نشریه ورزش و علوم زیست حرکتی
سال چهاردهم شماره 2 (پیاپی 28، پاییز و زمستان 1401)

Cytokines released from skeletal muscle are involved in the control of muscle mass. Therefore, the aim of the present study was to investigate the effect of a period of resistance training with reduced blood flow on plasma levels of myostatin and IL-6 in martial arts young men.

The present study was a quasi-experimental study with pre-test and post-test. 20 young martial arts men aged 25 to 30 years and an average weight of 70 to 80 kg  were randomly assigned to two training groups with blood flow reduction (10 people) and the training group without blood flow reduction (10 people). A resistance training program with reduced blood flow was performed for four weeks. Myostatin and IL-6 concentrations were measured by ELISA One-way analysis of covariance was used for statistical analysis at the significance level of a = 0/05.

  The results of the present study showed that in the exercise group with decreased blood flow compared to the exercise group without decreased blood flow, the amount of myostatin decreased significantly (P=0.001) and the amount of IL-6 significantly increased (P=0.001).

Resistance training combined with reduced blood flow by reducing myostatin levels and increasing IL-6 levels can help improve anabolic conditions and muscle structure.

Vaspin is one of the peptide adipocytokines secreted from adipose tissue, which plays a role in the pathogenesis of obesity and related disorders. Vaspin has recently been identified as a new adipocytokine with the effects of increasing insulin sensitivity. There is little information about the effects of exercise on vaspin concentration. The present study has studied the effect of endurance training and HIIT on the plasma concentration of vaspin in obese male wistar rats.

The current research was of a randomized experimental type with a comparison design of two control and experimental groups. 30 rats (mean and standar deviation of weight 200±20 gr and age 8 weeks) were randomly divided into 3 groups: control group, endurance training, and HIIT training. All 3 groups included 10 rats.  For 12 weeks, experimental groups did exercises based on exercise programs -three days a week, while the control group had no exercise. Following 12 weeks training, plasma vaspin were measured. 36 hours after the last training session and 10 hours of fasting, the blood samples of rats of all groups were taken directlyfrom the heart after cutting the peritoneal region. The Kruskal-Wallis test was used to compare the average of three research groups and the U-ManWhitney test was used to compare the pairwise averages at a significance level of P≤ 0.05.

After 12 weeks of endurance and HIT training, Vaspin levels, in practice Group endurance and HIT compared with the control group significantly decreased (P=0.001). This study showed both types of endurance training and HIIT, significantly improve Vaspin levels.

According to the results of the present study, it can be stated that endurance training and HIIT can be considered as a solution to reduce fat tissue and adipocytokines, including vaspin and other pro-inflammatory factors.

As exercise training, had led to improvement of physical fitness and physiologic adaptations in body, the loss of physical fitness after cessation exercise, is not unexpected. Therefore, the aim of this study was to comparing 4 weeks of detraining after 12 weeks of regular exercise on composition anthropometrics indexes, speed, agility and muscle power of women volleyball players.

In this Quasi-experimental research, among the female volleyball players of Semnan city who were members of the super and the first division league, 24 people voluntarily chose and participated in the research. After 12 weeks of regular training and participating in season competitions and the following 4 weeks of detraining (competition season holiday and at the time as same as Nowruz holidays), was measurement of circumference of waist circumference, hips, legs, 20 meters run, Illinois, and Sargent's jump, respectively, were performed to measure the anthropometrics indexes, speed, agility, and muscle power of the subjects. Data analysis was performed using descriptive statistics and paired sample t-test at a significance level of p˂0.05.

The results of the present study showed that 4 weeks of detraining caused a significant decrease in the agility (P=0.001) and muscle power (P=0.005) of the subjects. The size of the circumference of the organs and the speed of the subjects were also observed to decrease, but it was not significant.

Based on the findings of the research, 4 weeks of detraining caused drop in the performance and anthropometrics indexes of female volleyball players. Therefore, attention to the detraining and designing programs suitable for the off-season in order to prevent the effects of detraining could greatly help coaches and athletes to maintain physical fitness due to training, and avoid the negative effects of detraining.

