درخت حوزه‌های تخصصی

Background: Plyometric training is defined as a quick, powerful movement involving a system of reactive exercises and an eccentric contraction, followed immediately by an explosive concentric contraction. Aim : This study aimed to determine the effect of plyometric and aerobic training on peak power and performance in female elite rowers. Materials and Methods: Sixteen female elite rowers with a minimum of 1 year’s competitive rowing experience were recruited to perform six weeks of plyometric or cycling endurance training for 30 min before practice on the water three days per week. Rowing performance was assessed through a 500-m rowing time trial (TT), while peak rowing power (PR) was evaluated by over three maximal trials of 15 s on the rowing ergometer. The recorded value for peak power was the highest wattage observed during the 15-s period. All statistics were performed using commercially available software (SPSS v. 23, Armonk, NY). Pre-planned t-test comparisons were used to determine significance at baseline in changes within both groups. Results: The results showed 500-m TT performance significantly improved for the plyometric group ( P < 0.05) but not for the endurance group ( P > 0.05). Moreover, PR was considerably higher in the plyometric group in post-test than endurance training. Conclusion: These results suggest that plyometric can improve rowing performance in female elite rowers, and rowing coaches should continue using this form of training. Coaches can perform plyometrics in conjunction with other strength training methods or as a warm-up before beginning rowing-specific training.

Background: China is the undisputed power of sports in the world today and due to the close relations of China and Iran in many different aspects, the bilateral scientific works can be considered as well. Aim : The purpose of this study was to analyze the opportunities for the development of championship sports with a look at the cooperation document between Iran and China. Materials and Methods: The present study was a qualitative (descriptive-analytical) type of library studies in terms of applied purpose and in terms of data collection, which examined scientific works including books, articles, and notes during 2010-2021 about Iranian sports and China took place. Results: The research findings showed that the Islamic Republic of Iran and China, as two superpowers of West and East Asia, can have different sports interactions with each other in team and individual disciplines, respectively. In addition, the Iranians can use sport as a starting point and a tool to facilitate and accelerate their political-trade relations by winning 76 and the Chinese by winning 696 medals in the Summer and Winter Olympics; For example, the Chinese in the fields of swimming and diving, gymnastics, table tennis and recently weightlifting have emerged as the undisputed power of the world, while Iran can also compete in team sports such as football, volleyball and even Basketball to share its experiences in human resource development as the most important precondition for national excellence with this country. Conclusion: All in all, sport as a facilitator between Iran and China can develop the future political communications. China is the pioneer of Olympic Games and 25 years agreement can lead to brilliant future for Iranians.

Football withdrawal has always created many psychological problems for players and it has had destructive effects on their health. The purpose of this study was to investigate the effects of perfectionism on the reduction stress and athletic burnout in football players. The statistical population of this study included all football players at youth level in Guilan, Iran. 378 players were selected as a sample size through random sampling method. A combination of valid and reliable standard questionnaires was distributed to collect the research data. Research hypotheses were analyzed by the Kolmogorov-Smirnov test, Pearson correlation coefficient, and linear regression. The SPSS software (version 24) was used for data analysis (α≤0.05). The results showed that there was a significant correlation between athletic burnout and positive perfectionism (-0.622), negative perfectionism (0.555), problem-oriented strategy (-0.358), and emotion-oriented strategy (0.401). According the results of this study, developing efficient plans with focusing on the psychological variables of perfectionism, stress, and athletic burnout can improve the coaches’ awareness of coaching behaviors as well as increasing athletes’ optimal mental performance and efficiency.