نشریه فیزیولوژی ورزش و فعالیت بدنی
سال یازدهم شماره 2 (پاییز و زمستان 1397)

The purpose of this study was to investigate the effect of different Intensities of circuit resistance training on plasma neuregulin and leptin concentrations in young men. Forty-five healthy young men [21.55± 0.17 years old; height= 175.42± 0.88 cm, weight= 73.10±
1.63 Kg] were randomly divided into 5 groups (control, 20, 40, 60 and 80% 1RM). Men of training groups performed circuit resistance training 4 times a week with given intensities for 6 weeks. The blood sampling was conducted to determine the levels of neuregulin-1, leptin, insulin, and glucose before, and after 6 weeks. Data were analyzed using the analysis of covariance and paired T-test. The plasma neuregulin-1 (P= 0.0001), leptin (P= 0.009), and insulin (P=0.013) levels were significantly increased in the training groups compared with the control group while there were no significant differences between the glucose (P=0.27) level of groups. The results showed circular resistance training plays a significant role in promoting the performance of NRG-1 and leptin.

Bax and BCL-2 genes are important genes that involve in the intrinsic pathway of apoptosis. Although the effects of interval and intensive exercises on the mechanisms involved in the gaining processes are less considered. So, the aim of the present study was to investigate the effect of high-intensity interval training on the expression of pro and anti-apoptotic genes (Bax and BCL-2) in myocard in aged male mice. This experimental study was performed on twenty 24- months old C57BL/6 mice. Animals were randomly assigned to the control (n=10) and experimental groups (n=10). The experimental group performed high interval intensity training for four weeks (five sessions per week). At first, the interval training started at the intensity equal to 85 percent of maximum speed and in the continuation of interval training, 5 percent was added weekly and the last two weeks ended with 95 percent rate. Forty-eight hours after the last training session, myocardial muscle was removed. Bax and BCL-2 genes expression were investigated by SYBR-Green Real-time PCR analysis. The results of Real Time-PCR showed that the average relative expression of pro-apoptotic Bax gene was significantly lower in the experimental group than in the control group (0.618±0.022 vs. 1 unit; P<0.05). Also, the average relative expression of Anti-apoptotic Bcl2 gene expression was higher in the experimental group than in the control group (1.824±0.084 vs. 1 unit; P< 0.05). The results showed that high-intensity interval training by modifying the expression of pro and anti-apoptotic genes (Bax and BCL-2) may be effective in reducing apoptosis in cardiac tissue of aged mice.

Studies show that exercise has positive effects on the central nervous system and cognition. The brain-derived neurotrophic factor (BDNF) is an important factor affecting cognitive function and has been recently discussed in a bulk trend of efforts in the health context. Due to the inadequate information about the effects of aerobic training and detraining period on the attention and serum’s BDNF in sedentary girls, the aim of this study was to investigate the effect of 4 weeks of aerobic training on continuous attention, BDNF, and probable mechanisms of this effect (i.e. Neurotrophic factors) in sedentary girls. Twelve sedentary girls (mean age= 23.90±1.92), voluntarily participated in the study. They started their workout exercises under the aerobic protocol for four weeks. The PASAT test and blood sampling were conducted in three stages including pretest, after four weeks of training and after following four weeks of the detraining period. To analyze the data, repeated measures and Pearson's correlation coefficient were applied at a significance level of P≤0.05. The results showed that four weeks of aerobic training led to a significant increase in continuous attention (P<0.05). However, the serum BDNF levels were negatively correlated with aerobic training (P<0.05). Both of these factors were restored after following four weeks of detraining. Also, the correlation between changes in the continuous attention and expression of BDNF was not statistically significant (P=0.85). Generally, the findings indicated that physical activity can improve continuous attention and adaptation of serum’s BDNF. However, these adaptations were dissipated after detraining.

Psychological stresses induced by competition, can cause immune system alternations, which predisposes the athletes to infectious diseases more than common exercises. Therefore, the purpose of this study was to examine the effects of official sports competition on leucocyte, and subsets counts, immunoglobulin A (IgA), G (IgG), and cortisol levels in male karatekas. Ten male karatekas (aged: 22.9±2.6 yr, height 176.4±8.3 cm, and body mass index 21.2±1.5 kg/m2), acceded to final competition of Ilam province, were selected. Blood samples were collected before, immediately and 2 hours after the competition to measure the number of leukocytes, neutrophils, lymphocytes, monocytes, eosinophil’s counts and IgA, IgG and cortisol levels. The leucocyte (P=0.001), lymphocyte (P=0.001), and monocyte (P=0.003) counts were significantly increased immediately after the competition but returned to baseline 2h after the competition. Neutrophil and eosinophil counts did not change immediately and 2h after the competition (P>0.05). The serum levels of IgA (P=0.037) and IgG (P=0.04) were decreased significantly immediately after the competition and returned to baseline 2h after the competition. Also, the serum cortisol level was increased significantly immediately after the competition (P=0.0001) but decreased 2h later, compared to before (P=0.01) and immediately (P=0.001) after the competition results. Based on the findings of the present study, official competition can cause transient depression on humoral immunity in young male karatekas. It seems that 2h rest after the competition is sufficient for the recovery of leucocyte subset counts and immunoglobulin changing induced by competitions.

