درخت حوزه‌های تخصصی

Purpose: Delayed onset muscle soreness (DOMS) is pain and stiffness that occurs several hours to several days after unusual or intense exercise. It is thought that this exercise causes small damage (micro trauma) to muscle fibers. The aim of the present study was to compare the effects of high-intensity resistance training and resistance retraining on serum levels of some indices of muscle damage in inactive young girls. Method: Twenty-four healthy inactive young girls voluntarily participated in the present study. They then randomly divided into two groups of 10. The muscle injury protocol included five stations of biceps and shoulder presses with a barbell, squats, chest press, and leg press. Each movement consisted of three sets of 8 to 12 repetitions, with an intensity of 75% of one repetition maximum. Serum levels of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase enzymes were measured before the activity and at intervals of 1, 26, and 48 hours after it. Analysis of variance with repeated measures and independent t-test were used to analyze the data at a significance level of p≥0.05. Results: there was no significant difference in the changes in creatine kinase, lactate dehydrogenase, and aspartate aminotransferase between the two groups at different stages of measurement after retraining (p<0.05). Conclusion: According to the results of the present study, it can be concluded that resistance training cannot be a significant influencing variable on the amount of muscle damage. However, more research in this field is needed.

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.