Effects of Mental Visualization on Plyometric Performance and Self-Confidence of Football Players.

Plyometric training in football is essential for enhancing athletic performance, as it allows for increasing strength and speed in gameplay. Meanwhile, mental visualization improves players' technical play and motor performance during both training and competitions, thereby contributing to an overall sports performance enhancement. Collectively, physical and technical training is thought to boost athletes' confidence in facing competitive demands. Our aim in the present study was to analyze the effectiveness of mental visualization during a plyometric training program for improving strength speed, and competitive self-confidence in young adult football (soccer) players. Our sample consisted of 40 male players aged between 19 and 25 years (M = 20.82; SD = 1.26). We used a quasi-experimental design with a control group and pretest/posttest measurements. The experimental group participated in an 8-week plyometric training program that incorporated visualization tasks, while the control group underwent the same program but without visualization exercises. We found significant improvements for the experimental group on vertical jump (p = .047) and speed (50-m sprints) (p < .034) tests, as well as in their perceived competitive self-confidence (p < .017). These findings suggest that combining plyometric exercises with visualization tasks may contribute to better motor learning, increased lower limb muscle speed and strength, and self-confidence to face competition.

Engagement in Transformational Leadership by Teachers Influences the Levels of Self-Esteem, Motor Self-Efficacy, Enjoyment, and Intention to Be Active in Physical Education Students.

In the school context, the teacher-student interaction style plays a pivotal role in ensuring optimal adolescent functioning. Over recent years, the significance of transformational teacher leadership in fostering student engagement and positive development has been underscored. This study aimed to examine the correlations between transformational leadership and adolescent self-esteem, motor self-efficacy, enjoyment in physical education classes, and intention for future physical activity. This research used an associative and predictive strategy. A total of 429 adolescents from Málaga, aged between 14 and 16 years (M = 14.97; SD = 0.85), participated in this research, which employed an associative, comparative, and predictive approach. The Transformational Teaching Questionnaire (TTQ), Motor Self-Efficacy Scale (MSES), Intrinsic Satisfaction in Sport Instrument (SSI-EF), and Intention of Being Physically Active Scale (MIFA) were utilized for variable assessment. Correlation, Multiple Regression, and cluster analyses revealed statistically significant correlations between transformational leadership and self-esteem, motor self-efficacy, enjoyment, and future activity intention. Specifically, it was revealed that motivational inspiration predicts self-esteem, motor self-efficacy, enjoyment, and intention for physical activity, whereas intellectual stimulation predicts motor self-efficacy, enjoyment, and intention for physical activity. Notably, the transformational leadership factors of intellectual stimulation and motivational inspiration were observed to predict scores across other variables, particularly enjoyment in physical education classes, both overall and by gender. These findings suggest that transformational leadership in physical education classes can significantly enhance student experiences, thereby promoting adherence to physical activity and healthy lifestyles among adolescents.

Effects of combined training in individual with Intellectual and Developmental Disabilities: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE OF THE ARTICLE: This study aims to evaluate the literature, peer-reviewed clinical trials investigating the effects of combined exercise interventions on individuals with Intellectual and Developmental Disabilities. MATERIALS AND METHODS: Various databases, using various descriptors and Boolean operators were utilized. RESULTS: Eight studies meet the eligibility criteria. Regarding the anthropometric measures/body composition variable, the meta-analysis revealed that combined physical exercise did not have a significant effect (standard mean difference (SMD) = -0.16; 95% CI, -0.34 to 0.03; Z = 1.68; p = 0.09). For the lipid profile variable, the combined exercise interventions did not show a significant effect (SMD = -0.07; 95% CI, -0.43 to 0.29; Z = 0.38; p = 0.71). Combined exercise training had a significant effect on increasing functional capacity (SMD = 0.28; 95% CI, 0.01 to 0.54; Z = 2.03; p = 0.04), cardiorespiratory function (SMD = 0.80; 95% CI, 0.34 to 1.26; Z = 3.41; p ≤ 0.001), and strength (SMD = 0.77; 95% CI, 0.45 to 1.08; Z = 4.78; p ≤ 0.001). CONCLUSIONS: Participants from the intervention group that took part in combined exercise training showed a higher probability of improving their functional, cardiorespiratory, and strength capacity compared to the control group.