Exercises increase platelet activation and aggregation in patients with cardiovascular diseases especially at high intensities. The aim of the study was to investigate the effect of 8 weeks of high-intensity interval training on platelet activation and aggregation and phosphorylation of VASPser239 in the coronary heart patients. For this purpose, twenty CABG and PCI patients (≤ 3 months) participated voluntarily and were randomly divided into two groups; i.e. control (N=10) and interval training (N=10) groups. Anthropometric characteristics and peak oxygen consumption were recorded a week before the start. High-intensity interval training group patients participated in an 8 weeks exercise training program, three times a week. The interval training program consisted of a warm-up, 8 reps/ four min (exercise: 2min, active recovery: 2min, intensity: 90/ 30) and finally, cool down. Each session lasted 40 min. The training intensity was started 75/ 15% of the peak oxygen consumption but gradually increased during the first two weeks to reach 90/ 30% of peak oxygen consumption in the last two weeks. The control group did not participate in regular exercises during this period. Blood samples were taken before and 48h after the last exercise session and analyzed for platelet aggregation, CD62p expression, and phosphorylation of VASPser239. The dependent and independent t-tests were used for statistical analysis. A significant difference was observed between the two groups in the amount of decrease in platelet aggregation and CD62p expression in response to ADP (P <0.05). Also, the VASP phosphorylation at ser239 was increased significantly in response to NO in the interval training group (P<0.05). Eight weeks of high-intensity interval training led to the improvement in platelet activation and aggregation factors in coronary heart patients of this study. It seems that regular high-intensity exercise may improve platelet function, due to a decrease in CD62P expression and an increase in sensitivity to NO production by endothelial cells.

The aim of this study was to evaluate the effect of two methods of aerobic and resistance training on plasma levels of omentin-1, CRP and aerobic capacity of overweight and obese women. Twenty-two overweight and obese women volunteered to participate in this study. They were randomly assigned in two groups of aerobic (Mean age: 40.64±7.76y, BMI: 30.40±4.94 kg/m2, body fat percent: 27.31%±2.98) and resistance exercises (Mean age: 40.91±6.82y, BMI: 31.69±4.81 kg/ m2, body fat percent: 26.94%±2.99). The aerobic training program included jogging and running activities with 55%-75HRmax for 30-60 minutes, 3 sessions a week, and resistance training included a weight training program with 75% 1RM for 3 sets and 3 sessions per week for eight weeks. Blood samples were collected before interventions and 24 hours after the last training session in a fasting condition. The results showed eight weeks of aerobic and resistance training interventions caused significant decrease in C-reactive protein, and significant increase on Omentin-1 and aerobic capacity of both groups (p<0.001); but there were non-statistically significant differences between C-reactive protein, Omentin-1 levels and aerobic capacity of both groups (p>0.05). The results revealed the effectiveness of both aerobic and resistance training on C-reactive protein, Omentin-1 levels, and cardiorespiratory endurance of both groups. It seems that short term exercise interventions have similar effects on these metabolic indexes.

C1q/TNF5 is a new adipokine that plays an important role in the metabolism of glucose and lipids. High-intensity interval training (HIIT) is a form of interval training, alternating short periods of intense anaerobic exercise with the less-intense recovery period. The aim of this study was to evaluate the effect of eight weeks of HIIT training on serum levels of C1q/TNF5, insulin resistance, and fat percentage in overweight women. The research method was semi-experimental with pre-test and post-test design. 28 overweight and inactive women were randomly assigned to two equal groups, control group (age 30.142±3.526 and BMI 28.742±0.882 kg/m2) and HIIT group (age 29.928±2.758 years and BMI 28.147±1.126 kg/m2). The HIIT group performed interval running with the maximum speed, three times per week for eight weeks. Blood sampling was done 24 hours before and 36 hours after the training. The blood serum was used for the measurement of C1q/TNF5 level and insulin resistance. Data were analyzed by paired t-test and independent t-test (P<0.05). A significant reduction in serum levels of C1q/TNF5 (P=0.003), insulin (P=0.009), and body fat percentages (P=0.003) were observed after eight weeks of the HIIT training. However, fasting blood glucose and insulin resistance (P>0.05) remained with no significant changes. It seems that HIIT training can be a useful way to reduce overweight and obesity complication by decreasing the serum levels of C1q/TNF5 and insulin as well as the body fat percentage.

