ترتیب بر اساس: جدیدترینپربازدیدترین
فیلترهای جستجو: فیلتری انتخاب نشده است.
نمایش ۱٬۱۰۱ تا ۱٬۱۱۲ مورد از کل ۱٬۱۱۲ مورد.
۱۱۰۱.

Physiological and Organizational Determinants of Safety in Extreme Sport Tourism (rafting, climbing, sky running, canyoning)

حوزه‌های تخصصی:
تعداد بازدید : ۲۰ تعداد دانلود : ۲۵
Purpose: Extreme sport tourism has become a rapidly expanding segment of the global tourism industry, involving high-risk activities such as rafting, climbing, sky running, and canyoning. The objective of this review was to synthesize current scientific evidence on the physiological and organizational determinants of safety in extreme sport tourism and to present an integrated framework applicable to diverse adventure sport contexts. Method: A narrative review methodology was adopted. Peer-reviewed studies published between 2000 and 2025 were identified through PubMed, Scopus, Web of Science, ScienceDirect, and Google Scholar. Included studies addressed physiological stress responses, environmental exposure, guide competence, safety management systems, and emergency preparedness in extreme or adventure sport settings. Findings were thematically synthesized across physiological and organizational domains. Results: The review identified key physiological determinants of safety, including cardiovascular strain, hypoxic and respiratory stress, thermoregulatory imbalance, dehydration, neuromuscular fatigue, and neuroendocrine stress responses, all of which influence performance, cognition, and decision-making under extreme conditions. Organizational determinants included structured risk assessment, guide training and certification, equipment standards, communication systems, emergency response planning, and organizational safety culture. Evidence indicated that inadequate organizational control amplifies physiological risk and contributes to accident occurrence. Conclusion: Safety in extreme sport tourism requires an integrated, multidisciplinary approach aligning human physiological limits with organizational management to improve participant safety and support sustainable destination development.
۱۱۰۲.

Synergistic Effects of Curcumin Supplementation and High-Intensity Interval Training on Mitochondrial Antioxidant Enzymes in the Hippocampus of Aged Rats

حوزه‌های تخصصی:
تعداد بازدید : ۲۸ تعداد دانلود : ۲۱
Purpose: Aging is accompanied by progressive mitochondrial dysfunction and increased oxidative stress, particularly within the hippocampus, a brain region highly vulnerable to metabolic impairment and redox imbalance. Curcumin, a polyphenolic compound with potent antioxidant and anti-inflammatory properties, and high-intensity interval training (HIIT), a time-efficient exercise modality known to stimulate mitochondrial biogenesis, may offer complementary neuroprotective benefits. This study examined the synergistic effects of curcumin supplementation and HIIT on mitochondrial antioxidant enzymes in the hippocampus of aged rats. Method: Thirty-two male Wistar rats (22–24 months) were randomly assigned to four groups: Control, Curcumin (100 mg/kg/day), HIIT, and Curcumin + HIIT. The 8-week HIIT protocol consisted of treadmill-based intervals performed five days per week, while hippocampal mitochondrial fractions were analyzed for superoxide dismutase 2 (SOD2), catalase (CAT), and glutathione peroxidase (GPx). Oxidative stress markers, including reactive oxygen species (ROS), malondialdehyde (MDA), and reduced glutathione (GSH), were also quantified. Results: Both curcumin and HIIT independently increased SOD2, CAT, and GPx activities (p < 0.01), but the combined intervention produced significantly greater enhancements across all enzyme systems (p < 0.001). ROS and MDA levels were markedly reduced in the Curcumin + HIIT group compared with all other groups (p < 0.001), while GSH content increased by more than 100% relative to controls. Effect sizes were large for all mitochondrial and oxidative stress outcomes, indicating robust physiological adaptation. Conclusion: These findings demonstrate that curcumin supplementation synergistically enhances the mitochondrial antioxidant and redox benefits of HIIT in the aging hippocampus. Integrating targeted nutraceuticals with structured high-intensity exercise may represent a promising strategy for mitigating age-related oxidative dysfunction and supporting long-term brain health.
۱۱۰۳.