This study synthesises the literature, peer-reviewed clinical trials investigating the effects of combined exercise interventions on individuals with Intellectual and Developmental Disabilities.Participants who performed combined physical exercise were more likely to improve their functional, cardiorespiratory and strength capacity compared to the control group.Professionals (e.g., rehabilitation technician, exercise technician) responsible for planning interventions for people with IDD should consider the results of this study when planning their interventions, particularly regarding the prescription of physical exercise, as well as monitoring training and several important variables that can be enhanced by regular physical exercise.Organisations that provide support to people with IDD (support or social solidarity institutions) should also consider the results of this study, to provide the necessary conditions (materials, spaces or human resources) so that professionals could plan this type of intervention in the most appropriate and adapted way possible for the individual.

Neuropsychological analysis of anxiety and executive control of motor patterns in athletes and non-athletes.

Introduction: Even simple tapping tasks require cognitive processes. Some variants of the Finger Tapping Test (FTT) may reveal cognitive aspects associated with frontal processing, including executive functions such as inhibition, or emotional aspects such as anxiety. A context of particular interest for the application of cognitive-motor-anxiety interactions is sports. Although athletes generally exhibit better anxiety levels, they may experience heightened anxiety before important competitions. The problem lies in determining whether the application of anxiety control techniques can be useful in pre-competition situations, given the lack of quick and easy methods to detect if an athlete is experiencing anxiety at a particular moment. Methods: This exploratory study evaluated anxiety using online versions of questionnaires (ISRA, the Competitive State Anxiety Inventory-2, and STAI) and applied a variant of the FTT to 204 participants, both athletes and non-athletes. The scores were compared and correlated. Results: Athletes exhibited lower general anxiety and greater cognitive resistance to interference (better cognitive inhibition). Non-athletes displayed a particular parameter in the FTT variant that differed from the one obtained by athletes and exhibited higher anxiety levels. In the athletes' group only, anxiety was correlated with a specific parameter of the FTT task. Discussion: Our conclusion is that this parameter holds potential relevance in elite sports performance to detect if an athlete is experiencing anxiety. It could be of particular interest in psychological interventions in sports. Further investigation is warranted to fully explore this potential.

Effects of a Psychological Intervention Program on Competitive Anxiety and Psychological Profile in Young Soccer Players.

Our aim in the present study was to test the efficacy of a 13-week, 19-session psychological intervention program on young soccer players' competitive anxiety and their sport psychological profiles. Participants were 37 players in the under-15 age category, of which 18 players formed the experimental group (M age = 14.67 years, SD = .48) and 19 players formed the control group (Mage = 14.23 years, SD = .42); this was a quasi-experimental design without random assignment to groups. We had all participants complete the Psychological Inventory of Sport Performance (IPED), the Questionnaire of Psychological Characteristics of Sport Performance (CPRD), and the Competition State Anxiety Inventory-2 (CSAI-2) before and after the intervention. Results indicated positive effects for the intervention group (but not the control group) on stress control and motivation dimensions of the CPRD, cognitive anxiety and self-confidence on the CSAI-2, and self-confidence and attentional control on the IPED. These results suggest that psychological training for athletes contributes to their improved psychological skills, providing them tools to better adapt to the competitive environment.

Associations between Fluid Intelligence and Physical Fitness in School Children.

Previous research has highlighted that active lifestyles that contribute to improved physical fitness are positively related to cognitive functioning in children and adolescents. Specifically, the increase in physical condition at school age is considered relevant because it is related to better cognitive ability and greater academic performance. Thus, the aim of this study was to analyze the relationships between explosive strength, speed-agility, and fluid reasoning in schoolchildren. To achieve this objective, an associative, comparative, and predictive design was used in this research. A total of 129 children participated in this study (age: M = 9.48; SD = 0.99). To assess fluid reasoning, the Raven test's Standard Progressive Matrices Subtest and the Wechsler Intelligence Scale for Children (WISC-V) were used. To assess physical fitness, the speed-agility test and the horizontal jump test (ALPHA-fitness battery tests), as well as the ball throw test (2 kg), were used. The results showed that the speed-agility test significantly predicted WISC-V Fluid Reasoning Index scores, and the medicine ball toss test significantly predicted Raven test scores. The results obtained highlight the associations between physical condition at these ages and fluid intelligence. This suggests that promoting active lifestyles that improve physical fitness could have a positive impact on children's cognitive health.

