This study aimed to clarify the relationships between athletic performance and trunk control on the sudden unanticipated load in adolescent football players. Eighteen adolescent football players performed trunk-control tests, namely, front- and back-bridge tests, and field tests, namely, sprint, arrowhead agility, countermovement jump, and standing five-step jump tests. For the trunk-control tests, the angular velocity of the trunk was measured using an inertial sensor. The relationships between the field test and each parameter of the trunk-control tests were analyzed using the Pearson correlation coefficients. Sprint time was significantly and positively correlated with the angular velocity of the x-axis in the front-bridge (r=0.743-0.701, p<0.01) and back-bridge (r=0.612-0.491, p<0.05) tests. The arrowhead agility test was correlated with the angular velocity of the x-axis (r=0.543, p=0.020) and y-axis (r=−0.533, p=0.023) in the front-bridge test, and that of the x-axis (r=0.546, p=0.019) in the back-bridge test. Since the x- and y-axes of the angular velocity indicate trunk rotation in both tests and trunk extension in front-bridge test, respectively, these findings indicated that the control of trunk rotation and extension is important for the optimal sprinting and change-of-direction performance.

This study examined the psychometric properties of career engagement among professional female football players in Japan. First, the Japanese version of the Career Engagement Scale (J-CES) was developed using the forward-back translation methods based on the original version. This study allowed the measurement of career engagement in Japanese. Second, one hundred and forty-six professional female football players responded to an online survey of the J-CES. The study examined the reliability and validity of the scale using Cronbach’s alpha coefficient, McDonald’s omega coefficient, and confirmatory factor analysis. The classical test theory analyses indicated that the J-CES had a high internal consistency (α=0.88, ω=0.85) and was not adequately validated. Third, the factor structure of J-CES was re-examined using the methods of determining the number of factors. As a result, one- and two-factor structures were proposed. Fourth, item analysis using a unidimensional graded response model was conducted to obtain findings on more valid items for the J-CES of the one-factor structure. The item response theory analyses revealed that the J-CES had good discrimination for Items 1–4 (a>1.35). Items 1–4 are statements concerning future career-related abstract behaviors. Furthermore, we also confirmed that the simple structure with the two-factor model could be obtained using exploratory factor analysis (principal factor method with promax rotation). J-CES may be useful for investigating career engagement in light of cultural, social, and athletic differences in the future.

Although the Japan Sports Agency has actively promoted sport tourism, few studies have directly compared the impacts of sport tourism on life satisfaction across non-sport tourists, participation-based sport tourists, and spectator-based sport tourists. Therefore, this study aimed to investigate the effects of sport tourism on life satisfaction and compare its impact among non-sport tourists, participation-based sport tourists, and spectator-based sport tourists. Utilizing a two-wave prospective longitudinal design, usable data were collected from 419 tourists through online surveys administered before and after travel, categorizing participants based on their engagement in sport activities at destinations. Our sample consisted of 331 non-sport tourists, 67 participation-based sport tourists, and 21 spectator-based sport tourists. Our analysis revealed significant increases in life satisfaction across all groups. The impact was comparable across the groups, indicating the importance of overall, rather than specific, tourism experiences on life satisfaction. However, the different effect sizes suggest that the casual nature of spectator-based sport tourism might provide greater benefits to life satisfaction than the more demanding participation-based sport tourism. This study confirmed the positive impact of sport tourism on life satisfaction among Japanese adults, in line with the Japan Sports Agency’s initiatives aimed at enhancing well-being through sports, highlighting the need for further research to support the ongoing development of sport tourism in Japan.

Following the revision of the five-player substitution rule for soccer in 2022, the number of substitutes and their playing time increased, and tactical flexibility was created by replacing several players early in the game. Therefore, in modern soccer, having a squad depth that includes players who are used as the starting players (regular players) and reserve players and substitutes (non-regular players) is important. However, maintaining non-regular players’ motivation is difficult. This study aimed to clarify the psychological process by which non-regular soccer players overcome the difficulty of not becoming a regular player. Semi-structured interviews were conducted to determine how these individuals perceived and overcame this difficulty. The results were analyzed using the Modified Grounded Theory Approach, which generated six categories containing 26 concepts. Non-regular players combine different strategies to overcome their negative feelings regarding their present situation of being unable to attend games. This study revealed the transformative process involved in overcoming these negative feelings. In this process, players overcome the difficulty of being unable to attend games by combining various coping strategies, while experiencing negative feelings regarding their present situation. Thus, this study suggests that players in similar situations may be able to appropriately utilize coping strategies and confront difficulties by following this process.

This study compared the effects of carbohydrate (CHO) and glucogenic amino acid (MIX) supplementation to those of isocaloric CHO supplementation on self-paced intermittent running performance. In a randomized crossover design, eight males completed two experimental trials (MIX or CHO) comprising 45 min of self-paced intermittent running on a non-motorized treadmill. Intermittent running consisted of a 15-s walk at 10% effort, 30-s jog at 45% effort, 25-s run at 75% effort, 16-s rest, and 4-s sprint at 100% effort; cycles were repeated over 45 min. Participants consumed a commercially available jelly drink containing either MIX (0.13 g‧kg⁻¹ alanine, 0.01 g‧kg⁻¹ proline, and 1.11 g‧kg⁻¹ CHO) or CHO (1.25 g‧kg⁻¹) 10 min before commencing intermittent running. The distance covered in sprints during the first 15 min was significantly higher in MIX than in CHO (p=0.043, d=0.32). The total distance covered were comparable between the trials (p>0.05). The blood lactate concentration at the end of the first 15 min was significantly lower in MIX than in CHO (p=0.008, d=0.78). Throughout the exercise, the blood glucose concentration was significantly lower in MIX than in CHO (p=0.049, d=1.16). There were no significant differences in heart rate, dehydration rate, or rating of perceived exertion during exercise between the trials (p>0.05). In conclusion, alanine and proline combined with CHO supplementation increased sprint performance in the initial part of self-paced intermittent running compared with isocaloric CHO supplementation. However, this supplementation did not increase the total distance covered during the self-paced intermittent running.

This study examines the concept of taiken (lived experience) and its implications for physical education. The analysis explores the multifaceted interpretations of taiken and traces its development through the interconnected stages of experience, expression, and understanding. The primary examination revealed the following:

　1.　Diverse interpretations of taiken exist. In Germany, lived experience (Erlebnis) is often understood as the exteriorization of expression and the pursuit of objective understanding. In Japan, interpretations vary, with some viewing taiken negatively as a closed experience, while others see it positively as the merging of self and world.

　2.　Taiken emerges prior to conscious awareness and then transitions through subsequent stages. During the stage of expression, taiken takes shape and becomes more defined, while the stage of understanding involves making sense of the experience and potentially forming objective knowledge.

　3.　Taiken is closely intertwined with bodily perception. The study found that taiken begins with conformity to the “body schema”—an individual’s internal sense of their body in space—and manifests as unconscious bodily motion. At the stage of expression, taiken related to bodily motion becomes understood more objectively.

Based on these findings, the educational significance of taiken in physical education is reconsidered, leading to the following conclusions:

　1.　Taiken represents a form of perception that precedes conscious thought, allowing individuals to experience the world without the constraints of utilitarian goals.

　2.　Taiken manifests in bodily movement, which can be understood both objectively and subjectively.

　3.　Taiken can lead to the development of objective understanding as individuals move from subjective perception to more formalized knowledge.

　4.　These diverse interpretations highlight the need for physical education to carefully consider the specific aspects of taiken it seeks to cultivate and how those aspects contribute to meaningful learning experiences, fostering holistic learning and personal growth.