Anthropometric Predictors of Acute Ventilatory Responses to Maximal Field Exercise in Adolescents

حوزه‌های تخصصی:
تعداد بازدید : ۲۵ تعداد دانلود : ۲۳
Purpose: The acute ventilatory response to exercise in adolescents is a critical indicator of cardiorespiratory fitness, yet the predictive power of basic anthropometric measures for this response, particularly in field-based settings, is not fully established. This study aimed to investigate the relationship between anthropometric variables (height, weight, BMI) and acute ventilatory responses both at rest and immediately following a maximal one-mile (1600m) field run in healthy adolescent boys. Method: In a pre-test/post-test experimental design, 80 healthy adolescent boys (mean age: 14.65 ± 1.22 years, height: 168.20 ± 9.72, body mass index: 19.54 ± 2.80) were selected via cluster sampling. Anthropometric data (height, weight, BMI) and estimated VO₂max were recorded. Pulmonary function variables (FVC, FEV₁, VC, TV, MVV) were measured via spirometry at rest and immediately after a maximal one-mile run. Stepwise multiple regression analysis was used to predict ventilatory responses from anthropometric and physiological variables. Results: Height, weight, and BMI were all significant predictors of pulmonary function (FVC, FEV₁, VC) in both pre- and post-test conditions (p < 0.05). Height emerged as the strongest single predictor. A slight but consistent decrease in mean FVC, FEV₁, and VC values was observed post-exercise. VO₂max was a weaker predictor compared to anthropometric measures. Conclusion: Basic anthropometric characteristics, most notably height, are strong and consistent predictors of pulmonary function in adolescent boys, both at rest and following acute strenuous exercise. These findings highlight the importance of using individual morphometric characteristics for accurately assessing and interpreting exercise-induced ventilatory responses in youth populations. Field-based testing provides a valid practical method for such evaluations.
۱۱۰۴.

Effects of resistance training and retraining on creatine kinase, lactate dehydrogenase, and aspartate aminotransferase enzymes in inactive young boys

حوزه‌های تخصصی:
تعداد بازدید : ۲۱ تعداد دانلود : ۳۰
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.
۱۱۰۵.

Lack of Correlation between Carrier Protein and Stress Hormone Fluctuations Following Acute Intensive Aerobic Exercise in Young Male Runners

حوزه‌های تخصصی:
تعداد بازدید : ۲۶ تعداد دانلود : ۲۴
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.
۱۱۰۶.

The effect of HIIT training on serum liver enzyme concentrations in obese men with nonalcoholic fatty liver disease

حوزه‌های تخصصی:
تعداد بازدید : ۱۵ تعداد دانلود : ۲۳
Purpose: Non-alcoholic fatty liver disease (NAFLD) is a common liver disorder associated with obesity, metabolic syndrome, and insulin resistance. It is often characterized by elevated liver enzymes, such as AST, ALT, and ALP, which are biomarkers of liver injury. Exercise, particularly high-intensity interval training (HIIT), has been shown to improve liver function by reducing these enzyme levels. This study aimed to evaluate the effects of a 6-week HIIT protocol on liver enzyme levels (AST, ALT, and ALP) in obese individuals with NAFLD. Method: This quasi-experimental study involved 20 obese participants diagnosed with NAFLD. They were randomly assigned to an experimental group (n=10) and a control group (n=10). The experimental group participated in a HIIT protocol for 6 weeks, while the control group maintained their usual lifestyle. Blood samples were taken before and after the intervention to measure serum AST, ALT, and ALP levels. Data analysis was conducted using paired t-tests and independent t-tests to compare pre- and post-intervention values within and between groups, respectively. Results: The experimental group showed a significant reduction in AST (p = 0.01), ALT (p = 0.03), and ALP (p = 0.04) after the intervention. In contrast, no significant changes were observed in the control group for any of the enzymes (p > 0.05). Between-group comparisons revealed significant differences in enzyme levels post-intervention (p = 0.03 for AST, p = 0.04 for ALT, and p = 0.05 for ALP). Conclusion: The results of this study suggest that HIIT may be an effective non-pharmacological intervention for improving liver function in obese individuals with NAFLD. Further studies with larger sample sizes and longer follow-up periods are needed to confirm the long-term effects of exercise on liver enzymes in this population.
۱۱۰۷.

Studying the effect of 12 weeks of combined training (resistance + aerobic) on serum levels of some cardiovascular risk factors in female patients with type 2 diabetes

حوزه‌های تخصصی:
تعداد بازدید : ۱۳ تعداد دانلود : ۲۶
Purpose: In many countries, type 2 diabetes has emerged as a chronic non-communicable disease. Type 2 diabetes is usually associated with increased cardiovascular risk factors. The role of physical activity has been proven as a useful intervention in the prevention, management and treatment of type 2 diabetes. The aim of the present study was to study the effect of 12 weeks of combined training (resistance + aerobic) on serum levels of some cardiovascular risk factors in patients with type 2 diabetes. Method: In this study, 22 individuals with type 2 diabetes, aged 30 to 60 years, participated. The subjects were randomly assigned to one of two combined training and control groups, 11 in number. The training program assigned to each group was carried out for 12 weeks and three sessions per week. To investigate the dependent variables, blood samples were taken from all subjects one day before and 48 hours after the last training session. Data analysis was performed using paired t-tests and independent t-tests (P<0.50). Results: After 12 weeks of participation in sports activities, the mean total cholesterol (p=0.001), low-density lipoprotein (p=0.001), triglyceride (p=0.011), and body mass index (p=0.01) in the combined training group (resistance + aerobic) significantly decreased, and high-density lipoprotein levels (p=0.036) in this group significantly increased after training interventions. Conclusion: According to the results of the present study, it seems that combined training improves the body's lipid profile by significantly reducing the levels of total cholesterol, low-density lipoprotein, triglyceride, and body mass index. Therefore, combined exercises are recommended as an effective intervention in reducing cardiovascular risk factors in type two diabetic patients.
۱۱۰۸.

