درخت حوزه‌های تخصصی

The aim of the current research was to investigate the behavioral intention of coaches in virtual reality with considering the roles of Perceived Usefulness, Enjoyment, Performance Expectancy, Self-Efficacy, and Ease of Use. To collect the research data, a researcher-developed questionnaire with two sections was used. The first section included participants' demographic information, and the second section was used to collect data on research dimensions and variables. All questionnaires in this study utilized a 5-point Likert scale. The statistical population of this research included all sports coaches in Guilan province, Iran, both in individual and team disciplines, with a sample size of 350 individuals. SPSS software was employed for descriptive statistics, and Smart PLS was used for structural equation modeling. The results indicated that perceived usefulness, self-efficacy, enjoyment, ease of use, and performance expectancy have a positive and significant impact on the intention towards virtual reality behavior. Considering the current findings, the use of virtual reality in sports coaching can be recognized as a powerful tool for enhancing athletes' learning experiences, increasing enjoyment, and fostering a stronger and better inclination for active participation in sports activities.

Effective strategic leadership entails the implementation of diverse management strategies to develop a forward-looking perspective for the organization. Such a perspective enables the organization to adjust and remain competitive in a continuously changing economic and technological environment. This study aimed to design a strategic leadership model for sports federations in Iran. This study was applied in terms of purpose and adopted a mixed method with an exploratory approach. The statistical population of the qualitative study consisted of experts in the field of sports federations who were selected purposefully, and finally,  14 experts were selected as the research participants based on data saturation approach. The statistical population in the quantitative phase included 319 subjects (president, vice-president, secretary, and three members of the Board of Directors of sports federations) selected through stratified random sampling. The research data collection tool in the qualitative phase was a semi-structured interview whereas, in the quantitative section, a researcher-made questionnaire was developed from interviews' data. Data in the qualitative phase were analyzed using experts’ points of view, and in the quantitative phase, exploratory factor analysis, confirmatory factor analysis, divergent and convergent validity, and structural equation tests were used. Moreover, the face, content, and construct validity of the instrument were confirmed. Finally, the model of strategic leadership of sport federations was presented with seven factors including strategic orientation, human resources development, learning strategy, team leadership, strategic control, effective interaction culture, and ethical strategy.

We have reviewed the coaches' role in German talent identification and development football programs and followed the qualitative meta-synthesis method with Sadowski and Barroso's approach. We verified 56 documents and extracted 695 nonrepetitive open codes and 135 concepts. We showed that coaches' roles in a talent program consists of Competency, Leadership, and Organizational components. Competency components include selection, training, coaching, and performance. Leadership components include Technical and DFB & DFL. Finally, the Organizational components comprise the Double Pass, coordinators, and DFBnet. Properly organizing and equilibrium between these three parts can leverage and lead to successful coaches and the program. According to the critical role of alent programs and coaches in sports development, setting up national TID and TDE programs, especially in sports, are very important. Implementing a large-scale project with various criteria is complex; because it requires high cooperation, mutual understanding, and national determination. Many employees are involved in such systems with instrumental, scientific, experimental, and specialized aspects.

Background: Caffeine is widely recognized as a potent ergogenic aid commonly used to enhance exercise performance and recovery. However, individual responses to caffeine can vary significantly, a variability that might be explained by genetic differences.Aim: This study aimed to investigate the influence of the CYP1A2 rs762551 SNP on the effects of caffeine (CAF) consumption on growth hormone (GH) and testosterone (TS) levels response to resistance exercise (RE) in male athletes.Materials and Methods: Thirty resistance-trained men (mean age 21.72±4.06 years, weight 77.31±14.07 kg, height 179.31±5.08 cm) participated in a randomized, double-blind, placebo-controlled, crossover study. They consumed either CAF (6 mg/kg) or placebo (PL; 6 mg/kg maltodextrin) one hour before performing a RE protocol including three sets with 85% of 1RM and two-minute rest. CYP1A2 genotyping categorized participants as AA homozygous ("fast" metabolizers) or AC heterozygous ("slow" metabolizers). GH and TS levels were measured by ELISA methods.Results: Repeated measures ANOVA showed significant differences in GH levels across time (F=10.94, P=0.000), with significant time-group (F=4.3, P=0.019) and time-genotype-group interactions (F=3.83, P=0.024). One-way ANOVA indicated significant differences in GH levels between CAF and PL conditions in AA individuals, but not in AC/CC genotypes. For testosterone, significant effects of time (F=14.88, P=0.000) and time-group interaction (F=3.197, P=0.045) were observed. Post-RE CAF supplementation significantly increased serum GH and TS levels in AA individuals compared to PL. Both CAF and PL groups showed increased serum hormone concentrations post-exercise.Conclusion: In conclusion, the study demonstrated that caffeine consumption significantly increased serum levels of growth hormone and testosterone in individuals with the AA genotype of the CYP1A2 rs762551 SNP. These findings suggest that genetic variations play a role in the hormonal response to caffeine, which may have implications for exercise performance and recovery strategies.

Background: In the past few years, the increasing importance of the impact of exercise on physical and mental health has caused mobility wave around the world. Nevertheless, in Iran, a few people participate in physical activities. Aim: This study aimed to assess the reasons of nonparticipation in physical activity in Iran. Materials and Methods: This research is a descriptive and analytical approach conducted as a field study. The population of this research includes all people in Iran. Results: The results revealed that this factors are effective: three factors in individual characteristics variable (lack of sports skills, fatigue and impatience, fear of injury), four factors in inhibitor variable (lack of access to sports facilities and venues, poor quality of sports facilities and venues, being too busy, low income), four factors in environmental driving variable (lack of proper planning for sports, lack of awareness of the advantage of sport activities, feeling embarrassed after the loss, low number of exclusive sports facilities) and two factors in sports features variable (fear of winning and losing in sports, high intensity and duration of sport activities). Conclusion: Findings indicated that the environmental variable and inhibitor variable were more effective than two other variables, hence authorities and planners should pay more attention to these obstacles and problems with better management and provision of infrastructure facilities. These problems must be solved and strategies must be developed for promotion of sports in the country.