The research aims to lift the accuracy of table tennis trajectory prediction through advanced computer vision and deep learning techniques to achieve real-time and accurate table tennis ball position and motion trajectory tracking. The study concentrates on the innovative application of a micro-miniature fourth-generation real-time target detection algorithm with a gated loop unit to table tennis ball motion analysis by combining physical models and deep learning methods. The results show that in the comparison experiments, the improved micro-miniature fourth-generation real-time target detection algorithm outperforms the traditional target detection algorithm, with the loss value decreasing to 1.54. Its average accuracy in multi-target recognition is dramatically increased to 86.74%, which is 22.36% higher than the original model, and the ping-pong ball recognition experiments show that it has an excellent accuracy in various lighting conditions, especially in low light, with an average accuracy of 89.12%. Meanwhile, the improved model achieves a processing efficiency of 85 frames/s. In addition, compared with the traditional trajectory prediction model, the constructed model performs the best in table tennis ball trajectory prediction, with errors of 4.5 mm, 25.3 mm, and 35.58 mm. The results show that the research trajectory prediction model achieves significant results in accurately tracking table tennis ball positions and trajectories. It not only has practical application value for table tennis training and competition strategies, but also provides a useful reference for the similar techniques application in other sports.

Competition in sports, unlike cooperation in everyday life, does not involve a single solution because individuals aim to behave unpredictably, thereby preventing others from predicting their actions. This study determined how individuals in court-based sports attempted to control others\' unpredictable behaviors, addressing the gap in previous studies regarding the lack of clarity around strategies employed by individuals in competitive situations. We achieved this by applying a switching hybrid dynamics model, considering external inputs to analyze individual behaviors. Consequently, the study indicates that skilled individuals, in contrast to intermediate players, exhibit greater consistency in their behaviors. These skilled individuals lead others to anticipate their consistency and subsequently employ strategies to disrupt these expectations. This strategy exploits the principles of active human inference, implying that competition involves cooperation. This was revealed by an analysis of both human decision-making and behavior in actual matches as discrete and continuous dynamical systems. This interpersonal strategy could assist policymakers in the field of everyday life to enhance competitiveness. This strategy enables policymakers to adopt new policies that promote cooperation with competitors, ultimately increasing competitiveness in various aspects of our daily lives.

This article demonstrates the integration of sensor fusion for pose estimation and data collection in tennis balls, aiming to create a smaller, less intrusive form factor for use in progressive learning during tennis practice. The study outlines the design and implementation of the Bosch BNO055 smart sensor, which features built-in managed sensor fusion capabilities. The article also discusses deriving additional data using various mathematical and simulation methods to present relevant orientation information from the sensor in Unity. Embedded within a Vermont practice foam tennis ball, the final prototype product communicates with Unity on a laptop via Bluetooth. The Unity interface effectively visualizes the ball\'s rotation, the resultant acceleration direction, rotations per minute (RPM), and the orientation relative to gravity. The system successfully demonstrates accurate RPM measurement, provides real-time visualization of ball spin and offers a pathway for innovative applications in tennis training technology.

Tennis is an individual sport characterised by high-intensity action, including sprints and changes of direction (COD). However, there is a gap in the knowledge of limb asymmetries in adolescent tennis players and their association with performance. The aim of this study was to investigate the relationship between asymmetry in vertical and horizontal jump tests (CMJ and HJ) and COD with lower limb performance variables in adolescent tennis players. Forty-five adolescent tennis players (age: 13.81 ± 1.08 years; height: 167.64 ± 9.9 cm; body mass: 57.48 ± 10.94 kg; body mass index: 20.27 ± 2.18 kg/m2) performed the CMJ test (unilateral and bilateral), horizontal jumps (unilateral and bilateral), 25 m sprint, and 180° COD test. The single-leg countermovement jump showed the greatest asymmetries among the different tests (6.62 ± 9.35%). Notable negative relationships were found between CMJ asymmetry and COD asymmetry with unilateral horizontal jump variables (r = -0.30 to -0.53). In addition, CMJ asymmetry showed notable relationships with CMJR (r = 0.49) and COD180R (r = 0.29), whereas COD asymmetry showed a notable relationship with COD180L (r = 0.40). On the other hand, HJ asymmetry showed no notable relationships with any variable. The main findings of this study indicate that greater imbalances in the CMJ and COD tests are associated with a reduced capacity to perform unilateral horizontal jumps. These results suggest the incorporation of training protocols to reduce interlimb asymmetries in growing athletes to improve their performance. This practical application is important for coaches and physical trainers who aim to improve the physical performance of adolescent tennis players. Greater asymmetry results in a reduced ability to produce unilateral horizontal force.