Generalizability Theory in the Evaluation of Psychological Profile in Track and Field.

Generalizability theory (GT) has been used throughout the scientific literature to ensure validity, reliability, and generalizability in different sport contexts. However, there is a small number of studies examining the measurement of psychological profiles in sport from this perspective. Therefore, this study's main goal is the sources of variability and the optimal measurement design estimation for a good assessment of the psychological profile in track and field. The sample consisted of 470 participants (age: Average= 32.1; Standar Desviation = 13.5). The analysis of variance and generalizability component analysis has been performed in order to test the reliability and generalizability of the sample. The profile included the following variables: flow, motivation (from Self-Determination Theory and Achievement Goals), self-confidence, and psychological skills. Results confirm that the sample has a high degree of reliability and generalizability in all the tested models. So, a detailed study on the validity, reliability, and generalizability of samples and measures should be an inherent element in the practice of psychological counseling in sports.

Interpersonal behaviors in sports context: Spanish adaptation and measurement invariance.

Introduction: The interpersonal behavior questionnaire (IBQ) is an instrument that measures support and thwarting interpersonal behaviors based on the self-determination theory (SDT). The aim of this work was to adapt the IBQ to the Spanish spoken in Mexico and to examine its psychometric properties (structural validity, discriminant validity, composite reliability, factorial invariance, and nomological validity) in a sample of athletes. Methods: For this purpose, 472 athletes (average age 17.15 years; SD = 1.47) completed a question booklet. Results and discussion: Confirmatory factor analysis supported the structure of six related factors, three factors of behaviors that support autonomy, competence, and relatedness, and three factors of behaviors that thwarting them. The internal consistency of each factor was also supported, as well as the average variance extracted. However, the discriminant validity between the factors of competence and relatedness in their dimensions of support, on the one hand, and thwarting, on the other, is questioned. Factorial invariance was confirmed across gender (men and women) and sport type (individual and team). Nomological validity is in accordance with theory and empirical literature. More studies of the IBQ in sport are necessary to see if these results are a fortuitous product or if they manifest themselves consistently.

Motivational Orientation, Boredom and Fun in Physical Education: The Mediation Role of Self-Esteem and Motor Self-Efficacy.

Adolescents who enjoy physical education (PE) classes are more likely to be active during out-of-school hours. Similarly, achievement goal theory suggests that task-oriented motivation is associated with higher levels of reported fun during PE classes. In contrast, ego-oriented motivation has been related to boredom in class, but some self-perceptions (e.g., self-esteem or motoric self-efficacy) may modify this relationship and are important for physical activity. Our aim in this paper was to analyze the relationships between motivational orientation and fun and boredom in PE classes by assessing the mediating effects of self-esteem and self-efficacy. We surveyed 478 teenagers between 13 and 18 years of age (M = 14.57; SD = 1.15) with the Task and Ego Orientation in Sport Questionnaire (TEOSQ), the Rosenberg Self-Esteem Scale (RSE), the Motor Self-Efficacy Scale (MSES), and the Intrinsic Satisfaction in Sport Scale (SSI-EF). We used a structural equation model to evaluate relationships between these variables of interest. We found a positive relationship between ego orientation and boredom and between task orientation and fun; and we found a negative relationship between task orientation and boredom in PE classes. Importantly, we observed indirect effects from self-esteem and motoric self-efficacy in the relationships between motivational orientation and boredom and fun in PE. These results highlight the importance of students' motivational orientations in PE classes and illustrate that self-perception of self-esteem and motoric self-efficacy can mediate these relationships.

Analysis of the Sports Psychological Profile, Competitive Anxiety, Self-Confidence and Flow State in Young Football Players.

