Yafteh

Background: Proliferation of adipose tissue increases leptin secretion and decreases adiponectin concentration. Exercise is an intervention to control and reverse this process. Therefore, the present study aimed to determine the effect of 8-week high-intensity interval training on leptin, adiponectin, and the ratio of leptin to adiponectin in overweight adolescent boys.
Materials and Methods: The present quasi-experimental study was conducted on overweight adolescent boys (13-18 years old, mean body mass index 27.05±1.4 kg/m²). A total of 30 participants volunteered who were divided into three groups of 10 people including short-term (9 sessions of 30-second training with 150-second rest), long-term (4 sessions of 150-second training with 240-second rest), and control group. The training groups performed high-intensity running sprints 3 times per week for 8 weeks. Data were analyzed using two-way repeated-measures ANOVA (3 groups×2 measurement times) and Bonferroni test.
Results: Performed high-intensity interval training failed to affect leptin, weight, and body mass index but increased adiponectin and decreased the ratio of leptin to adiponectin (P = 0.042) and fat percentage. No difference was observed between the two types of interval training in changing the level of leptin, adiponectin, fat percentage, and body mass index.
Conclusion: High-intensity interval training increases metabolic benefits in overweight adolescents by increasing adiponectin and subsequently decreasing the leptin/adiponectin ratio. Low exercise, no calorie restriction, and other factors affecting puberty may influence the research results.

Background: The fibroblast growth factor 21 is a protein that is involved in regulating glucose and fat metabolism. The present study aimed to investigate the effect of eight weeks of high-intensity interval training on serum levels of fibroblast growth factor 21 and insulin resistance in overweight young men.
Materials and Methods: In this semi-experimental study, 30 overweight young men (BMI<25 kg /m2) were purposefully selected and randomly divided to control (n=15) and experimental (n=15) groups. The experimental group performed ten repetitions of one-minute aerobic exercise (treadmill, elliptical trainer, or stationary bike) with an intensity of 80-75% of the target heart rate with one-minute active intermittent rest periods with an intensity of 35-40% of the heart rate for 8 weeks, 4 sessions per week. Fibroblast growth factor 21 and insulin resistance were measured 24 hours before starting the program and 48 hours after the last training session. Intragroup and Intergroup changes were analyzed using dependent and independent t-test, respectively.
Results: Serum levels of fibroblast growth factor 21 indicated a significant increase (t=6.94, P= 0.031) compared to that of the control group after 8 weeks of high-intensity interval training, but insulin resistance significantly decreased (t=5.81, P=0.008).
Conclusion: High-intensity interval training for 8 weeks can be prescribed as an optimal exercise protocol to increase serum fibroblast growth factor 21 and reduce insulin resistance in overweight young men.

Background: Prediabetes is an important risk factor for developing type 2 diabetes and cardiovascular diseases. The current study aims to investigate the changes in miR-204 and serum glucose following eight weeks of high-intensity interval training (HIIT) in the men with prediabetes.
Materials and Methods: In this quasi-experimental study with a pre-test/post-test design, 24 middle-aged men (aged 40-50 years) with prediabetes (Fasting blood sugar= 110-125 mg/dL) were randomly assigned to the training and control groups. The training group performed the HIIT (High Knee, Butterfly, Burpee, Kettlebell Snatch, and Scott Goblet) with an intensity of 80-90% of heart rate for eight weeks (three sessions in the first four weeks and four sessions in the second four weeks). The blood samples were taken from the subjects 48 hours before and after the last training session to analyze the level of miR-204, lipid profile, and the serum glucose level. Data were analyzed by using paired t-test and ANCOVA in SPSS v.25 software, considering a significance level of P˂0.05.
Results: The eight weeks of HIIT significantly reduced the serum levels of miR-204 (P=0.001), Triglyceride (P˂0.001), Cholesterol (P˂0.001), low-density lipoprotein (P˂0.001), and glucose (P=0.031) compared to the control group. Furthermore, after HIIT, a significant increase in the serum high-density lipoprotein level was observed (P˂0.001).
Conclusion: It seems that miR-204 is an appropriate indicator for regulating the blood glucose level in both diabetic and pre-diabetic men. Furthermore, HIIT can reduce the lipid profile by altering the expression of miR-204 and, subsequently, reducing the glucose level.                                 

