in judo athletes than in non-judo athletes. (2) Breaking grasp strength was superior in judo athletes relative to non-judo athletes. (3) The judo athletes had a higher relative value of breaking grasp strength to grasp strength than non-judo athletes. These results suggest that judo athletes are characterized by a superior breaking grasp strength of passive exertion as a result of judo practice.

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Aerobic exercise has been reported to improve cognitive function in children. Among such functions, the extent to which aerobic exercise affects executive functions, such as working memory and inhibitory control, which are deeply related to academic performance, is an important topic in childcare and education. However, most of the existing research has focused on typical aerobic exercises like jogging. As it is difficult to encourage children to participate in monotonous exercises like jogging for a prolonged period, this poses a barrier to application of research findings in childcare and educational settings. Here, we focused on trampoline exercise, which is more enjoyable for children than typical aerobic exercise, and examined its impact on executive functions. The experiment was conducted using a crossover design with 25 healthy kindergarten children aged 3 to 6 years. Cognitive (1-Back, Go/No-Go, Flanker and Simple reaction time task) and saliva collection were conducted before and after the intervention. In the trampoline condition, participants engaged in 10 minutes of trampoline exercise in the playground, while in the waiting condition, they played freely in the playroom. The results showed significant increases in both cortisol and immunoglobulin A levels only in the trampoline condition. In terms of cognitive parameters, significant changes were observed only under the trampoline condition. These included a significant reduction in the inverse efficiency score of the 1-Back task (p = 0.044), which reflects reaction time adjusted for accuracy, an improvement in the accuracy of the Go/No-Go task (p = 0.023), and a reduced reaction time in the simple reaction time task (p = 0.019). In contrast, no such improvements were observed in the waiting condition (p > 0.05). These findings suggest that short-duration trampoline exercise, which is enjoyable for children, can improve executive function. On the other hand, when comparing changes in these cognitive measures from pre- to post-intervention between conditions, no parameter showed significant differences between the 2 conditions. Therefore, it should be noted that the effects of trampoline exercise on cognitive function cannot be interpreted as being significantly greater than those under the waiting condition. Further validation from a wide range of perspectives is required to develop methods for long-term intervention using trampoline exercise that are beneficial to childcare and early childhood education.

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A study was conducted to examine the importance of making national competitions a milestone in the development of athletes, thus contributing to improvement of international competitiveness. The study focus was the National Sports Festival, which is included in the sport basic plan, as it helps to improve competitiveness by discovering and developing promising athletes. The research attempted to clarify to how national sports federations with excellent results in international competitions position national competitions in the athlete development pathway. Data were collected through semistructured interviews with staff involved in the management of national sports federation competitions and those responsible for athlete development. Steps for Coding and Theorization (SCAT) were used to analyze the collected data. Although interpretations of raw data can only be superficial, SCAT analysis allows the data to be decontextualized and recontextualized by constructing codes extracted from the context into a storyline, enabling in-depth meanings to be interpreted. The results suggested that for national competitions to function as a factor promoting athlete development, the following points should be considered: 1) they should identify promising athletes; 2) they should be linked to international competitions; and 3) they should overcome the differences in perspective between national sports federations and local stakeholders.

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“Base running” (BR) in baseball is a factor related to offense as well as hitting. A superior BR performance increases the on-base percentage and provides score run opportunity. Running routes are an important factor in BR. However, the relationship between a running route and time in BR is unclear. The aim of the present study was to clarify the relationship between running routes and time in BR from the home plate to second base. Fifteen male collegiate baseball players performed BR to second base from the home plate and 54.86 m of straight sprinting. The BR time, speed and route between the home plate and first base (HF) and between the first base and second base (FS) during base running were calculated using the three-dimensional panning DLT method, respectively. Indicators of the calculated running route in each section were 1) the vertical distance (VD) from the line between bases when the body position was projected on the ground, and 2) the position that recorded the maximum VD (VDp). The maximum speed in the HF section was 8.0±0.3 m/s, but in the FS section, the speed decreased to 6.9±0.4 m/s at minimum. On the other hand, there was no significant difference in the maximum speeds between HF and FS (7.9±0.4 m/s). The BR time to the second base showed a significant correlation with the maximum VD in HF (r = -0.631, p = 0.012), VDp in HF (r = 0.633, p = 0.011), the rate of deceleration from HF to FS (r = 0.612, p = 0.015) and the maximum speed in FS (r = -0.794, p <0.001). Besides, straight sprinting time was significantly correlated with maximum speed in HF and FS, but no correlations were found with running route variables. These results suggest that reducing the rate of deceleration and increasing the maximum speed in the FS section will shorten the BR time to the second base, which should be achieved by changing the route in the HF section.

