درخت حوزه‌های تخصصی

Purpose: This study aimed to investigate the effect of PMS on aerobic, anaerobic, and cognitive performance in female combat athletes. Method: In this semi-experimental study with a repeated measures design, 20 female combat athletes (mean age: 24.5±2.1 years) were assessed during two phases of their menstrual cycle: the PMS phase (7-10 days before menstruation) and the non-PMS phase (days 7-14 of the cycle). Aerobic performance was measured using the Bruce treadmill test, anaerobic performance was assessed by the Wingate test, and cognitive performance was evaluated through simple and choice reaction time tests. Statistical analyses were performed using paired t-tests and Pearson correlation (p<0.05). Results: The findings showed a significant reduction in VO₂ max (6.2%), time to exhaustion, and a significant increase in maximal heart rate and Rate of Perceived Exertion (RPE) during the PMS phase compared to the non-PMS phase (p<0.05). Anaerobic performance also declined, with a reduction in peak power (6.2%) and mean power (7.5%), an increase in fatigue index (16.2%), and lower blood lactate levels (p<0.01). Cognitive performance deteriorated during PMS, demonstrated by increased simple (16.7%) and choice (16.6%) reaction times, more errors, and decreased accuracy (p<0.01). Furthermore, there was a significant positive correlation between PMS symptom severity and VO₂ max reduction (r=0.72), as well as between blood lactate levels and reaction time (r=0.65) (p<0.01). Conclusion: PMS negatively affects aerobic, anaerobic, and cognitive performance in female combat athletes. These findings highlight the importance of considering the menstrual cycle phases in designing training and competition schedules for female athletes to optimize performance and prevent potential declines associated with PMS.

We were very interested in the recent research focused on evaluating cardiovascular performance in young populations. The maximal oxygen pulse (O₂Pmax), calculated as the ratio of peak oxygen uptake (VO₂peak) to peak heart rate (HRpeak), has become an important, non-invasive marker for assessing cardiopulmonary function. Nevertheless, direct measurement through cardiopulmonary exercise testing (CPET) is often impractical for large-scale studies. highlighting the need for reliable estimation methods. Although several such protocols are available for adults. their accuracy in adolescents—who experience significant physiological changes—has not been thoroughly validated. Our study sought to address this by comparing O₂Pmax estimates derived from one laboratory-based and three field-based exercise tests against a standard reference in adolescent males. We conducted a cross-sectional study involving 60 healthy adolescent boys (mean age 16.05 ± 0.81 years). Participants underwent four exercise tests in a randomized order: a Graded Exercise Test (GXT) on a treadmill, two cycle ergometer tests (PWC195 and PWC212)

Purpose: The aim of this study was to investigate the effect of high-intensity interval training on serum levels of irisin, follistatin, and metabolic status of overweight and obese women. Methods: The current research was a semi-experimental type with a pre and post-test design. 30 women with an average age of 22.9±2.11 years, weight 82.45±6.1 kg, BMI above 28 kg/m2) voluntarily participated and they were randomly divided into two groups of 15 people including HIIT (4 bouts of 60 seconds of running at an intensity of 80-90% HRmax with a 4-minute rest in the first four weeks) and control (did not have a regular exercise program). Blood samples were taken 24 hours before the start of the training period and 48 hours after the end of the last session, to measure irisin, Follistatin, and metabolic status, by ELISA method. Then, an independent t-test was used to examine changes between groups, and a correlated t-test was used for intragroup comparison. Data analysis was done by SPSS version 25 software at a significance level of 0.05. Results: After 8 weeks of intervention, the HIIT group showed that HIIT exercises led to a significant increase in irisin(p=0.25) and follistatin(p=0.12), triglyceride (p=0.30), and total cholesterol levels. (p=0.41), LDL (p=0.14), VLDL (p=0.17), weight (p=0.31), fat percentage (p =0.21)) and BMI (p=0.251); And there was a significant increase in maximum oxygen consumption (p=0.11). However, no significant change was observed in the amount of HDL (p=0.55). Conclusion: According to the findings of the present study, in order to maintain or prevent the decrease in bone density of postmenopausal women, resistance exercises can be recommended.

Purpose: For most trainers, the relationship between training volume and intensity as key components is a very important and effective issue. Therefore, the aim of the present study was to investigate the relationship between two key components of exhausting running at Heart Rate Deflection Point (HRDP) in girls. Methods: A number of 40 girls of physical education of Mohaghegh Ardabili University were selected as subjects with an age range of 19 to 23 years. Then, they ran individually in four separate sessions with an intensity of 70, 80, 90 and 100% of heart rate breaking point with a minimum interval of 72 hours. Using non-linear regression, the relationship between exercise volume and intensity was analyzed. Results: The findings showed that the inverse relationship between the volume (as a dependent variable) and the intensity (as an independent variable) of exhausting running at the HRDP of young girls' follows the non-linear 2nd degree function. Conclusion: According to the results of this study, it can be said that the inverse relationship between the volume and the intensity of running is non-linear. The noteworthy point is that in this estimation, the training volume was fitted based on the intensity, the relevant equation, which has a practical aspect for sports science trainers and researchers. Heart rate, as an important physiological index available to all coaches, can easily estimate the running time of young girls using the fitted equation.