Original Article
biochemistry and metabolism
Ghasem Torabi Palat Kaleh; Ahmad Abdi; asieh abbassi daloii
Abstract
Background and Purpose: Aging is a complex physiological process that involves progressive loss of body function and degradation of DNA strands located at the ends of chromosomes-telomeres. The capacity of cells to divide is limited by telomere length, as an excessive shortening of telomeres causes cellular ...
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Background and Purpose: Aging is a complex physiological process that involves progressive loss of body function and degradation of DNA strands located at the ends of chromosomes-telomeres. The capacity of cells to divide is limited by telomere length, as an excessive shortening of telomeres causes cellular senescence. Exercise training and omega-3 prevent the shortening of telomeres by affecting telomerase. The aim of the present study was to investigate the effect of aerobic training with omega-3 on some shelterins and telomerase of heart tissue in elderly high-fat diet rats.Materials and Methods: In this experimental study, 40 male Wistar rats (mean weight 311.32±26.95 g) were obtained from the Pasteur Institute and transferred to the laboratory. After transferring the rats to the laboratory, they were randomly divided into five groups: Normal Diet (ND), High-Fat Diet (HFD), High-Fat Diet-Training (HFDT), High-Fat Diet-Omega3 (HFDω3), and High-Fat Diet-Training-Omega3 (HFDTω3). HFD induction was performed using a high-fat diet containing 17% protein, 43% carbohydrate, and 40% fat. The supplement groups received 1 g of Omega3 (per kg of body weight) orally during the intervention period. The aerobic exercise program at the beginning consisted of running on a treadmill at a speed of 10 m/min, 0-degree incline, for 15 minutes. The speed and duration gradually increased to 16 meters per minute and 50 minutes in the last session. Running was carried out for 8 weeks and five days a week. Data were analyzed by one-way analysis of variance and Tukey post hoc test at the P < 0.05.Results: Induction of HFD significantly decreased the expression of TRF2 (P = 0.002), TERT (P = 0.024) and increased TRF1 (P = 0.0001) compared to the ND group. Exercise and omega-3 significantly increased the expression of TRF2 and TERT in HFD rats (P < 0.05). Also, TRF2 and TERT expression changes were higher in the HFDTω3 group compared to HFDT (P = 0.023 and P = 0.044, respectively) and HFDω3 groups (P = 0.021 and P = 0.042, respectively).Conclusion: The results of the present study showed that elderly and HFD are associated with a decrease in TRF2, TERT and an increase in TRF1 in heart tissue, and aerobic exercise and omega-3 consumption can reverse this trend. Considering the role of shelterins and telomerase in cellular function, it seems that changing the levels of these indicators following physical activity and using omega-3 supplements can partially prevent the occurrence of many heart diseases caused by aging and obesity.
Original Article
Sports Physiology (General)
Saed Dastaan; Saeid Naghibi; Maryam Vatandoust
Abstract
Background and Purpose: The expansion of fat tissue depends on its angiogenesis rate, and exercise activities affect various angiogenic factors in this tissue. With the expansion of fat tissue and adipogenesis, a dense and closed capillary network is formed in this tissue, which can suppress angiogenic ...
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Background and Purpose: The expansion of fat tissue depends on its angiogenesis rate, and exercise activities affect various angiogenic factors in this tissue. With the expansion of fat tissue and adipogenesis, a dense and closed capillary network is formed in this tissue, which can suppress angiogenic factors. If there is a wide capillary network and angiogenic factors such as VEGF-A in this tissue, the expansion of fat tissue can be prevented. The aim of this study was to investigate and compare the effect of a variety of endurance exercises on the expression of angiogenic genes vascular endothelial growth factor (VEGF-A) and thrombospondin-1 (TSP-1) in the subcutaneous fat tissue of rats.Materials and Methods: In this experimental study, 32 male Wistar rats aged eight weeks and weighing 237 ± 33 grams were randomly divided into four equal groups of control, high-intensity progressive continuous aerobic training (HIT), moderate-intensity continuous aerobic training (MIT) and, high-intensity interval aerobic training (HIIT). The treadmill training protocols consisted of eight weeks, so that the HIT training consisted of running at a speed of 20 m/min or at an intensity of 65% of the maximum oxygen consumption (VO2max), with a gradually increasing slope for 30 minutes. MIT training consisted of running with an intensity of 65% VO2max for 37 minutes, and HIIT training consisted of four high-intensity intervals with four minutes of running with an intensity of 90-100% VO2max and four low-intensity intervals with a duration of three minutes with 50-60% VO2max (28 minutes in total). Finally, 48 hours after the last training session, the subcutaneous fat tissue was isolated and the expression of VEGF-A and TSP-1 genes in the subcutaneous fat tissue was measured by RT-qPCR method. The resulting data were analyzed using a one-way analysis of variance and Tukey's post hoc test, and the significance level was considered P ≤ 0.05.Results: The findings of the present study showed that all three exercise interventions significantly increased the expression of the VEGF-A gene in subcutaneous fat tissue; But only HIT training could significantly reduce the expression of TSP-1 in this tissue (P ˂ 0.05). Also, the increase in VEGF-A expression was significantly higher after HIT training compared to HIIT (P ˂ 0.05).Conclusion: According to the findings of this study, high-intensity and progressive continuous aerobic training is probably the most desirable training method to increase angiogenesis in subcutaneous fat tissue. These types of exercises can be effective in reducing fat mass by improving blood supply to fat tissue.