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This study attempted to develop a goal-type ball game as a teaching material for first-grade junior high school students and to verify its effectiveness. The game was designed to help students acquire tactical knowledge by considering the connection between ball sports and ball games. Goal-type games in the courses of study include basketball, handball, and soccer, the latter being chosen for material development in this study. To reduce the difficulty of ball manipulation specific to soccer, we reduced the number of participants in the game, devised rules such as the size of the court, and replaced the ball with a disc-shaped object. Additionally, 4 types of task games – 2 passing games and 2 out-number games – were used in the unit designed to help learners recognize tactical issues and develop solutions to them. To verify the effectiveness of the teaching materials, 3 surveys were conducted: one evaluated the validity of the unit content based on diagnostic and summative class evaluations, another tested the level of tactical understanding, and the third measured motor skills through video analysis using the Game Performance Assessment Instrument. The results revealed the following: (1) Tactical tasks can be clarified, and the effectiveness of task games can be enhanced by adapting teaching tools and rules, allowing for efficient acquisition of tactical knowledge in a limited number of hours. (2) At junior high school level, teaching that supports the parallel acquisition of motor skills and tactical knowledge, leading to situational judgment, may enhance the development of the specific motor skills required to address tactical problems through action. (3) To improve cognitive skills, such as tactical knowledge acquisition and situational judgment, along with motor skills – both of which contribute to competitive actions during a game – teaching materials for goal-type ball games should focus on content related to both tactics and motor skills. These findings will be valuable for the development of teaching tools and rules for soccer lessons aimed at first-year junior high school students.

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　This study aimed to examine the submaximal aerobic capacity of elite sitting para-athletes with and without spinal cord injury. The participants were Japanese elite para-athletes, including 6 badminton players, 7 wheelchair tennis players, and 11 alpine ski players (age: 30 (16–46) yrs, body height or arm span: 169.1 (141.9–185.1) cm, weight: 56.2 (37.3–83.3) kg). The participants were divided into two groups: those with spinal cord injuries (SCI, n = 12) and those without (OPA, n = 12). Body mass, lean body mass, and body fat percentage were measured using an air displacement plethysmograph (BODPOD). The participants performed an incremental arm cranking test until their blood lactate concentration exceeded 4 mmol/L. The test protocol for blood lactate concentration was determined based on the participants' events and sex. We evaluated the workload and heart rate at the Lactate Threshold (LT) and the Onset of Blood Lactate Accumulation (OBLA) during the incremental arm cranking test. There were no significant differences between SCI vs. OPA in the workload 52.2 (17.0–70.0) W vs. 54.0 (16.0–82.0) W at LT, and 82.5 (39.6–108.0) W vs. 78.4 (36.0–124.6) W at OBLA and heart rate 119.5 (104.0–138.0) bpm vs. 120.4 (91.0–139.5) bpm at LT, and 149.2 (131.0–165.4) bpm vs. 150.5 (127.0–170.0) bpm at OBLA. The present findings indicate that, in terms of workload and heart rate at LT and OBLA, elite sitting para-athletes with spinal cord injuries have aerobic capacities similar to those of athletes without spinal cord injuries.

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The present study was conducted to investigate the factors that led a physical education teacher (Mr. A) to adopt an interactive and collaborative approach, which was not common at a time when special education was the mainstream for children with disabilities. Adopting an autobiographical approach focusing on his life history during the period of teacher training at university and when he was assigned to a public elementary school, the KJ method and SCAT were used to analyze interviews and records of articles and other documents written by Mr. A. The results revealed the following.
Mr. A’s cross-cultural experience of studying abroad under the guidance and recommendation of his undergraduate thesis advisor was a factor in shaping his identity as a teacher involved in the education of children with disabilities at an elementary school upon graduation.
After being assigned to an elementary school, he initially conducted research on interactive physical education as a special class teacher. However, after being transferred to a school in a remote area, he began to conduct research on interactive physical education as a strategy for utilizing his expertise as a regular classroom teacher. His consistent practice of interactive and collaborative learning in physical education and the presentation of his research stemmed directly from his identity as a teacher involved in the education of elementary children with disabilities, which had formed at the time of his graduation.
Mr. A’s self-belief in the type of teacher he would be during the teacher training stage was an important factor influencing his practice and research into an interactive and collaborative approach to physical education after beginning his teaching career.
As a future issue, it will be necessary to clarify how Mr. A’s self-belief in his identity as a physical education teacher influenced his approach to interactive and collaborative learning in the second and third phases of his career.