Post-activation potentiation (PAP) is a relatively new training technique that positively influence athletes’ performance. The purpose of this study was to determine the acute effects of different PAP warm-up protocols on anaerobic performance, and lactate changes in Talo female athletes. Ten elite Talo female athletes (age 19.9± 3.31, height160 ± 3.7 cm, weight 54.68± 5.18kg, body fat 13.3± 3.37%, Body mass index 21.19± 1.46) participated. They randomly performed one of the three following protocols in consecutive days: A. specific Wushu warm up (specific protocol); B. 2 sets × 2 repetitions back squat with 70%1RM (strength protocol); and C. 40 yard sprint with 0, 10, 20, and 30% of body weight (speed protocol). The RAST test was done 5 minutes after each warm-up protocol. Heart rate (for 10 seconds) and blood lactate (via lactometer) were recorded before and immediately after warm-up, as well as before and immediately after RAST test. For data analyzing, the repeated measures ANOVA and LSD post hoc was used. Results showed a significant difference among the mentioned 4 times of lactate measurement (P<0.001), while there was no significant difference among protocols in a given time (P>0.05). A significant difference between specific and the strength protocols (P=0.002) in case of minimum power, and strength and speed protocols (P=0.ی024) in regard to the fatigue index was observed. Both were in favor of strength protocol. There was no significant difference among the warm-up protocols on peak power and mean power (P>0.05), too. The type of the training performance determines the magnitude of PAP effects. Results indicated PAP probably wouldn’t have any efficacy in Talo athletes due to the glycolytic dominant system while probably PAP has more positive effects on speedy and power-explosive athletes.

Obesity is the cause of many diseases and the growth of adipose tissue is related to its vascular changes. Studies show that various exercises can affect vascular adipose tissue regulation. The purpose of the present research was to study the effects of high-intensity interval training (HIIT) and moderate intensity continues training (MICT) on fibroblast growth factor (FGF-2) gene expression in visceral and subcutaneous adipose tissues of male Wistar rats. In this experimental study, 24 male Wistar rat (Age 8 weeks and weighing 220-250 grams), as the study samples, were divided randomly to basal control, 8 weeks control, HIIT training, and MICT training groups. Exercise training groups practiced on rodent’s treadmill 5 days per week, for 8 weeks. In MICT groups, the duration and intensity of training protocol were 15 to 60 minutes and 50-75% of VO2max, respectively. In the HIIT group, rats run 4-8×1 min with 70-100% of VO2max and 1 min active recovery with 50-70% VO2max. Subcutaneous and visceral adipose tissue samples were removed 48 hours after the last training session. Real-Time PCR method used to assess FGF-2 gene expression. Results showed that after 8 weeks of MICT and HIIT training, FGF-2 gene expression in subcutaneous and visceral adipose tissues increased and decreased respectively, although these changes were not statistically significant (P>0.05). According to the results, it seems that despite the lack of significant effect of exercise on FGF-2 gene expression, the different responses of the subcutaneous and visceral fat tissues to exercise activity reflected different angiogenic activity. In general, several different angiogenic factors are involved in this process which needs more study.

Myogenesis plays an important role in the skeletal muscle reconstruction and growth. However, the impact of High-intensity Interval Training (HIIT) on the factors of this process is unknown. The purpose of this study was to investigate the effect of 8 weeks HIIT on myogenesis main factors, i.e. Myogenic Factor 5 (Myf5) and Myogenin in the rat's gastrocnemius muscle. In this experimental study, sixteen male Wistar rats (at age of 10 weeks, weight= 255 ± 25 gr) were randomly divided into two groups (control (n = 8) and HIIT (n = 8)). HIIT protocol was performed for 40 minutes, three days a week for eight weeks. 48 hours after the last training session, gastrocnemius muscle was extracted and MyF5 and myogenin gene expression were measured by Real Time-PCR. To analyze the data, independent T-test was used. Compared to the control group, MyF5 and myogenin gene expression significantly increased in the experimental group (P˂0.05). Additionally, gastrocnemius muscle weight in training group was significantly higher than the control group (P˂0.01). It seems that HIIT leads to a significant increase in the expression of MyF5, Myogenin, and gastrocnemius muscle weight in rats.