original article
Sports Physiology (General)
Zahra Noruzi; Javad Nemati; Mohsen Salesi; Rasoul Rezai; Mohammad Hemmatinafar
Abstract
Background and Purpose: increased oxidative stress is the main characteristic of all types of age-related injuries. Regarding the role of physical activity in adaptive responses to oxidative stress and importance of nutritional supplements, the aim of this study was to investigate the effect of six weeks ...
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Background and Purpose: increased oxidative stress is the main characteristic of all types of age-related injuries. Regarding the role of physical activity in adaptive responses to oxidative stress and importance of nutritional supplements, the aim of this study was to investigate the effect of six weeks of high-Intensity interval training along with the consumption of coenzyme Q10 supplements on the values of Nrf2, NQO1 in the soleus muscle of elderly rats. Materials and Methods: The current research was an experimental and fundamental type, which was conducted in the animal laboratory of Shiraz University. Forty-four elderly male Wistar field rats were used to carry out the research. After a one-week familiarization with the training environment, the animals were randomly divided into high-intensity interval training groups, a supplemental group, high-intensity interval training group with supplementation, and a control group (11 in each group). Subjects in the training groups performed interval high-intensity training for six weeks. So that in the first week, three interval repetitions were performed, in the second week, 5 interval repetitions, in the third week, 7 interval repetitions, and from the beginning of the fourth week to the end of the sixth week, nine interval repetitions were performed. Subjects in the supplement groups also consumed 200 mg of supplement per kilogram of body weight daily. After completing the training and supplementation period, the animals were anesthetized by injecting ketamine and xylazine, their soleus muscle was removed by open surgery, and after being transferred to a nitrogen tank, they were kept in a -80 freezer for western blotting. In order to answer the research questions, a one-way analysis of variance was used, and Tukey's post hoc test was used to check the differences. Results: The findings of the research showed that high-intensity interval training along with Q10 supplementation has no significant effect on the Nrf2 values of the soleus muscle of elderly rats (P > 0.05). However, high-intensity interval training with and without coenzyme Q10 supplementation, as well as coenzyme Q10 supplementation, only significantly decreased the NQO1 values of the soleus muscle of aged rats (P < 0.001).Conclusion: Considering the lack of effect of high-intensity interval training on Nrf2 and NQO1 reduction in elderly rats, in order to determine the mechanism of the effect of high-intensity interval training on antioxidant pathways, the conditions of the exercise program such as duration, intensity, repetition and exercise sets should be taken into consideration; It is also recommended to consider other standard dosages of coenzyme Q10 supplementation.
original article
Sports Physiology (General)
Ali Nosratihashi; Lotfali Bolboli; Sajjad Anoushirvani
Abstract
Background and Purpose: Resistance exercise with new training methods such as blood flow restriction, which is performed with lower intensities than the traditional method, can lead to different physiological responses. The purpose of this study was to investigate the effect of a period of upper body ...