Tennis coaches display significant influence, catalyzing changes in athlete performance, motivation, and overall well-being. Research on coaches\' motivations and their impact on coaching style, work, and well-being is limited, especially in individual sports like tennis. Based on self-determination (SDT) and achievement goal (AGT) theories, the aim of the present study was to examine the relationships of coaches\' self-determined motivation (intrinsic, extrinsic, and amotivation), basic psychological needs satisfaction (autonomy, relatedness, and competence), and achievement goals (self-improvement-SI, self-enhancement-SE, self-transcendence-ST) with their coach-created empowering-disempowering motivational climate, work engagement, and well-being (subjective vitality). Participants were 106 tennis coaches from Greece (66 males and 40 females), with an average age of 41.30 ± 12.54 years and coaching experience ranging from six months to 40 years. Data was collected through online questionnaires. Correlation analysis revealed that intrinsic and extrinsic motivation, satisfaction of the three basic psychological needs, and achievement goals were found to be positively related to an empowering climate, work engagement, and subjective vitality. Coaches\' amotivation was positively related to a disempowering climate. Multiple regression analyses showed that autonomy and ST achievement goals significantly predicted tennis coaches\' empowering motivational climate, while none of the independent variables were significant predictors of the disempowering motivational climate. Additionally, intrinsic motivation and ST goal significantly predicted tennis coaches\' work engagement, while autonomy and ST goal significantly predicted their subjective vitality. It is advisable for forthcoming coach education initiatives to consider these findings as an additional justification for tennis coaches to incorporate multiple perspectives into their coaching methodologies.

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It is known that different types of music used during sports performance has different psycho-physiological effects. In this context, this study aimed to reveal the effect of different types of music on ITN test performance in tennis players. A total of 35 recreational tennis players voluntarily participated in the study. In the research, the ITN test performance of tennis players was measured in three different conditions with 48-hour intervals, these being without music, with motivational music, and with sedative music. The Freidman test was used in the analysis of the data that did not show a normal distribution, and the Repeated Measures ANOVA test was used in the analysis of the data that showed a normal distribution. According to the main findings of the study, it was determined that motivational music increased the ITN test performance of tennis players, while sedative music decreased their ITN test performance (p< .05). Additionally, it was determined that motivational music increased the groundstroke depth scores of tennis players, while sedative music decreased groundstroke depth scores (p< .05). In addition to this, it was determined that volley depth, groundstroke accuracy, and serve scores increased through motivational music (p< .05), whereas sedative music had no effect (p> .05). As a result, it was determined that the ITN test performances of tennis players can be increased through the psycho-physiological effect of motivational music. It can therefore be concluded that the use of motivational music during training and matches (between sets and/or time breaks) of tennis players can increase their shooting performance.