The objective of this study was to analyse the correlations among the sports psychological profile, competitive anxiety, self-confidence and the flow state of young football players. Additionally, potential distinctions based on age category, competitive level and field position were explored. This study included 328 participants divided into two groups: Group 1, 14-15 year olds, and Group 2, 16-18 year olds (M = 15.85; SD = 1.44). Data were collected by using the Psychological Inventory of Sports Execution (IPED), the Revised Competitive State Anxiety Inventory-2 (CSAI-2R) and the Flow State Scale (FSS). The findings revealed positive associations between the sports psychological profile and self-confidence, as well as with the flow state. Conversely, competitive anxiety demonstrated negative relationships with the sports psychological profile, self-confidence and the state of flow. Moreover, superior scores were observed in the analysed variables for the older age category and higher competitive level, with no notable disparities based on field positions. These results underscore the interplay of psychological factors in the performance of football players and underline distinctions among players according to their category (age and level). This emphasises the importance of scrutinising these variables in athletes to comprehend their profiles and enable targeted interventions aimed at enhancing their psychological resources for competitive scenarios.

The effect of the colour red in 20 years of Olympic taekwondo.

The objectives of this study were (1) to analyse the relationship between the colour of the protectors and the outcome of 895 matches in the six Olympic Games in which taekwondo has been included, and (2) to analyse the effect of confounding factors through the different degrees of asymmetry between contestants. Data were recorded on the colour of each athlete's protectors, the scoring system, the sex of the athlete, the weight category, the round of competition, the winner of the match, the method of victory and the points scored by each athlete. Among the main results, a relationship emerged between male athletes wearing red and winning the match (p = 0.034) under the manual scoring system. There were relationships between female athletes wearing blue and winning the match in the quarterfinal (p = 0.014) and last 16 rounds (p = 0.021) using the manual and electronic scoring systems respectively. In female athletes, relationships emerged between wearing blue and winning the match with small (p = 0.008) and medium (p = 0.047) asymmetry under the manual system and with large (p = 0.036) asymmetry under the electronic system. The electronic system had a positive impact on the fairness of Olympic competition. Red tends to gain in importance as the asymmetry between the two athletes decreases, but not enough to give a competitive advantage. The results for Olympic competition held in the now concluded era of the manual system confirmed the presence of the colour effect as a result of psychological factors attributable to referees and judges.

How Does the Level of Physical Activity Influence Eating Behavior? A Self-Determination Theory Approach.

Physical activity and diet are two predominant determinants of population health status that may influence each other. Physical activity has been identified as a behavior that may lead to a healthier diet and regulates eating behaviors. This research aimed to investigate how the level of physical activity is associated with the motivation related to eating behaviors and, consequently, the eating style individuals have on a daily basis. This was a cross-sectional study in which participants completed an online questionnaire that assessed the following variables: the level of physical activity, the motivation toward eating behavior, and the type of eating behavior. In total, 440 individuals (180 men and 260 women) who regularly exercised in gyms and fitness centers aged between 19 and 64 years (M = 33.84; SD = 10.09) took part in the study. The data were collected following the Declaration of Helsinki and with the approval of the Ethics Committee of the Polytechnic of Leiria. For the statistical analysis, mean and standard deviations were first calculated, as well as bivariate correlations between all the variables of interest. Then, structural equation model analyses were performed considering the levels of physical activity as the independent variable, motivations toward eating behavior as the mediators, and eating styles as the dependent variables. It was concluded that a greater level of physical activity leads to a more self-determined type of eating regulation, which in turn results in less constricted eating behaviors that are influenced by external factors and emotional factors.

Logical Intelligence and Mathematical Competence Are Determined by Physical Fitness in a Sample of School Children.

Previous research has shown positive relationships between fitness level and different cognitive abilities and academic performance. The purpose of this study was to explore the relationships between logical-mathematical intelligence and mathematical competence with physical fitness in a group of pre-adolescents. Sixty-three children (50.79% girls; 49.21% boys) from Castro del Río (Córdoba, Spain), aged between 11 and 12 years (M = 11.44, SD = 0.64), participated in this research. The Superior Logical Intelligence Test (SLIT) and the EVAMAT 1.0-5 battery were used. Physical fitness was evaluated by the horizontal jump test, the 4×10 meter speed-agility test, and the Course Navette test. The analyses showed positive relationships between physical fitness with logical-mathematical intelligence and mathematical competence. Specifically, linear regression analyzes indicated that the 4×10 speed-agility test significantly predicted mathematical competence (R 2 = 0.16; ß = -0.41) and the horizontal jump test significantly predicted logical-mathematical intelligence (R 2 = 0.24; ß = 0.50). These results are in agreement with previous research, highlighting the importance of improving physical fitness from an early age due to its benefits for intellectual and academic development.