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Background and Purpose: Resistance exercise with new training methods such as blood flow restriction, which is performed with lower intensities than the traditional method, can lead to different physiological responses. The purpose of this study was to investigate the effect of a period of upper body resistance exercise with blood flow restriction on the level of cortisol, testosterone and the ratio of testosterone to cortisol in male judo players.Materials and Methods: Thirty male judo players were divided into two groups of resistance training with and without blood flow restriction. The training program consisted of 6 weeks of resistance training, 3 sessions per week. Resistance exercise with blood flow restriction included performing barbell biceps curl exercise at an intensity corresponding to 30% of one repetition maximum (1-RM) with cuff pressure about 120 to 160 mm Hg (around the proximal area of the arm) based on the systolic pressure of each person. For the traditional resistance training group (without vascular occlusion), subjects performed biceps exercise at an intensity corresponding to 75% of 1-RM. To measure testosterone and cortisol, first blood sample (5ml) was taken before training from the antecubital vein of the right hand. The second blood was taken 48 hours after the last training session of 6th week, the third blood sample was taken 24 hours before the start of the second 6-week activity and the fourth sample was taken 48 hours after the last training session (after 12 weeks).Results: Between-group comparisons showed that cortisol (P=0.018), testosterone (P<0.001) and the ratio of testosterone to cortisol (P=0.001) were significantly different beuween two groups of resistance training with blood flow restriction and resistance training. Within-group comparisons showed that cortisol (P<0.001; d=1.76), testosterone (P<0.001; d=4.03) and the ratio of testosterone to cortisol (P<0.001; d=1.53) were increased significantly following resistance training with blood flow restriction and the percentage of changes were 38.48, 121.11 and 53.57%, respectively. Moreover, cortisol (P<0.001; d=1.27), testosterone (P<0.001; d=2.05) and the ratio of testosterone to cortisol (P=0.010; d=0.63) increased significantly in resistance training group by 25.35, 60.29 and 21.66 %, respectively.Conclusion: According to the results of the research, it could be concluded that both traditional resistance training and resistance training with blood flow restriction can lead to increases in testosterone, cortisol and the ratio of testosterone to cortisol. Furthermore, according to the size of the effect and percentage of differences, it can be mention that effectiveness of resistance training along with blood flow restriction is more pronounced than traditional resistance training.
Original Article
Sports Physiology (General)
Negar Jamili; Seyed Alireza Hosseini Kakhk; Roya Askari; Bahram Sadeghi
Abstract
AbstractBackground and objective: The effect of plyometric training on physical function is well known. The effect training with blood flow restriction has also been studied. But the effect of aquatic plyometric with blood flow restriction has not been studied. Therefore, the aim of this study was to ...
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AbstractBackground and objective: The effect of plyometric training on physical function is well known. The effect training with blood flow restriction has also been studied. But the effect of aquatic plyometric with blood flow restriction has not been studied. Therefore, the aim of this study was to investigate the effect of aquatic plyometric training with and without blood flow restriction on physical function of young active women.Materials and Methods: The study was a quasi-experimental study with a pre- post test. The participants are 30 young women aged 18 to 30 years were randomly allocated to three groups: aquatic plyometric training with blood flow restriction (n = 10), aquatic plyometric training without blood flow restriction (n = 10) and control (n = 10). Gpower software version 3.1.9.2 was used to determine the sample size, so that for the ANOVA test with repeated measurements, the size was 0.38 and the power of the test was 0.85 at the error level of 0.05, 30 people were determined. In order to measure the physical activity of the samples, Beck's physical activity questionnaire, which has 16 five-choice items, was used.One week before the start of the training program, two familiarization sessions with the research interventions (including plyometric exercises with BFR and without BFR and tests) are held for the subjects. plyometric training protocol including six weeks and three sessions each week for 60 minutes (with two to five sets and one to two minute rest). The intensity of training (number of sets and repetitions) was considered less in the group with blood flow restriction than the other group. Restriction of blood flow was applied by tightening the elastic band of the upper thigh. Physical function tests were taken before and after the training program. Data were analyzed RM- ANOVA statistical method with repeated measures and SPSS software. The statistical decision rule for the statistical test to reject or confirm the hypotheses was considered P≤0.05.Results: there was a Significant increase in fat percentage (p= 0/02, F= 4/04), anaerobic power (p= 0/05, F= 3/02), lower body power (p= 0/04, F= 3/36), speed (p= 0/05, F= 6/60) and maximum strength (p= 0/001, F= 11/95) in aquatic plyometric training with blood flow restriction showed improvements (p≤0.05). There was no significant difference between the group in other variables of physical function including weight, BMI, agility and upper body power (P> 0.05).Conclusion: According to the results of this study, aquatic plyometric traaining with blood flow restriction can be effective in improving fat percentage, anaerobic power, lower body power, speed and maximum strength of young active women.
Original Article
biochemistry and metabolism
Mehri Gholipour; Najme Rezaeian; Mohammad Karimi; Sadegh Cheragh-Birjandi
Abstract
Background and Purpose: Bile acids are known as key metabolic messengers during liver regeneration and the end product of cholesterol catabolism, which are important for nutrient absorption in the intestine. Recent studies describe bile acids as messenger molecules with diverse functions that have a ...
