JOURNAL OF PRACTICAL STUDIES AT BIOSCIENCES IN SPORT
Year:2020 | Volume:7 | Issue:14|Papers Count:12

Background and Aim: Today, finding the best recovery method for athletes is very important. The purpose of this study was to measure the effects of repeated sprint activities (RSA) and 12 minutes immersion (CWI) in cold water (14 ₒ C) immediately after performance of RSA on fatigue serum inflammatory biomarkers as interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α ) in active men. Materials and Methods: The research adopted a quasi-experimental method and the statistical population was 20-26 year-old active men. In this was 20 active males after performance of RSA randomly were divided into two groups as control passive recovery (PAS) and experimental (CWI) groups. Blood samples were taken from both groups, immediately before and 24 hours after immersion in cold water. For statistical analysis, the Wilcoxon and repeated measures ANOVA tests were used (p<0. 05). Results: The results showed that RSA training significantly increased the TNF-α and IL-6 (p=0. 02 & p=0. 0001 respectively). However, the CWI significantly decreased the levels of TNF-α (p=0. 006). Although, the CWI and PAS after RSA, could not prevent from increaseing in serum IL-6 levels, however in the cold water group, this increase was lower (p=0. 001). After sprint activity, CWI caused significant reduction in serum levels of TNF-α in 24 hours after CWI (p=0. 01), moreover, the CWI and PAS significantly decreased the levels of IL-6 after 24 hours of cold water recovery (p=0. 01). Conclusion: Cold water immersiom and also cold with a local reduction in permeability of blood vessels could limit or delay the accumulation of inflammatory factors.

Background and Aim: Previous studies have shown that regular aerobic exercise improves fertility. However, there were conflicting results regarding the effect of resistance training on fertility. The aim of this study was to investigate the effects of resistance training (RT) with two different volumes on some semen parameters and serum levels of sex hormones in male rats. Materials and Methods: Twenty-four male Wistar rats (157. 7± 7. 6 gr) were randomly divided into 3 groups; control, high volume RT, low volume RT (8 rats in each group). The resistance training program included climbing the ladder for 8 weeks (3 days/week, every other day). Body weight, serum concentrations of testosterone (Ts), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured as well as the number and total sperm motility was calculated. Data were analyzed using one-way ANOVA and Bonferroni post hoc tests at the significant level of p<0. 05. Results: After 8 weeks of resistance training serum levels of LH in high volume RT group were lower compared with control group (p=0. 03). Higher levels of FSH in low volume RT group was found compared with high volume RT group (p=0. 009). There were no significant differences between groups in serum levels of testosterone, body weight values, number and total sperm motility (p>0. 05). Conclusion: According to these results, it seems that a disproportionate increase in resistance training volume can lead to decrease the levels of some sex hormones. Therefore, it may lead to disruption of the spermatogenesis.

Background and Aim: Resistance training (RT) is the most effective strategy to prevent age-related muscle wasting and weakness, because it promotes muscle strength and function. As the loss of muscle mass contributes to sarcopenia, the effects of RT on hypertrophy and its myogenic processes is controversial in old age. The purpose of this study was to examine the effects of RT on strength, mass and protein level of myogenin in gastrocnemius muscle of elderly rats. Materials and Methods: Sixteen elderly male Sprague-Dawley rats (24-month age) divided equally into two groups (control and RT). RT group underwent 8 weeks (3-days/week) of resistance training by climbing a wooden ladder with weights attached to their tails. Fourty eight hours after last session, isometric force, muscle wet mass and protein level of myogenin of gastrocnemius muscle were measured in both groups. For statistical analysis, independent sample t-test was used with a significance level of p<0. 05. Results: Absolute and relative (to body mass) isometric force of RT group were significantly greater than those in control group (p>0. 05). There was not any significant difference in wet muscle mass between groups. Western blot analysis of muscle tissue also showed that the levels of myogenin did not significantly differ between two groups (p>0. 05). Conclusion: Force production capacity and muscle quality (force to muscle mass ratio) were increased following resistance training in elderly rats through events are likely caused by neuromuscular adaptations. Additionally, the results suggest that increase in strength after resistance training in aged rats can not be explained in terms of the changing in muscle mass and myogenin expression values.