Efficacy of Electromyographic Biofeedback in Muscle Recovery after Meniscectomy in Soccer Players.

Electromyographic biofeedback (EMG-BF) is a therapeutic technique that has been used successfully in the rehabilitation of injuries. Although it has been applied to athletes, its use in this field is not very widespread. The objective of this study is to analyze its effectiveness in the recovery of electromyographic activity of the quadriceps after meniscectomy, evaluated through isometric contraction of the vastus lateralis. The sample comprised ten professional footballers in the Spanish League (2nd Division A) who had previously suffered a meniscus injury in their knee and had undergone a meniscectomy. The intervention consisted of EMG-BF treatment lasting between 6 and 10 sessions. The electromyographic signal was recorded using a Thought Technology ProComp Infiniti 8-channel biofeedback unit with a sampling rate of 2048 samples/second. For each session, a within-subject ABA design of 6 or 10 trials per session was used, with three pre- and three post-measures, which determined the gain for each session. The results indicated (1) improvements in all cases, (2) EMG-BF was effective, (3) the working model was statistically significant with an explained variance of between 67% and 75%, and (4) the generalizability analysis showed that the results are reliable and generalizable. The results indicate that EMG-BF is effective in neuromuscular rehabilitation after this type of intervention.

Application of the Polar Coordinate Technique in the Study of Technical-Tactical Scoring Actions in Taekwondo.

The objective of this study was to design, validate and update an observation tool to analyse the technical-tactical actions by which taekwondo players win points. An ad hoc observational tool was developed for subsequent use in HOISAN software by viewing seven finals (14 viewings) in the Rome 2019 Grand Prix, collecting data (1,382 technical/tactical actions) from both winners and losers (women, n = 3; men, n = 4). An observational methodology based on a nomothetic, follow-up and multidimensional (N/F/M) observational design was used. In the statistical analysis, to check the validity of the generalizability analysis, the Category/Observer (C/O) and Observer/Category (O/C) models were employed, and to determine reliability between observations (intra- and interobserver), the Pearson, Spearman, Kendall's tau-b and Cohen's kappa correlation coefficients were applied. One point were awarded for every penalty given against the opponent. Two points were obtained for a circular technique to the trunk protector (in winners) or by scoring a point for a punch plus a penalty against the opponent, three points in melee actions, anticipatory actions with the left side (winners), or after a punch action, and circular technique (losers). Four and five points were only obtained by winners, in a direct attack with the right leg, turning (five points) or simultaneous (four points). The results of this study provide information on the most effective technical-tactical actions in taekwondo for scoring points in a contest.

The Relationship between the Color of Electronic Protectors and the Outcome in Taekwondo Matches: Is There Fairness in National Competitions?

Although research on the effect of color in taekwondo has involved several international competitions, no previous study has investigated the presence of this phenomenon in national-level competitions. The main objective of this study was to analyze the relationship between the color protectors and success in 1155 taekwondo matches of the Italian and Uzbekistan Senior Championships (ITA-SC and UZB-SC) (2019 and 2021). The results showed no relationship between the color protectors and the match outcome, in both ITA-SC and UZB-SC (p = 0.71, V = 0.01; p = 0.61, V = 0.02). Moreover, no relationship emerged between the color protectors and the match outcome in the four editions of the SC. Stratifying analyses by weight category and sex, males showed positive relationships between the color blue/red and winning the match in 3 and 1 of 16 weight categories, respectively. Contrary, females showed positive relationships between the color blue/red and winning the match in 1 and 3 of 16 weight categories, respectively. Analyzing the two national contexts found that, in both the Italian and Uzbek contexts, matches in 2 and 2 of 16 weight categories were won by athletes wearing blue and red protectors, respectively. Significant relationships emerged between the color blue and winning the match with small asymmetry in the men's UZB-SC and between the color red and winning the match with large asymmetry in the female ITA-SC. The implementation of the electronic point recording system for the body and head has had a positive impact on fairness in national taekwondo competitions, did not detect any effect of color related to cultural context, and did not allow for the color red to tip the scales between losing and winning in matches between athletes of similar ability and strength.

Exploring the Relationship between Fibromyalgia-Related Fatigue, Physical Activity, and Quality of Life.