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Background and Purpose: Bile acids are known as key metabolic messengers during liver regeneration and the end product of cholesterol catabolism, which are important for nutrient absorption in the intestine. Recent studies describe bile acids as messenger molecules with diverse functions that have a wide range of receptors in the body. Due to these receptors, bile acids can modulate the rate of self-synthesis, lipid, and glucose and energy metabolism. The FXR-FGFR4-KLB signaling pathway and its role in the regulation of bile acid biosynthesis is one of the novel issues in cholesterol metabolism, especially in the condition of non-alcoholic fatty liver disease (NAFLD). This research was performed with the aims of study the effect of eight weeks of resistance training on liver bile acid (BA), beta klotho protein (KLB) and the expression of farnesoid X receptor (FXR), fibroblast growth factor 15 (FGF15) and fibroblast growth factor receptor 4 (FGFR4) in male rats with non-alcoholic fatty liver disease.Materials and Methods: In this experimental study, 16 Wistar male rats, with six-weeks age and an approximate weight of 120-160 grams, after induction of NAFLD conditions, with six weeks of high-fat diet were randomly divided into two equal groups (8 rats in each group), including; Control (C), resistance training (R).The training protocol of the R group includes climbing a 1-meter ladder with a 2-cm grid and an 85-degree incline, along with attaching cylinders containing weights to the rats' tails, with 50 to 75% of body weight and in an eight-week period with a frequency of five days per week. 48 hours after the last training session, the subjects were sacrificed and liver tissue were taken to evaluate the research variables. Data were analyzed by using independent t-test at a significance level of p<0.05. Results: Following eight weeks of resistance training, hepatic BA decreased significantly in R group compared to C group. (p=0.0001). Also, KLB protein levels (p=0.0001) and the expression of FXR (p=0.0001), FGF15 (p=0.0001), and FGFR4 (p=0.0001) genes were significantly higher in R group compared to C group. Conclusion: Non-alcoholic fatty liver is associated with a decrease in the expression of genes such as FXR, FGF15 and FGFR4, as well as a decrease in klotho protein, which results in a disturbance in cholesterol status and subsequent cell damage in the liver. The exercise intervention may have positive effect on the signaling pathway of FXR-FGFR4-KLB and its role in regulating the biosynthesis of bile acids and improve cholesterol metabolism in the body. It seems that resistance training has beneficial effects in improving this signaling pathway.
Original Article
Exercise Science
Mohsen Akbarpour; Safoora Sabagheyan rad; Narjes Chamani
Abstract
Purpose: The main objective of the research is to compare the effect of eight weeks of traditional resistance training and TRX on some oxidative and anti-oxidative indicators in women with type 2 diabetes.Introduction: Type 2 diabetes is a chronic non-communicable disease with a high global prevalence. ...
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Purpose: The main objective of the research is to compare the effect of eight weeks of traditional resistance training and TRX on some oxidative and anti-oxidative indicators in women with type 2 diabetes.Introduction: Type 2 diabetes is a chronic non-communicable disease with a high global prevalence. This disease is associated with modifiable risk factors such as inactivity and malnutrition, and is strongly related to cardiovascular diseases and cancer, the two main causes of death in the world. In recent years, a relationship between biomarkers of oxidative stress and type 2 diabetes has been found.Methods: The statistical sample of the research consisted of 30 women with type 2 diabetes aged 40-55 years who were purposefully selected and randomly divided into three groups: resistance training (N=10), TRX group (N=10), and control group (N=10). were placed. The training program consisted of 8 weeks and every week a resistance training session was performed with an intensity of 65% of the maximum repetitions and at the end of the eighth week it reached 80% of the maximum repetitions. During this period, the control group did not do any sports activities. Correlated T-test was used to examine group differences and covariance analysis using Bonferroni's post hoc test was used to examine inter-group differences.The training program consisted of 8 weeks and every week a resistance training session was performed with an intensity of 65% of the maximum repetitions and at the end of the eighth week it reached 80% of the maximum repetitions. During this period, the control group did not do any sports activities. Correlated T-test was used to examine group differences and covariance analysis using Bonferroni's post hoc test was used to examine inter-group differences.Results: After eight weeks of traditional resistance training and TRX, a significant increase in SOD and GPX levels was observed in the two experimental groups (p < 0.05). However, no significant difference was observed in the control group, and the amount of MDA after the test compared to the pre-test showed a significant decrease in both traditional and TRX resistance training groups. The results of intergroup analysis showed that there is no significant difference between the two groups of resistance training and TRX on SOD, GPX and MDA indices (P>0.05), while these two experimental groups were significant with the control group in the post-test phase.Conclusion: Based on the obtained results, it can be said that; Both training methods can have preventive effects on oxidative (SOD and GPX) and anti-oxidative (MDA) indicators in women with type 2 diabetes.
original article
biochemistry and metabolism
Javad Vakili; Vahid Sari-Sarraf; Sara Farajpour khazaei
Abstract
Introduction & Objective: There is a close relationship between liver mitochondrial dysfunction and the development of obesity and insulin resistance. As observed in type 2 diabetes, in conditions of insulin resistance, a decrease in insulin sensitivity of liver cells, skeletal muscle and fat cells ...