Background: Dysfunction of mitochondria is associated with such diseases as obesity, cancer, and type 2 diabetes. Training plays a major role in the improvement of mitochondrial damage and oxidative stress. Therefore, the present study aimed to investigate the effect of eight weeks of high-intensity interval training on some mitophagy indices in the liver tissue, including BNIP3 and NIX in type 2 diabetic rats.
Materials and Methods: A total of 30 three-month-old adult male Wistar rats with a weight range (250-300 g) were randomly assigned to four groups of 10 series, including healthy control (C), Diabetic control (D), and diabetic+Training (D+T). The training protocol includes running with intensity at 85%-90% of maximum speed in 6-12 two-minute intervals five days a week for eight weeks. A method based on Western blotting was used to determine changes in the expression of BNIP3 and NIX proteins in the liver tissue of rats. The one-way analysis of variance and the Bonferroni post hoc test were used to analyze the data.
Results: Diabetes increased BNIP3 and NIX proteins; nonetheless, it was not significant. The changes of NIX in the trained diabetic group were about 57% less than in the diabetic control group, and this difference was significant (P=0.033), while BNIP3, despite a 37% decrease, did not change significantly (P>0.05).
Conclusion: Eight weeks of intense intermittent training caused a significant decrease in the expression of proteins involved in mitophagy in the training group. Nonetheless, arriving at a definite conclusion on these indicators and how they are affected by different conditions depends on conducting further studies.

Background: Aging can lead to a decrease in cardiac function and an increase in oxidative stress in the heart, which leads to cellular aging through mitochondrial dysfunction. The present study aimed to investigate the antioxidant effects of high-intensity interval training (HIIT) and genistein (Ge) consumption in the heart tissue of elderly rats.
Materials and Methods: In this experimental study, 30 female Sprague-Dawley rats aged 18 to 24 months were selected and divided into five groups of six rats, including 1) HIIT, 2) Ge, 3) HIIT + Ge, 4) control, and 5) sham. During eight weeks, groups 2 and 3 received 60 mg of Ge dissolved in DMSO per kilogram of body weight daily, and group 5 received 60 mg of DMSO per kilogram of body weight per day intra-peritoneally. In addition, groups 1 and 3 ran on the treadmill three times per week. For statistical analysis of data, Shapiro-Wilk, independent samples t-test, one-way ANOVA, and Tukey's post-hoc test were used.
Results: High-intensity interval training had a significant effect on increasing GPx and MDA (P<0.05), Ge led to a significant decrease in SOD (P<0.05); however, HIIT with Ge had not interactive effects on improving SOD, GPx, and MDA (P<0.05).
Conclusion: It seems that the antioxidant system is dependent on the intensity of exercise and the dose of genistein. Therefore, HIIT and Ge in this study have no interactive effect on the oxidant-antioxidant system in the heart of elderly rats.
 

Background: The predictive role of mean platelet volume (MPV) and red cell distribution width (RDW) in cardiovascular diseases has been proven. High-intensity interval training (HIIT) is a sustainable and effective method for improving cardiorespiratory fitness. Therefore, the present study aimed to investigate the effect of eight weeks of HIIT on MPV and RDW in inactive, normal-weight, and obese women.
Materials and Methods: In this semi-experimental research, 24 participants were voluntarily selected from a population of inactive, healthy, obese women and healthy women of normal weight aged 30 to 45 years. They were divided into two experimental groups, each consisting of 12 participants (normal-weight and obese). Both groups were in a circuit HIIT protocol for eight weeks, three sessions per week with an intensity of 90% HRmax for related exercises. Blood sampling was taken on two occasions: once before and once after a 12-hour fasting period and again 48 hours after the last training session. The analysis of covariance (ANCOVA) statistical test was employed to analyze variables at a significance level of P < 0.05.
Results: The results indicated that there was a statistically significant difference between the two obese and normal weight groups in the average decreases in MPV (P=0.045), red blood cell distribution width (RDW) (P=0.001), and high-density lipoprotein (HDL) (P=0.045).
Conclusion: High-intensity exercise may modulate MPV and other cardiovascular disease risk factors, such as high body mass index and high body fat percentage in middle-aged women, suggesting an effective, inexpensive, and accessible non-pharmacological method for reducing the risk of cardiovascular diseases.