The symptoms of fibromyalgia are varied, including general muscle pain and pain at specific points (also called tender points), excessive fatigue, anxiety, depression, and some psychological problems that can have a negative impact on quality of life. Physical activity is a widely used option by health professionals to alleviate the effects of this syndrome. However, there is no clear information on the possible mediating role of physical activity in the relationship between fibromyalgia-related fatigue and quality of life. Therefore, this study aims to evaluate the relationship between fibromyalgia-related fatigue and quality of life, and to investigate the mediating role of physical activity in patients with this syndrome. METHODS: In a cross-sectional study, 237 Portuguese women aged 28 to 75 years (M = 49.12; SD ± 8.87) and 117 Brazilian women aged 20 to 69 years (M = 46.72; SD ± 8.38) were recruited to participate in this study. These patients completed three valid and reliable questionnaires related to the assessment of fibromyalgia-related fatigue (MDF-Fibro-17), physical activity (IPAQ), and quality of life (SF-36). RESULTS: Both samples had scores above the midpoint for all dimensions of fibromyalgia-related fatigue and scores below the midpoint for quality of life. Physical activity had no mediating effect in either sample, as the total indirect effect was not significant. CONCLUSIONS: Physical activity does not mediate the relationship between fatigue and quality of life. However, the results also show that the fatigue dimensions associated with fibromyalgia had a negative and significant association with physical and mental health indicators in both samples. Thus, patients with FM with higher scores on fatigue-related symptoms might suffer more from physical and mental health, both of which are related to quality of life.

Task and Ego Orientation in Sport Questionnaire (TEOSQ): Psychometric Properties in Its Digital Version.

The Task and Ego Orientation in Sport Questionnaire's (TEOSQ's) psychometric properties have been explored in previous studies but never in its digital version, which facilitates data collection. The objective of this study was to analyze the psychometric properties of the online TEOSQ by MenPas 1.0. The sample was composed of 2320 users (58.4% women; 41.6% men), between 18 and 65 years old (M = 25.27, SD = 7.39). The methods used were Confirmatory Factor Analysis (CFA) and invariance analysis from the original 13-item model. The CFA was corrected for all samples (CFI = 0.92-0.94, TLI = 0.93-0.95, RMSEA = 0.07, SRMR = 0.06; df = 64; Bollen-Stine Bootstrap p = 0.02-0.07): general sample (χ2 = 720.72, χ2/df = 11.26), women (χ2 = 496.85, χ2/df = 7.76), men (χ2 = 321.67, χ2/df = 5.03), individual sports (χ2 = 525.26, χ2/df = 8.21), and team sports (χ2 = 306.01, χ2/df = 4.78). The results also indicate optimal adjustments for invariance: convergent, discriminant and composite reliability validity. The study evidence demonstrates the adequate psychometric properties of the digital version. To conclude, considering the results obtained, the model shows a good psychometric fit for the sample in its online format. The principal limitations were computer failures, as well as that the large part of the sample were users between 20 and 25 years old, so the heterogeneity should be improved. The practical implications of this study could improve the efficacy of data collection in sports motivation using the online TEOSQ.

Data Mining and Polar Coordinates in the Analysis by Gender of Finishing Behaviors in Professional Basketball Pick and Roll.

The open nature of basketball gives it a large uncertainty that makes hard the tactical analysis of the situations that happen in the game. Specifically, screens are one of the offensive tactical elements most used in basketball and one example of a tactical situation that needs the highest preparation level to get a good performance in the competition. The aim of this study is to differentiate these player behaviors by gender using data mining and polar coordinates analysis. Therefore, one ad hoc observational tool made by 17 criteria and 97 exhaustive and mutually exclusive (E/ME) categories has been designed and validated using the data quality analysis (correlation coefficients and concordance index 0.98) and generalizability analysis (G coefficients 0.94) to perform such a study. The observational design is nomothetic, punctual, and multidimensional. A total of 176 ball screens situations have been analyzed for the men's category and 118 for women's category, corresponding to three different teams of each gender playing in the highest competition level in Spain during the 2018/2019 season using Hoisan software tool. The analysis of the relationships among behaviors has been performed using Polar Coordinates analysis as well as data mining analysis: clustering and decision tree classifier. Results show significant relationships that allow us to tactically interpret the pick and roll situations in men's and women's professional basketball players in Spain, allowing us to develop more intervention programs which will optimize training and improve players performance.