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ترتیب بر اساس: جدیدترینپربازدیدترین

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نمایش ۱ تا ۳ مورد از کل ۳ مورد.
۱.

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

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تعداد بازدید : ۷ تعداد دانلود : ۵
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.
۲.

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

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تعداد بازدید : ۷ تعداد دانلود : ۸
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.
۳.

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

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تعداد بازدید : ۶ تعداد دانلود : ۴
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.

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