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The purpose of this study was to identify the learning possibility of first-year high school students to learn striking and fielding tactics in game classes, based on a case study of students’ prior experiences.
The study subjects were 46 students who elected to participate in striking and fielding game classes based on Teaching Games for Understanding. The comprehension of the tactics taught in the unit and the students’ learning possibility were evaluated using an assessed tactical knowledge test conducted 3 times (at the first, tenth and thirteenth hours of the unit). The results were as follows.
1) Experienced students generally understood the tactics set in this study from the beginning of the unit. In addition, their understanding was maintained throughout the unit.
2) Inexperienced students showed limited understanding of “decisions regarding defensive role actions” and “decisions regarding base running” at the beginning of the unit.
3) More than 70% of the inexperienced students were able to understand tactics related to “backing up the catcher” and “base covering” among defensive role actions by the end of the 9-hour stage. On the other hand, “relaying” and “backing up the base cover” remained challenging for inexperienced students even at the end of the 13-hour stage. This was considered to be due to difficulty in guaranteeing learning opportunities during the game, so that learning throughout the game did not progress effectively.
4) More than 70% of the inexperienced students were able to understand tactics related to base running by the end of the 13-hour stage, suggesting the effectiveness of ensuring opportunities for participation in the game and time for reflection.
These results suggest that some tactics were difficult for inexperienced students to understand at the beginning of the unit. However, it was possible to learn those tactics by implementing modified game rules and teaching materials according to their level of understanding based on Teaching Games for Understanding, using questions related to tactical issues, and by guaranteeing intentional learning opportunities and time for reflection.

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This study aimed to investigate the factors related to reduction of short-track speed-skating lap time by examining the relationships between lap time, skating trajectory, skating speed, average section speed, and excess distance in a curved section during maximum effort. The study included 8 male skaters (age, 21 ± 5 yr, height, 1.67 ± 0.05 m, weight, 63.9 ± 4.7 kg), who skated for 3 laps with maximum effort. The curve section was defined as C1 for the first half up to the midpoint of the curve and C2 for the second half after the midpoint. The time taken in the first half of the second lap, skating trajectory, skating speed, change of speed, section average speed, and excess distance covered in the curved section were calculated. The skating speed was expressed as 100% for the entire curved section. The following results were obtained:
1) All subjects moved from the outside to the inside of the course in C1 and from the inside to the outside in C2.
2) Significantly negative relationships were observed between the half lap time and section average speed as well as skating speed at the starts and ends of the sections in C1 and C2 (p<0.05). Furthermore, significantly positive relationships were observed between the section average speed and the starts of the sections in C1 and C2 (p<0.05).
3) No significant relationships were found between the section average speed and excess distance in C1 and C2.
4) The skating speeds at 50% and 100% were significantly lower than that at 0% (p<0.05). The section average speed in C2 was lower than that in C1 (p<0.05).M
5) In C1, some skaters achieved a higher section average speed with a shorter excess distance, while others had a lower section average speed with a greater excess distance.
These results suggest that, in order to shorten the half lap time, it is important to enter C1 with a higher skating speed and maintain this higher speed at the end of the C2, rather than reduce the excess distance in C1.

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The aim of the present study was to examine the availability of IPmax (maximal intermittent power) determined using a new IPmax test as an intensity index for intermittent sprint training. Eight male track and field athletes performed the IPmax test, a submaximal intensity incremental test, a VO₂max test, and 2 intermittent sprint training protocols (IST1 and IST2). The IPmax test involved repeated 30-s sprints with 2-min rest intervals, continuing until exhaustion with gradually increasing intensity at each stage. The IPmax derived from the IPmax test was used as the intensity index for the IST1 and the IST2. In the IST1, athletes performed 30-s sprints at 105 %IPmax with 2-min rest intervals until exhaustion. The IST2 consisted of 40-s sprints at 95 %IPmax with 4-min rest intervals until exhaustion. The number of repetitions completed in each IST was recorded. The coefficients of variation for the number of repetitions in each IST were 15.3% and 9.1%, respectively, the 9.1% value being significantly smaller in comparison to previous studies (F = 5.3, p < 0.05). The relative intensity of IPmax in the IPmax test was 179 ± 11 %VO₂max, indicating a high intensity level, and was significantly correlated with aerobic capacity (vs. VO₂max, r = 0.77, p < 0.01). Based on these results, we conclude that the IPmax obtained in this study represents a high intensity and has a significant relationship with aerobic capacity, suggesting that it is an intensity index that accounts for both anaerobic and aerobic capacities. Furthermore, the use of %IPmax allows for approximate regulation of the exhaustion point during intermittent sprint training, suggesting its availability as an intensity index for such exercises.