How to descend from a height is one of the most important questions that occupy the minds of climbers. In this study, we compared downhill running in two continuous and interval manner on delayed onset muscle soreness (DOMS), muscle damage and immune system indices in adolescent boys.

For this purpose, 20 healthy sedentary adolescent boys (16.4±1.03 years and BMI=20.06±2.6 kg/m2) distributed in two identical (anthropometrics and functional) groups and rapidly ascended to 3,000 m altitude by gondola, then  going downhill for a distance of 14 km in two continuous and interval styles. Immunological indices, hemoglobin, hematocrit, muscle injury (Lactate dehydrogenase and Creatine kinase) and DOMS were evaluated before, immediately, 24 and 48 hours later. Repeated measure ANOVA was used to statistical analyses. Significance level was set to less than 0.05

Immunological indices were not different between groups, but, the immune cells at 24 hours after activity decreased compared to pretest in continuous group. Creatine kinase and lactate dehydrogenase were not different between groups. These enzymes increased immediately after downhill running in both groups, but magnitude of changes in creatine kinase was more in continuous group. Also, DOMS in the continuous group was more than interval group.

The results showed that although the levels of the immune system indices and muscle damage were similar between groups, but, downhill running in a continuous style compared to the interval style causes suppression of the immune system and DOMS elevation in sedentary adolescent boys.

Different training frequencies can affect the peoples’ physical fitness in different ways. The Purpose of this study was investigated the effect two programs work with trampoline with number of different sessions and the same volumes on some of the physical and motor function factors in girls with mental retardation.

30 girls student mentally retarded (8 to 16 years, weight: 37.83±1.53 kg, BMI: 19.04±4.19 kg/m2 and with an IQ of 50 to 70) were selected and randomly divided into two experimental groups and one control group. One of the experimental groups performed trampoline three times a week for 7 weeks and the second experimental group performed trampoline two times a week for 10 weeks. Before and after the training period, physical and motor fitness tests, including endurance function, Cardiorespiratory fitness, static balance, dynamic balance, agility, coordination, muscle strength and explosive Power. The data were analyzed using ANOVA repeated measurements and Bonferron's post hoc test at significance level of P<0.05.

The results showed that both exercise programs in experimental groups compared with the control group improved static balance, dynamic balance, agility, coordination, explosive power and muscle strength, but no significant difference was observed between the two training programs. Endurance function and cardiorespiratory fitness were not significantly different between the three groups.

girls mentally retarded can probably use the trampoline training with frequency of three sessions per week for seven weeks to improve their physical and motor fitness indices.

Obesity is a condition known to disrupt the homeostasis of inflammatory markers. Therefore, the purpose of the present study was to investigate the effect of 8 weeks of combined endurance-resistance training with garlic supplement on the serum levels of hs-CRP, IL-6 and IL-10 in inactive overweight boys.

This study was conducted on 46 healthy inactive volunteer male (mean age: 19.51±1.88 years, weight: 77.05±7.07 kg, height: (164.25 ± 6.53 cm) were randomly divided into 4 groups: training-placebo, supplement, training- supplement and placebo. The groups daily consumed 250 mg of garlic. The training groups also performed three sessions per week for 8 weeks. Serum levels of hs-CRP, IL-6 and IL-10 were measured using ELISA kits. Data were analyzed using correlated t-test and ANCOVA. The significant level was set at P<0.05.

In the examination of the post-test between the groups, there was a significant difference between interleukin 10 levels (P=0.002, F=5.92), but no significant difference was found in the concentrations of interleukin-6 and hs-CRP (P=0/15, F=1.86; P=0.27, F=1.22). The results of Tukey's post hoc test showed that interleukin 10 levels were significantly different in the training -placebo groups with placebo (P=0.023) and supplement with placebo (P=0.003). In examining the post-test levels between the 3 groups, no significant difference was found in any of the investigated variables (P= 0.078, F=2.72; P= 0.15, F=1.86; P=0.27, F=1.22) (IL-10, IL-6 and hs-CRP variables, respectively).

The improvement of hs-CRP, IL-6 and IL-10 by performing combined training alone or with the consumption of garlic probably indicates the necessity of performing trainings in interventions to improve selected inflammatory indicators.