The relationship between some serum osteoporosis markers and body mass index with lumbar bone mineral density inactive postmenopausal women

حوزه‌های تخصصی:
تعداد بازدید : ۱۳ تعداد دانلود : ۲۲
Objective: Menopause is a sensitive and challenging period for women, which leads to various problems such as osteoporosis and back pain. However, its effect on bone mineral density is still debatable. Therefore, the aim of this study was to determine The relationship between some serum osteoporosis markers and body mass index with lumbar bone mineral density in active and inactive postmenopausal women. Methods: The number of subjects was 41 active postmenopausal women and 45 inactive postmenopausal women aged 46 to 87 years. Serum alkaline phosphatase, calcium and phosphorus indices and anthropometric characteristics of the subjects were examined. Pearson correlation coefficient test was used to analyze the research data. SPSS version 26 software was used to analyze the data. Results: We observed a statistically significant correlation between serum levels of alkaline phosphatase, calcium, and phosphate with lumbar bone mineral density in the group of active postmenopausal women, and between body mass index, weight, and age with lumbar bone mineral density in both active and inactive postmenopausal women (p ≥ 0.05). While no significant correlation was found between other indices. Conclusion: Active postmenopausal women, by taking advantage of sports activity, in addition to having better health indicators, have provided the necessary stimulus for some hormonal mechanisms, mineral absorption, and calcium-phosphorus balance in order to reduce bone resorption.
۱۱۰۹.

Comparative Effects of Physical Activity on Respiratory Function in Young Adult Males: A Study of Sleep Quality Relationships

حوزه‌های تخصصی:
تعداد بازدید : ۲۰ تعداد دانلود : ۲۰
Purpose: This study aimed to compare respiratory parameters and sleep quality between physically active and inactive young adult males, while exploring correlations between these domains. Method: In a semi-experimental design, 15 active males (aged 20–23 years; ≥8 hours/week moderate-to-vigorous activity; >2 years sports experience) and 15 inactive males (≤3 hours/week activity; no sports experience) were recruited. Anthropometric measures (height, weight, BMI, body fat percentage, heart rate) were assessed. Pulmonary function—including forced vital capacity (FVC), vital capacity (VC), maximum voluntary ventilation (MVV), forced expiratory volume in one second (FEV1), percentage predicted FEV1 (%FEV1), and maximum expiratory flows at 25% and 75% of FVC (MEF25%, MEF75%)—was evaluated via spirometry (Fukuda ST-95) per American Thoracic Society guidelines. Sleep quality was quantified using the Pittsburgh Sleep Quality Index (PSQI). Independent t-tests compared groups; Pearson correlations and multiple linear regressions examined associations (α = 0.05). Results: Active participants displayed superior respiratory metrics ( p < 0.05): higher FVC ( p = 0.023), VC ( p = 0.002), MVV ( p = 0.001), FEV1 ( p = 0.001), %FEV1 ( p = 0.001), MEF25% ( p = 0.026), and MEF75% ( p = 0.042). PSQI scores were significantly lower (better) in the active group (4.13 ± 1.18) versus inactive (6.53 ± 2.50; p = 0.002). No baseline differences emerged in age, height, weight, heart rate, fat percentage, or BMI ( p > 0.05). In the active group, each 1-unit increase in FEV1, MVV, VC, FVC, and MEF75% was associated with corresponding reductions in sleep quality scores of 0.217, 0.127, 0.370, 0.386, and 0.194 units, respectively (all p > 0.05). Regressions and correlations between respiratory indices and sleep quality were non-significant in both groups. Conclusion: Regular physical activity enhances sleep quality and respiratory function in young males, though direct mechanistic links were not evident in this cohort. These findings advocate exercise as a non-pharmacological strategy for addressing sleep and pulmonary health, warranting larger, diverse studies to elucidate interactions.
۱۱۱۰.

