درخت حوزه‌های تخصصی

Background: Fatigue as one of the physiological factors can affect the physical performance of athletes. This issue is more important in young athletes and can expose them to injury. Aim: The purpose of this research was to investigate the effect of functional fatigue on the performance and landing mechanics of adolescence taekwondo athletes. Materials and Methods: This was a semi-experimental study. Participants were 20 male teenage taekwondo players. Pre-fatigue measurements included side-jump tests, figure-8 hop tests, and single-leg triple jump tests, as well as a lower limb biomechanics assessment using a landing error scoring system. After the functional fatigue protocol was applied, all the pre-fatigue variables were evaluated again. In order to examine the intra-group changes of the research variables in the pre and post-test stages, the paired t-test at a significance level of P≤0.05 was used. Results: The paired-t test results revealed that following fatigue induction, performance in the side-jump and figure-8 hop tests significantly deteriorated (P<0.05). Additionally, performance in the single-leg triple hop test declined (P<0.05). Moreover, landing error significantly increased (P<0.05). Conclusion: The finding of this study indicated that after applying fatigue, the subjects' performance decreased and the biomechanical error of the lower limbs increased. Fatigue can significantly impact adolescent taekwondo athletes' performance and biomechanics. So, taekwondo coaches should implement effective strategies to mitigate fatigue, enhance athletes' conditioning, and optimize their performance in training and competitions.

Purpose: The aim of this study was compares the effects of 10 weeks High Intensity Interval training (HIIT) and moderate intensity aerobic training (MIAT) on serum levels of homocysteine and some cardiovascular risk factors in overweight inactive men. Methods: In this semi-experimental study, nineteen overweight men voluntarily participated in this study and were randomly divided to 2 Groups: High Intensity Interval training (HIIT) and moderate intensity aerobic training (MIAT). Subjects performed training programs for 10 weeks, 3 sessions per week. The levels of homocysteine and lipid profile were measured before and after 10 weeks of training programs. For statistical data analysis, independent and paired t tests were used and considered significant at a p≤0.05.   Results: The results of this study showed that both High Intensity Interval training and moderate intensity aerobic training caused a significant reduction of homocysteine levels (P≤0.05). After 10 weeks of high -intensity periodic exercise, cholesterol levels (p = 0.001), LDL (p = 0.002) decreased significantly and HDL levels were significantly increased (p = 0.001), In MIAT training group, only a significant reduction in cholesterol was found (P=0.006). Conclusion: According to the results of this study, it seems that both High Intensity Interval training and moderate intensity aerobic training have favorable effects in reducing body weight and some cardiovascular risk factors.

The purpose of this study was to investigate the level of physical activity of faculty members at Allameh Tabatabai University during the coronavirus pandemic. This applied research has been done by a descriptive method. The statistical population of the study was the Allameh Tabatabai University faculty members in Iran. 284 people were selected through the available sampling method. A valid and reliable researcher-developed questionnaire was used for data collection, and a T-test was conducted for data analysis. The results of this study showed that the faculty members of the university do not have intense and moderate activities during the COVID-19 pandemic. But the general knowledge about the benefits of exercising during the coronavirus period has increased. In a general conclusion, COVID -19 crisis has created inactivity among university faculty members. Therefore, it is necessary to design and implement plans to increase the physical activity level among faculty members.