درخت حوزه‌های تخصصی

Purpose: Unusual or intense exercise causes minor damage (microtrauma) to muscle fibers. It is thought that this damage is accompanied by the release of certain enzymes into the blood serum. The aim of the present study was to investigate the effect of resistance training and retraining on the enzymes creatine kinase, lactate dehydrogenase, and aspartate aminotransferase in inactive young boys. Method: Twenty-four healthy inactive young boys volunteered for the present study and were randomly divided into two groups of 10. The exercise protocol consisted of five stations of biceps and shoulders with a barbell, squats, chest presses, and forearm presses. Each movement consisted of three sets of 12 repetitions. The exercise intensity was 75% of one repetition maximum. Serum levels of the enzymes creatine kinase, lactate dehydrogenase, and aspartate aminotransferase were measured before the activity and at intervals of 1 and 48 hours thereafter. For data analysis, repeated measures analysis of variance and independent t-test were used at a significance level of p≥0.05. Results: The results of the present study showed that the levels of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase enzymes increased in both resistance training and resistance retraining groups compared to the pre-test at time intervals of 1, and 48. No differences were observed in serum levels of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase between the two groups during and after retraining (p>0.05). Conclusion: Retraining may not be a significant variable affecting recovery after muscle injury. However, more research is needed in this area.

Purpose: Vigorous physical exercise causes notable alterations in the circulatory system, affecting stress hormones and plasma proteins. Cortisol serves as a primary glucocorticoid hormone, while albumin, globulin, and hemoglobin function as important carrier proteins. However, how cortisol levels after exercise interact with these proteins is not well understood. This research aimed to explore the association between serum cortisol and the levels of albumin, globulin, and hemoglobin following a single session of intense aerobic exercise in young male runners. Method: Twelve healthy young male runners (average age 21.38 ± 0.95 years; VO₂max 50.81 ± 2.35 ml/kg/min) completed a 15-minute Balke treadmill test. Blood samples were collected before exercise, immediately after, and three hours post-exercise (recovery) to assess serum cortisol, albumin, globulin, and hemoglobin concentrations. Hematocrit measurements were used to adjust for changes in plasma volume. Statistical analysis involved one-way repeated measures ANOVA with Tukey’s post hoc test and Pearson correlation. Results: Immediately after exercise, there were significant increases in cortisol (61.4%), albumin (7.5%), globulin (10.5%), and hemoglobin (10.5%) (p<0.05). After three hours of recovery, cortisol, albumin, and hemoglobin levels returned to baseline, whereas globulin remained significantly elevated (p<0.05). No significant correlations were detected between cortisol changes and any of the carrier proteins at any time point (p>0.05). Conclusion: A single session of intense aerobic exercise markedly raises serum cortisol and key carrier proteins in young runners. The absence of correlation between cortisol and these proteins suggests that their immediate post-exercise increases are likely driven by factors other than cortisol fluctuations, such as hemoconcentration and changes in hydrostatic pressure, rather than direct hormonal stimulation.

Dynamic Assessment (DA) has increasingly been recognized as a promising approach for integrating assessment and instruction in second language learning. Despite their growing application, limited research has systematically compared the two major DA paradigms (i.e., interactionist and interventionist), particularly regarding their short- and long-term effects on learners’ speaking performance. The present study aims to address this gap by investigating the immediate and delayed impacts of interactionist and interventionist DA on English as a foreign language (EFL) learners’ speaking complexity, accuracy, and fluency (CAF). Eighty-six advanced EFL learners from a language center in Tehran, Iran were assigned to three groups based on the Oxford Placement Test. Following a speaking pretest, learners in the experimental groups received eight sessions of either interactionist or interventionist DA, while the control group underwent regular speaking assessment. An immediate and a delayed speaking post-test were used to evaluate both short-term progress and retention. Two trained raters scored the CAF measures, and the data were analyzed using repeated-measures two-way ANOVA and MANOVA. The findings indicated no significant differences between the two DA approaches; however, both experimental groups significantly outperformed the control group on the immediate and delayed post-tests. These results suggest that regardless of the mediation type, DA effectively enhances learners’ speaking performance and promotes the durability of learning gains. The study highlights the pedagogical value of embedding DA-based mediation into routine speaking assessment, enabling teachers to provide targeted scaffolding that supports both immediate improvement and longer-term development in learners’ oral proficiency.

Creativity, learning style, and metacognition are significant factors in education. Many research studies have been conducted on these three factors, but few studies have been carried out on the correlations among these factors and second/foreign language (L2) writing accuracy and fluency. Therefore, this mixed-methods study tried to clarify the best predictors of writing accuracy and fluency among these three factors. To achieve this purpose, 120 Iranian English as a foreign language (EFL) learners were selected based on the results of the Oxford Quick Placement Test (OQPT). Three types of Questionnaires were used to collect data. In addition, the participants wrote about the intended topics to check their writing accuracy and fluency. Moreover, the accuracy and fluency frameworks were applied to rate writings. Further, a semi-structured interview was utilized. To analyze the data, the multiple regression analysis was run. The findings indicated all these three factors were the best predictors of writing accuracy among intermediate learners, while metacognition was the best predictor of writing accuracy among advanced learners. In addition, learning style and metacognition were the best predictors of writing fluency among advanced learners. This study has some significant implications for learning. The most important implication is that learners can become aware of their creativity levels, learning styles, and metacognitive activities. In addition, the findings can enrich the literature concerning the predictors of writing accuracy and fluency among these three variables.