Creatine supplementation has been widely used among athletes. The use of resistance training along with dietary supplements are the most widely used methods that improve strength and increase muscle hypertrophy and improve performance in athletes. The aim of this study was to evaluate the effects of resistance training (RT) and supplementation of creatine hydrochloride on muscle strength and body composition in trained women.

In this quasi-experimental and applied study with pretest-posttest design 24 young trained randomly assigned to one of two groups: Group 1: RT with CrHCL supplementation (RT + CrHCL, n=12) and Group 2: RT with placebo (RT+PL, n=12). The participants performed 8 weeks of RT (70–85% one repetition maximum (1RM). 48 hours before and after the training period, muscle strength, body composition and upper body muscle hypertrophy and lower body muscle hypertrophy were measurements. To determine the difference between research variables mixed ANOVA test was used at a significance level of 0.05. 

Significant increases were observed for body weight, fat mass, fat free mass, skeletal muscle mass, upper body muscle hypertrophy and lower body muscle hypertrophy between pre and post-test in the RT + CrHCL group (P<0.05). In addition, percentage of body fat and fat mass was significantly decreased in the post-test in the RT + CrHCL group (P<0.05). The bench press and leg press strength changes in the RT + CrHCL group were significant compared to the RT+PL group (P<0.05, P=0.001, P=0.017). In other variables, despite the significantly increase and decreased in the post-test in the RT+CrHCL group, no significant differences were observed between the two groups (P>0.05).   

It seems that 8 weeks of the CrHCL supplementation as a new type of creatine with RT can have significant effects on muscle strength in young trained women.

Aging causes the decreased of muscle mass, strength, and or limited activity known as sarcopenia in the elderly. Therefore, the purpose of this study was to determine the effects of eight weeks of high-intensity interval and L-citrulline supplementation on serum CAF and neuromuscular indices in elderly men with sarcopenia.

In this randomized clinical trial, 41 elderly men with sarcopenia randomly divided into four groups: high-intensity interval training+placebo (HIIT), citrolin (CIT) and high-intensity interval training+citrolin (HIIT+CIT) and placebo (P). HIIT was performed for 8 weeks and 2 sessions per week that included 30 seconds cycling exercise on ergometer (intensity of 85-90% HR reserve). CIT supplement consumed in single 6 g-dose alternative day. Pre and post-training intervention, neuromuscular indices (muscle quality, chair sitting-standing time, timed up and go) were measured and blood sample (CAF) were taken. Repeated measures ANOVA and Bonferroni post hoc tests was used for data analysis.

Results showed that there was significant decrease for CAF and significant increase for muscle quality and sitting-standing time in HIIT+CIT and HIIT than P (P<0.05). Lean mass index and walking speed significantly improved in HIIT+CIT and HIIT than P (P<0.05).

In conclusion, HIIT with two sessions per week frequency improved neuromuscular indices in sarcopenic elderly men and therefore, can be considered an effective method to prevent or reduce sarcopenia.

Athletic performance is a complex phenotype that is determined by several environmental factors such as diet, exercise and social factors. Genetic factors may also contribute to the inter-individual differences in athletic performance. The aim of the current study is to investigate the frequencies of alleles of polymorphism of ACTN3 gene among Ardabilian adolescent beginner wrestlers.

The subjects in this research were 15 beginner teen wrestler boys (with 13.07±1.53 years old and 48.66±7.37 kg weight) from Ardabil city. The method of measuring ACTN3 gene polymorphism using polymerase chain reaction and direct DNA sequencing through saliva sample was determined and compared. The data were analyzed by goodness of fit chi-squared test at a significant level P<0.05 using SPSS 22 software.

The results showed that there was a significant difference in the frequencies of ACTN3 gene polymorphism (P<0.001). The relative frequencies of RR and RX genotypes were 80% (n=12) and 20% (n=3), respectively. Also, the relative frequencies of R and X alleles were 90% (n=27) and 10% (n= 3), respectively.

In general, the results showed the superiority of the R allele in ACTN3 gene polymorphism in the Ardabilian beginner teen wrestler boys. It seems that the evaluation of the frequencies of polymorphism of genes may be effective in choosing the right sports field in basic age classes.

Recovery is very important aspect of training. Desire for food intake is important at this time. The aim of the present study was to evaluate the response of glucose, insulin and appetite to the amount of carbohydrate consumption after intense intermittent exercise (HIIE).