The effect of twelve weeks of resistance training and a detraining period on relative left ventricular wall thickness in inactive men

حوزه‌های تخصصی:
تعداد بازدید : ۱۹ تعداد دانلود : ۲۹
Purpose: Physical activity is associated with higher left ventricular mass but also reduced risk of cardiovascular outcomes. The purpose of the present research was to investigate the effect of twelve weeks of resistance training and a detraining period on relative left ventricular wall thickness in inactive men. Method: Twenty-four inactive men who met the inclusion criteria and were able to participate in the exercise protocol were randomly divided into two resistance training groups (n=12) and control group (n=12). Anthropometric characteristics, body composition, and relative wall thickness (RWT) were measured using echocardiography at three time points: before the start of exercise, at the end of 12 weeks of exercise, and after a 6-week period of non-exercise. The exercise protocol consisted of 12 weeks of exercise (three sessions per week) followed by 6 weeks of non-exercise. Data were analyzed using independent t-tests and repeated measures analysis of variance at a significance level of p < 0.05 using SPSS software version 24. Results: The results showed that a significant change in RWT was observed between pre-test and post-test measurements in both groups (p < 0.05) and significant changes in RWT were also observed during the detraining period in the training group (p < 0.05). Conclusion: It can be concluded that 12 weeks of resistance training can lead to beneficial changes in cardiac structure in inactive men. A 6-week detraining period can lead to negative effects on these adaptations. Therefore, it is recommended that individuals participate in regular and structured resistance training to maintain these positive adaptations.
۱۱۱۱.

مدل سازی عوامل روان شناختی مؤثر بر توسعه پایدار کارآفرینی ورزشی در ورزشکاران(مقاله علمی وزارت علوم)

حوزه‌های تخصصی:
تعداد بازدید : ۱۹ تعداد دانلود : ۳۱
هدف: در دنیای امروز، توسعه کارآفرینی در ورزش نیازمند شناخت دقیق عوامل روان شناختی مؤثر بر رفتار و عملکرد ورزشکاران است. از این رو پژوهش حاضر باهدف مدل سازی عوامل روان شناختی مؤثر بر توسعه پایدار کارآفرینی ورزشی در میان ورزشکاران نخبه عراق انجام شده است. مواد و روش ها: روش پژوهش از نوع کیفی با رویکرد تحلیل مضمون بوده و داده ها از طریق مصاحبه های نیمه ساختاریافته با ۱۹ ورزشکار، مدیر و مربی ورزشی نخبه عراق که در حوزه کارآفرینی ورزشی فعال بودند، گردآوری شد. نمونه گیری به شیوه هدفمند و گلوله برفی انجام و تحلیل داده ها با استفاده از روش تحلیل مضمون در نرم افزار MAXQDA نسخه Pro صورت گرفت. یافته ها: نتایج پژوهش نشان داد که توسعه پایدار کارآفرینی ورزشی تحت تأثیر هفت عامل روان شناختی کلیدی شامل انگیزش و تعهد شخصی، خودباوری و کنترل شخصی، تاب آوری و مقابله با چالش ها، خلاقیت و نوآوری، توانایی های ارتباطی و اجتماعی، ریسک پذیری و تصمیم گیری و برنامه ریزی و هدف گذاری قرار دارد. این عوامل در قالب ۱۵ مضمون سازمان دهنده و 48 مضمون پایه شناسایی و دسته بندی شدند. نتایج نشان داد که ورزشکاران کارآفرین از ویژگی هایی مانند انگیزه درونی، پشتکار، تحمل شکست، توانایی سازگاری با تغییرات، تفکر خلاق، مهارت های ارتباطی قوی، پذیرش ریسک و توانایی برنامه ریزی بلندمدت برخوردارند. نتیجه گیری: یافته های این پژوهش می تواند برای سیاست گذاران ورزشی، مربیان و نهادهای اقتصادی فعال در حوزه ورزش جهت تدوین راهکارهای حمایتی و توسعه ای مورداستفاده قرار گیرد.
۱۱۱۲.

The relationship between several respiratory indices and sleep quality in active and inactive adult men

حوزه‌های تخصصی:
تعداد بازدید : ۲۲ تعداد دانلود : ۱۶
Purpose: With increasing age, sleep quality decreases and sleep complaints are common in the elderly, especially inactive individuals. Therefore, the aim of this study was to investigate the association between several respiratory indices and sleep quality in active and inactive adult men. Method: Twenty elderly men with a mean age of 70.18±8.21 years, height of 163.23±5.10 cm, and weight of 71.20±7.11 kg participated voluntarily and after obtaining informed consent, randomly divided into two active and inactive groups (10 people in each group). Respiratory indices were measured using Microlab spirometry. The Pittsburgh questionnaire was used to assess sleep quality. Independent t-tests and Pearson correlation coefficient were used to analyze the data. Results: In the active group, the mean sleep quality score was significantly lower than that of the inactive group (p=0.013). Maximum voluntary ventilation (p=0.021), forced vital capacity (p=0.033), peak expiratory flow 25-75%, and forced expiratory volume in 1 second (p=0.046) parameters were significantly higher in the active group than in the inactive group. Conclusion: It seems that exercise can be an effective factor in improving respiratory system function and sleep quality in inactive adult men.

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