Sprint interval training (SIT) is a potent exercise strategy to enhance athletes\' anaerobic capacity in a time-efficient manner. This study aimed to investigate the impact of low-volume, court-based SIT on the anaerobic capacity and sport-specific performance in competitive tennis players. Twenty-four competitive collegiate tennis players were randomly assigned to either the SIT group (n = 12; three sessions per week of court-based repeated-sprint training) or the traditional endurance training (ET) group (n = 12; three sessions per week of 45-min continuous treadmill running, n = 12) for a 6-weeks intervention. Baseline and post-intervention assessments included the Wingate Anaerobic Test, elimination rate of blood lactate (BLAer), tennis-specific repeated sprint ability (RSA), and the Yo-Yo Intermittent Recovery Test Level 2 (YoYo-IR2). The results showed that SIT group demonstrated significant improvements in peak and average power during the Wingate test (p = 0.07; p < 0.001), along with a notable increase in YoYo-IR2 performance (7.8% increase, p = 0.04). Significant decreases were observed in both mean (5.1% decrease, p = 0.02) and sum RSA time (5.2% decrease, p = 0.02) in the tennis-specific RSA assessments. Additionally, the SIT group showed significantly higher effective training time and TRIMP in the 90-100% HRmax zone compared to the ET group (p < 0.01). This study underscores the potential benefits of low-volume, court-based SIT in enhancing anaerobic capacity and sport-specific performance in competitive tennis players, in comparison to traditional ET.

The research analyzed the effect of weekly training plans, physical training frequency, AI-powered coaching systems, virtual reality (VR) training environments, wearable sensors on developing technical tennis skills, with and personalized learning as a mediator. It adopted a quantitative survey method, using primary data from 374 young tennis players. The model fitness was evaluated using confirmatory factor analysis (CFA), while the hypotheses were evaluated using structural equation modeling (SEM). The model fitness was confirmed through CFA, demonstrating high fit indices: CFI = 0.924, TLI = 0.913, IFI = 0.924, RMSEA = 0.057, and SRMR = 0.041, indicating a robust model fit. Hypotheses testing revealed that physical training frequency (β = 0.198, p = 0.000), AI-powered coaching systems (β = 0.349, p = 0.000), virtual reality training environments (β = 0.476, p = 0.000), and wearable sensors (β = 0.171, p = 0.000) significantly influenced technical skills acquisition. In contrast, the weekly training plan (β = 0.024, p = 0.834) and personalized learning (β = -0.045, p = 0.81) did not have a significant effect. Mediation analysis revealed that personalized learning was not a significant mediator between training methods/technologies and acquiring technical abilities. The results revealed that physical training frequency, AI-powered coaching systems, virtual reality training environments, and wearable sensors significantly influenced technical skills acquisition. However, personalized learning did not have a significant mediation effect. The study recommended that young tennis players\' organizations and stakeholders consider investing in emerging technologies and training methods. Effective training should be given to coaches on effectively integrating emerging technologies into coaching regimens and practices.

UNASSIGNED: The aim of this systematic review is to provide an evidence-based synthesis of the literature on the topic of technical and tactical competencies of tennis players and to answer the following research questions: (1) What is the state of the art of research on technical and tactical competencies (i.e., skills and knowledge) and tennis; (2) What are the most important topics related to technical and tactical competencies in tennis players.
UNASSIGNED: Electronic searches were conducted in Web of Science, PubMED and SPORTDiscus (August to September 2023). This systematic review was conducted in accordance with PRISMA guidelines. To reduce risk, all published literature was searched and primary studies were included. The search terms included skills or competencies, match or play, player and tennis and excluded studies on non-competitive tennis players-notation analysis, AI method, systematic review and validation of tools.
UNASSIGNED: Of the 390 publications found in these searches, 13 articles were considered relevant and included in this study. They were divided into three categories: (1) technical-tactical skills, (2) match situations and (3) match performance. There was clear evidence that there is a test instrument for analyzing tactical-technical skills that has sufficient reliability and validity and is of practical value to tennis coaches. The development of tactical-technical skills is influenced by method (variability between/within skills), conditions (court size, ball type) and areas of development (situational awareness, anticipation, decision making). There are differences in match and stroke performance between different quality groups (professionals, juniors), which can also be influenced by mental strength. For a comprehensive study of tennis players\' abilities, the use of modern technologies is possible and necessary in the future. Future research should focus on the creation of competency models for the playing level of tennis players, which could include at least three key elements: (1) key competencies, (2) description of standards, (3) evidence.