Thirty-two female athletes (age 22.41±1.04 yrs and weight 56.77±2.41 kg) participated in this study were divided into two carbohydrate drink rate (1.2 g/kg) and (0.4 g/kg) groups. The HIIE consists of 8×3 min set at 80% HRmax. The initial speed was 6 km/h with a 1% gradient. Running speed was increased by 1 km/h with 3 min intervals. 90-s active recovery at 55% between repetitions was considered. The subjects consumed CD at 15 and 90 min after HIIE. Blood samples were taken before, immediately and 150 min after and appetite was measured by a visual analog scale [VAS] before, immediately, 15, 30, 60, 90 and 150 min after HIIE. Statistical data analysis was conducted by the repetitive multivariate analysis of variance and Pearson correlation coefficient (P<0.05).

Amount of carbohydrate intake leads to significant differences in desire for food 30 min after activity (P<0.05). 0.4 g/kg carbohydrate drink led to a lower desire for food (P<0.05). Glucose immediately after exercise into two groups was increased, but after 150 min in the 1.2 g/kg group was decreased (P<0.05).

According to the results, it seems that appetite decreased after HIIE and increased after carbohydrate consumption in both groups, which can be justified due to glucose absorption and improvement in insulin resistance.

Glucose absorption improves in the human body by IL-15 and related metabolic disorders in patients with metabolic syndrome (MS) may be affected by aerobic exercise. The aim of this study was to investigate the effect of an aerobic exercise session on interleukin-15 levels and metabolic risk factors.

In this study 20 men with MS were selected voluntarily and randomly divided into two control (n=10) and aerobic exercise (n=10) groups. The exercise program included 12weeks of aerobic exercise with 3 sessions per week and each session consisted of 45 minutes of exercise with an intensity of 60-70% of the maximal heart rate. Blood samples were taken from the subjects before and after the intervention of the exercise program to measure blood variables including IL-15, HDL, LDL, TG, TC, and blood glucose. The data were analyzed by independent and dependent sample t-tests at a significance level of 0.05.

There is a significant difference between the two groups in all variables. In the exercise group, in the post-test compared to the pre-test, the values of IL-15, HDL, and VO2peak significantly increased (P<0.05).  The values of BW, BMI, WC, MBP, TC, TG, LDL, FBS, and insulin resistance index had a significant decrease (P<0.05).

12 weeks of moderate- intensity aerobic exercise program can be suggested as a non-drug method to control metabolic risk factors in patients with metabolic syndrome.

Diabetes leads to defects in BDNF function and disturbances in CRP and IL-6 serum levels. The purpose of the study was to determine the effect of eight weeks of simultaneous endurance-resistance exercise on BDNF, CRP, and IL-6 serum levels in type1 diabetic male Wistar rats.

In this experimental study, 30 adults male Wistar rats (250-300 grams and aged six weeks) were randomly divided into three groups including two diabetic groups, diabetic exercise (n=10), diabetic control (n=10) and a non-diabetic group, healthy control (n=10). At the end of the eight-week-old, an amount of 55 mg/kg of body weight of streptozocin (STZ) was injected intraperitoneally, to make diabetic. The diabetic exercise group performed the eight weeks of combined exercises; 5 times per week (endurance exercise with 75% Vo2max on the treadmill and strength training including 15 times climbing the ladder). To measure the serum levels of BDNF, CRP, and IL-6, blood samples were taken. One-way ANOVA and post-hoc Bonferroni test were used to compare between-group and intra-group changes of BDNF, CRP, and IL-6. The significance level was P<0.05.

After eight weeks of endurance-resistance training, BDNF level significantly increased in the diabetic exercise group compared to the diabetic group (P=0.009). Whereas, it significantly decreased in the diabetic control group compared to the healthy control (P=0.0001). CRP levels significantly decreased in the diabetic exercise group compared to the diabetic group (P=0.008). However, it significantly increased the diabetic control group compared to the healthy control (P=0.0001). There was no significant change in IL-6 level (P=0.057).

It is recommended that diabetic people perform eight weeks of simultaneous endurance-resistance exercises to increase BDNF levels and reduce inflammation.