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Introduction & Objective: There is a close relationship between liver mitochondrial dysfunction and the development of obesity and insulin resistance. As observed in type 2 diabetes, in conditions of insulin resistance, a decrease in insulin sensitivity of liver cells, skeletal muscle and fat cells is observed. In recent decades, physical activity has become a key tool in controlling many diseases, including type 2 diabetes, and studies have shown that various exercise protocols reduce the prevalence and improve some It is effective in the metabolic functions of the liver. The aim of this study was to evaluate the effect of eight weeks of high intensity interval training on Parkin and Pink1 proteins in the liver tissue of type 2 diabetic rats.Materials and Methods: In an experimental study, 30 three-month-old adult male Wistar rats with a weight range (250-300 g) were randomly divided into four groups of 10 series including: healthy control (C: intraperitoneal injection of saline), Diabetic control (D: diabetic with high-fat diet combined with intraperitoneal injection of streptozotocin) and trained diabetic (D+T: diabetic with exercise) were divided. The training protocol includes running with an intensity of 85%-90% of the maximum speed in 6 to 12 two-minute intervals; It was 5 days a week for eight weeks. All rats, 48 hours after the last training session and after 12 to 14 hours of fasting, were anesthetized and operated by a trained specialist without pain. A method based on Western blotting was used to determine changes in the expression profile of Parkin and Pink1 proteins in the heart muscle tissue (left ventricle) of rats. The two-way analysis of variance and Bonferroni post hoc test were used to analyze the data.Results: Induction of diabetes (D) causes a 51% and 63% increase in Parkin and Pink1 proteins, respectively, although it is not statistically significant (P≥0.05). Also, exercise intervention caused a 45% and 38% decrease in Parkin and Pink1 in the trained diabetic group (D+T) compared to the diabetic group (D), but it was not significant (p≥0.05).Conclusion: According to the results, it can be stated that eight weeks of high intensity interval training (HIIT) is insufficient to observe a significant reduction of mitophagy in the liver tissue of diabetic rats. At the same time, due the partial changes of this study's indices, HIIT is a preventive measure against the abnormal increase of mitophagy due to type 2 diabetes. However, making a definite opinion about these indicators and how they are affected by different conditions depends on conducting further researches.
original article
Exercise Science
Eelahe Shadabnik; Farzad Nazem; Majid Jalili
Abstract
Background Purpose: Accurate measurement of cardiorespiratory fitness (VO2max) is very important in sports science. The gold standard for measuring cardiorespiratory fitness is the direct measurement of maximal oxygen uptake (VO2max) by the respiratory gas analysis device in the incremental exercise ...
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Background Purpose: Accurate measurement of cardiorespiratory fitness (VO2max) is very important in sports science. The gold standard for measuring cardiorespiratory fitness is the direct measurement of maximal oxygen uptake (VO2max) by the respiratory gas analysis device in the incremental exercise test (GXT). The direct measurement of VO2max using a respiratory gas analysis device cannot be very operational and comprehensive due to the high cost, time-consuming, need for an expert, and the possibility of some cardio-respiratory risks during the performance of an increasing exercise test. Estimating VO2max using equations based on heart rate index (HRindex) is one of the most widely used methods in sports fields, which can estimate an individual's VO2max without needing breath gas analysis. In heart rate index equations, two variables of resting and maximum heart rates are used to estimate VO2max. However, this requires that resting and maximal heart rates are measured accurately and with minimal error. The current research aims to evaluate the validity of VO2max equations based on heart rate index in adolescent boys.Material and Methods: In this cross-sectional study, one hundred and fifty-seven healthy adolescent boys (age: 14.92±1.35 year, BMI: 21.39 ± 4.5 kg/m2 and VO2max: 41.80 ± 6.67 ml/kg/min) from middle and high schools in Hamadan city participated voluntarily were Participated. First, the resting heart rate and body composition variables of the subjects were measured in a standard method. The subjects' VO2max and maximal heart rate were measured by the respiratory gas analysis method in the modified Bruce incremental exercise test (criterion method). Also, the subjects' VO2max was estimated using heart rate-index equations. Pearson correlation, pair sample t-test, and Bland & Altman agreement were used to evaluate the validity of heart rate index based VO2max equations.Results: A significant correlation was observed between the criterion method of VO2max and heart rate index-based VO2max equations (R=0.328, p<0.05). a significant difference (p<0.05) was observed between measured and heart rate index-based VO2max equations (Mean difference =3.34–5.45 ml/kg/min). So that both estimation equations lead to underestimation of VO2max by 11.36 ± 17.93% and 5.84 ± 16.39% respectively in healthy adolescent boys. Also, the Bland & Altman plot shows low agreement between measured and heart rate index-based VO2max equations.Conclusions: Heart rate index-based VO2max equations do not have sufficient validity in healthy adolescent boys. So, they significantly led to the underestimation of VO2max. Therefore, it is recommended to design heart rate index-based VO2max equations for healthy adolescent boys.
review article
cardiovascular and circulatory
Mohammad Javad Pourvaghar; Saeid reza Noorimofrad; Mousa Khalafi
Abstract
Background and Purpose: Vascular endothelial growth factor (VEGF) is the most important angiogenesis marker that may increase in response to exercise. However, the effect of acute exercise on this marker has been reported inconsistently. Therefore, the aim of this systematic review and meta-analysis ...