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　The purpose of this study was to examine the relationship between behavioral tendencies among female college athletes (n=639) in senior-junior relationships within athletic clubs and assumed competence arising from undervaluing others. The survey inquired about basic attributes (age, sport, years of experience, highest achievements), and implemented the senior-junior relationship scale in university athletic clubs, the assumedcompetence scale, and the self-esteem scale. Participants also reported the number of friends they currently had and their satisfaction with those friendships. The results of the analysis revealed no differences in ‘dominance and subordination’ among behavioral tendencies related to senior-junior relationships based on differences in sport type or performance level. However, tendencies for ‘fellowship,’ ‘leadership and followership,’ and ‘partnership’ were stronger among those involved in team sports, with no differences based on performance level. Athletes with high assumed competence, characterized by undervaluing others, had fewer significant friends and lower satisfaction with their friendships. Furthermore, these athletes showed weaker tendencies in the 3 behavioral aspects, except for ‘dominance and subordination’, indicating some deficiency in building and maintaining friendly and cooperative relationships between seniors and juniors. In summary, the present results indicate that behavioral tendencies related to senior-junior relationships among female college athletes vary according to the nature of the sport and the level of their assumed competence.

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　The purpose of the study was to determine the factors influencing the performance of college athletes by investigating when they began their athletic careers, when they felt their own performance improved the most, and their other experiences in sport.
　The subjects were 690 college athletes (364 males and 326 females) who had played sports from childhood until their college years. The survey was conducted from May to July 2023 in the form of a web questionnaire using Google Forms. The results show that many of the college athletes had begun competing by elementary school and realized their own peak performance during high school. Many of them considered their start timing as “appropriate” and recognized the importance of starting earlier in their athletic development. Three factors were shown to have an important influence on their competitive performance: “coaches”, “teammates/rivals”, and “training time/amount”. These factors were shown to have a significant impact on both positive and negative aspects. These results provide valuable knowledge about the factors that influence the competitive performance of collegiate athletes.

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The present study attempted to clarify the translation of language tasks into movement in improvisational expression. A survey of previous research suggested that there might be differences in the ease of translation between language tasks, and that it might be possible to identify factors that facilitate easier translation. We adopted an experimental approach in which language tasks were translated into movement in order to clarify whether or not the participants were actually able to translate, the time required for the participants to begin movement after presentation of the language task (thinking time), and the time taken by the participants to complete movement (moving time) after initiating it. The study participants were 33 university students nonspecializing in dance. The language tasks were limited to 28 related to “natural phenomena”, and a total of 924 trials were conducted. The participants were able to translate 853 of the trials, indicating that a high proportion of them (92%) were able to quickly grasp the characteristics of the language tasks and translate them into movement. Next, it was suggested that the participants recalled memories related to the language task and imagined them upon presentation of the task, and that during the translation, the characteristics of the imagined tasks were perceived by the body as physical sensations. Finally, 3 patterns of translation into movement were identified. These patterns suggested that individuals who spent less time thinking found translation easier, whereas those who spent more time thinking found this harder. It was clearly evident that when thinking time was short, moving time also tended to be short, whereas a longer thinking time was associated with a longer moving time. In order from the shortest time, these trends may be attributed to 1) to perceive the movement characteristics of language tasks as the simplest, most dynamic lines, 2) to transform ideas into the human situation in response to language tasks, and 3) to metaphorically interpret the characteristics of language tasks through embodied experiences.

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The striking action in kendo must be performed in such a way that the opponent does not detect the strike, and requires a ballistic muscular exertion without any recoil motion. Recently, the difference between a countermovement jump (CMJ) and a squat jump (SJ) (CMJSJDiff) has been attracting attention as a measure of jumping ability; a smaller CMJSJDiff indicates a greater ability to quickly take up muscle-tendon relaxation, thus facilitating a more rapid jump, which may be related to kendo competition level. The purpose of this study was to examine the difference between CMJ and SJ in kendo players, and its relationship to competitive level. Twentyfive male kendo players from universities participating in national tournaments participated, and were separated into regular and non-regular groups. All tests were performed on the same day, with players performing 2 CMJ and SJ on a mat-switch. Performance index was also calculated as the CMJ to SJ difference. The major study finding was that no difference was evident in the CMJ, whereas significant differences were seen in the SJ and in the CMJSJDiff between the regular and non-regular groups. These results suggest that jumping ability in kendo players is associated with competition level, especially ballistic jumping ability such as the SJ, in comparison to plyometric jumping ability with recoil movements such as the CMJ.

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