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Background and Purpose: Vascular endothelial growth factor (VEGF) is the most important angiogenesis marker that may increase in response to exercise. However, the effect of acute exercise on this marker has been reported inconsistently. Therefore, the aim of this systematic review and meta-analysis is to investigate the effect of acute exercise on circulating VEGF in adults. Materials and Methods: In order to extract original articles, a comprehensive search was conducted in the databases of PubMed, Scopus, Web of Science, SID, Magiran and Google Scholar until 2023 March 1 for studies of acute exercise on circulating levels of VEGF. The meta-analysis criteria included studies published in Persian and English language journals, studies with human subjects with an average age of more than 18 years, studies investigating the effect of acute exercise, and studies measuring serum or plasma VEGF levels. To determine the effect size, standardized mean differences (SMD) values and 95% confidence intervals (CIs) were calculated using CMA2 software. The level of heterogeneity was assessed using the I2 test and the publication bias was also assessed with Egger's test. Also, subgroup analysis was performed for health status (with chronic disease and healthy) and type of exercise (aerobic, resistance and high-intensity interval exercise).Results: In total, 27 articles (49 exercise interventions) including 704 subjects were included in the meta-analysis. The results of data analysis showed that acute exercise did not lead to significant changes in VEGF immediately after exercise compared to baseline [0.17, (CI: -0.05 to 0.40, p=0.14). The results of subgroup analysis based on the health status showed that exercise had no significant effect on VEGF in healthy subjects [SMD: 0.10, p=0.40], while it tended to significant increase of VEGF in patients [SMD: 0.30, p=0.05]. The results of the subgroup analysis based on the type of exercise also showed that resistance exercise [SMD: 0.58, p=0.008] leads to a increase and high-intensity interval exercise [SMD: 0.29, p=0.06] leads to a non-significant increase in VEGF, while the effect of aerobic exercise [SMD: 0.009, p=0.95] was not significant.Conclusion: In general, the findings of this meta-analysis show that the type of exercise plays an effective role in the response of VEGF to acute exercise. Resistance and high intensity interval exercise may lead to an increase in circulating VEGF immediately post exercise, while aerobic exercise does not have significant effects. Also, exercise may increase VEGF in people with metabolic-cardiovascular disease, while not being effective in people without chronic disease.
original article
cardiovascular and circulatory
Maryam Nazari; Vazgen Minasian; Silva Hovsepian
Abstract
Background and purpose: Obesity, especially central body obesity, is related to risk factors in cardiovascular diseases such as high blood pressure and hyperlipidemia. The aim of the present study was to investigate the relationship between blood pressure and serum levels of salusin-β, angiopoietin-like ...
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Background and purpose: Obesity, especially central body obesity, is related to risk factors in cardiovascular diseases such as high blood pressure and hyperlipidemia. The aim of the present study was to investigate the relationship between blood pressure and serum levels of salusin-β, angiopoietin-like protein 3, lipid profile and anthropometric indicators following eight weeks of interval exercises with different intensities among women with overweight/obesity.
Materials and methods: In this study, 30 inactive women were categorized into Three groups of 10 people as follows: control group (average age: 28.7 years ؛body mass index = 30.42 ±3.29 kg/m2), moderate-intensity interval training group: (average age: 30.2 years ؛body mass index = 31.19 ±3.75 kg/m2), and high-intensity interval training group: (average age: 28.9 years ؛body mass index = 30.17 ±3.83 kg/m2). The Subjects of training groups participated for eight weeks in the interval training of pedaling on a stationary bike with different intensities. Blood samples were taken 48 hours before the first training session to measure initial values and 48 hours after the last training session to measure changes and the serum levels of salusin-β, angiopoietin-like protein 3 were determined by ELISA method. Factorial ANOVA and Pearson's correlation coefficient tests were used to analyze the data.
Results: Findings related to correlation between variables showed a positive and significant relationship between blood pressure and angiopoietin-like protein 3, waist-hip ratio, salusin-β, waist circumference and an inverse significant relationship between blood pressure and high density lipoproteins .After eight weeks of interval training, The results of factorial analysis of variance show a significant decrease in the levels of angiopoietin-like protein 3, salusin-β, triglyceride, weight, waist circumference, Waist-stature ratio, body mass index, systolic blood pressure and a significant increase in the levels of high-density lipoproteins in exercise groups, but no significant changes were observed in the serum levels of low-density lipoproteins and values related to diastolic blood pressure and the Waist-hip ratio following exercise interventions.
Conclusion: In overweight and obese individuals, the anthropometric indicators as well as serum levels of salusin-β, angiopoietin-like protein 3 and some lipoproteins can be mentioned as an important parameter for risk assessment of cardiovascular diseases such as hypertension. However, there is a possibility that indicators such as Waist-hip ratio and waist circumference are better than body mass index and body weight for predicting the risk of high blood pressure. Interval training with sufficient intensity can be effective in increasing people's health by improving body composition and reducing some serum proteins related to high blood pressure.
original article
biochemistry and metabolism
Aylin Jafarzadeh; NAJME REZAEIAN
Abstract
Background and purpose: Steroid Receptor RNA Activator (SRA) is one of long non-coding RNA (LncRNA) playing a dual role glucose homeostasis and insulin resistance. Purpose of this study was to investigate the effect of six weeks of high intensity interval training on Adipose Tissue Levels of SRA and ...
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Background and purpose: Steroid Receptor RNA Activator (SRA) is one of long non-coding RNA (LncRNA) playing a dual role glucose homeostasis and insulin resistance. Purpose of this study was to investigate the effect of six weeks of high intensity interval training on Adipose Tissue Levels of SRA and Insulin Resistance Index in Diabetic Rats with High Fat Diet and Streptozotocin. Materials and Methods: Twenty male wistar rat (10-12 weeks old, 200-300 gr) selected and type 2 diabetes was induced by six weeks of high-fat diet and then streptozotocin injection. Afterwards, obese diabetic rats were randomly divided into experimental and control groups. The rats in the experimental group participated in six weeks of high intensity interval training of 40 seconds of running on a treadmill at velocity of 25-35 meter/minute with 2 minutes of active rest between each repetition consist of running at velocity of 10 meter/minute, 30 minutes per session and five sessions per week. All rats were dissected 48 hours after the last training session and adipose levels of SRA, serum levels of insulin and fasting blood sugar were evaluated using appropriate laboratory methods. Data analysis were done using independent and paired t-test and Pearson's correlation test at a significance level of less than 0.05. Results: Six weeks of high intensity interval training resulted in significant decreases in adipose tissue levels of Steroid Receptor RNA Activator (P=0.001) in addition to significant decreases in levels of insulin (P=0.000) and fasting blood glucose (P=0.000), insulin resistance index (P=0.000) and body weight (P=0.028) in the experimental compared to the control group. Furthermore, six weeks of high intensity interval training in experimental group caused in significant decreases in body weight in post- test compared to pre- test (P=0.000). However, according to the Pearson correlation test, there were no significant correlations between the changes in Steroid Receptor RNA Activator levels of adipose tissue following high intensity interval training and changes in none of the measured indicators (P>0.05). Conclusion: it seems that in addition to improve body composition, six weeks of high intensity interval training play a role in improving insulin resistance by decreasing the levels of SRA. Because the studies acknowledged the existence of a positive correlation between adipose tissue expression of steroid receptor RNA and anthropometric and metabolic indices such as body mass index, body fat percentage, insulin of serum and insulin resistance, and gene expression pattern of steroid receptor RNA in adipose tissue is mainly consistent with immune indicators, which are inherently pro-inflammatory; it seems necessary to conduct more studies to better understand the mechanism involved.
Original Article
Exercise Science
Reza Komijani; majid jalili; Farzad Nazem
Abstract
Background and Purpose: The maximal heart rate is a physiological index to control the intensity of physical activity in exercise and rehabilitation. Due to the practical problems of measuring maximal heart rate in strenuous exercise tests, this physiological index is estimated by regression equations. ...
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Background and Purpose: The maximal heart rate is a physiological index to control the intensity of physical activity in exercise and rehabilitation. Due to the practical problems of measuring maximal heart rate in strenuous exercise tests, this physiological index is estimated by regression equations. Most scientific sources have used the two equations of Fox (age - 220) and Tanka (208 -0.7 age) to estimate the maximal heart rate. Fox and Tanaka's equations were designed based on the data obtained from the adult population. Therefore, these two equations may not be highly accurate in the child and adolescent population. The purpose of this research is to evaluate the validity of Fox and Tanaka's equations in estimating the maximal heart rate of children and adolescent boys. Material and
Materials and Methods: In the present study, maximal heart rate was measured in 349 healthy boys aged 8 to 18 years in a direct method in a modified Bruce test on a treadmill equipped with a respiratory gas analyzer. In the following, the maximal heart rate was estimated using Fox and Tanaka equations. In order to validate the equations of Fox and Tanaka, the measured and estimated maximal heart rate in total sample and children and adolescent were compared with each other. For this purpose, Pearson's correlation, pair sample t-test, and Bland-Altman's agreement were used.
Results: As the age of the subjects increased, there was no noticeable change in the maximal heart rate of the boys. So, a weak negative correlation was observed between age and maximal heart rate (R = -0.198, p<0.05). A significant correlation was observed between the maximal heart rate measured by the standard method with Fox (R=0.198) and Tanaka (R=0.198) equations (P<0.05). However, there is a significant difference between the measured maximal heart rate and estimated maximal heart rate by Fox (mean difference = 5.23±6.32, equivalent to 2.7% of the mean maximal heart rate) and Tanaka (mean difference = 3.07±6.17, equivalent to -1.44 percent of mean of measured maximal heart rate) was observed (P<0.05). So, the Fox and Tanaka equations led to overestimation and underestimation of maximal heart rate, respectively. Also, the Bland-Altman diagram indicated a low agreement between the maximal heart rate equations of Fox and Tanaka compared to the standard method. Further, by dividing the subjects into two age groups, 8 to 13 years and 14 to 18 years, there was no change in the results. So, no significant correlation was observed between maximal heart rate of Fox and Tanaka equations with standard method (R = 0.028-0.094) (p<0.05). Also, a significant difference was observed between the standard maximal heart rate and the Fox and Tanaka equations (mean difference=- 3.55 -6.26 beats per minute) (P<0.05).
Conclusions: It seems that the Fox and Tanaka heart rate equations do not have sufficient validity in children and adolescent boys. However, in situations where we have to estimate the maximal heart rate, Tanaka's equation has a lower estimation error. According to the results of this research, it will be beneficial to design a native equation to estimate the maximal heart rate of Iranian children and adolescent boys.
original article
Sports Physiology (General)
Davar Rezaeimanesh
Abstract
Background and Purpose: Irisin is an exercise-stimulated hormone that affects white adipose tissue and brown adipose tissue. Based on conducted studies, physical activity increases the expression of proteins such as follistatin, which causes weight loss by increasing energy consumption and has an effect ...
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Background and Purpose: Irisin is an exercise-stimulated hormone that affects white adipose tissue and brown adipose tissue. Based on conducted studies, physical activity increases the expression of proteins such as follistatin, which causes weight loss by increasing energy consumption and has an effect on the index of insulin resistance. The present study aimed to investigate the response of plasma levels of irisin, follistatin, and insulin resistance index to two types of high-intensity interval training (HIIT) in overweight men.
Materials and Methods: For this purpose, 33 overweight men (mean age 22.9±2.11 years, weight 82.45±6.1 kg, body mass index 26.7±1.22 kg/m²) who could regularly attend physical activity sessions were selected and randomly divided into three groups: 30-s HIIT groups (HIIT-30), 60-s HIIT (HIIT-60), and control. The training protocol was performed three sessions per week for eight weeks. The HIIT-30 exercise program included eight sessions of 30-second activity with an intensity of 80-90% of the maximum heart rate with a two-minute break in the first four weeks, ten sessions were in the fifth and sixth weeks, and twelve sessions were in the seventh and eighth weeks. The HIIT-60 exercise program included four sessions of 60-second activity with an intensity of 80-90% of the maximum heart rate with a four-minute break in the first four weeks, five sessions were in the fifth and sixth weeks, and six sessions were in the seventh and eighth weeks. The control group did not attend any regular training program during the research. Blood samples were taken to measure levels of Irisin, follistatin, and determine the insulin resistance index. One-way analysis of variance (ANOVA) and paired t-test were utilized at a level of P<0.05 to compare means of parameters.
Results: The intragroup evaluation of the data showed that there is a significant difference between the pre-test and the post-test of the 30-s HIIT and 60-s HIIT group in irisin and follistatin variables (P<0.05). The results of ANOVA indicated that the 30-s HIIT and 60-s HIIT changed levels of irisin (P<0.05), follistatin (P<0.05), and insulin resistance index (P<0.05). The comparison of inter-group changes showed that there is no significant difference between the HIIT-30 group and the HIIT-60 group in terms of the effect on the research variables.
Conclusion: According to the research results, it can be concluded that, by increasing irisin and follistatin levels, the two methods of HIIT of 30 and 60 seconds can treat obesity and cause weight loss and also improve the index of insulin resistance in overweight men
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