Background and Aim: The reduction of relaxin in menopause is one of the factors that cause physiological changes in women. Due to the lack of information about the effect of exercise training on the concentration of relaxin, the aim of this research was to study the effect of different intensities of resistance and aerobic training on serum relaxin levels in ovariectomized rat. Materials and Methods: In this experimental study, 60 female rats average weight 230 ± 10 gr were randomly assigned into 6 groups of 10, including: ovariectomy, ovariectomy +high intensity resistance training, ovariectomy + low intensity resistance training, ovariectomy + intense intermittent swimming training, ovariectomy + continuous swimming training and sham groups. First, the animals became ovariectomized and after a week, the rats in the exercise group performed selected training 3 sessions per week for 8 weeks. Afterwards, the levels of serum relaxin were measured by ELISA method. Data analysis was performed using one-way ANOVA test and the significant level was set at p<0. 05. Results: Serum relaxin concentration showed significant increases after 8 weeks of training as compared to the other groups as: control group or sham group (p=0. 0001), intensive resistance training group (p=0. 0001) and intensive swimming training exercise group (p=0. 002), however, no significant changes were observed in the continuous swimming training group (p=0. 10) and low intensity resistance training group (p=0. 43). Conclusion: Relaxin showed positive effects on various tissues of the body, this hormone decreases during menopause, but with high intensity exercise, the concentration of this hormone will increase.

Background and Aim: Growth associated protein 43 (GAP-43) and Adenylyl cyclase-associated protein 1 (CAP-1) are related to nerve cells restorations. But the role of physical exercise on these two proteins in cerebellum has not been clarified yet. The purpose of present study was investigating the influence of six weeks endurance exercise training on gene expression of GAP-43 and CAP-1 in cerebellar tissue of male Wistar rats. Materials and Methods: Twenty healthy male Wistar rats were selected and divided into two groups of including experimental (n=10) and control (n=10). Experimental group performed aerobic exercise, five days per week for six weeks with the speed of 11-18 m/min for 10-30 minutes. Control group did not have any exercise training program. Real time-PCR and 2-Δ Δ CT were used for biochemistry analysis. Statistical test of Kolmogorov-Smirnov was used for evaluating the data normality, and cosidering the violation of normal distribution, U Mann Whitney test was applied for comparing the groups. Results: Gene expression of GAP-43 (p=0. 002) and CAP-1 (p=0. 002) proteins increased significantly in the experimental compared to control group. Conclusion: Given the important role of GAP-43 and CAP-1 proteins in improving the nervous syetem, it seems that endurance exercise training can play a key role as a non-invasive method in increasing the gene expression of the proteins in cerebellum and so recovering and regeneration of cells and improving cerebelluar function.

The CGT sport supplement is combined of three supplements including creatine, glutamine and taurine that respectively formed 50, 30 and 20 percent of the total content of supplementation. The aim of this study was to investigate the effect of CGT supplementation on response muscle and liver damage markers (creatine kinase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase) to high intensity interval exercise (HIIE) in trained men. Materials and Methods: Nineteen trained men (mean age: 21. 82± 0. 73 years; BMI: 22. 35± 1. 51 kg/m2; fat percentage: 8. 47± 2. 36) were randomly divided into two groups as CGT supplementation (n=9) and placebo (n=10). Supplementation group consumed CGT for 2 weeks up to 12 grams per day and placebo group consumed starch powder at same dose. Both groups performed HIIE protocol during pre and post-supplementation that contains the sequences. Blood samples were taken in 6 steps included before, immediately and 2 hours after the first (pre-test) and second (post-test) HIIE protocol. The data were analyzed using repeated measures ANOVA, Bonferron's post hoc test and independent t-test at the significant level of p<0. 05. Results: Creatine kinase and lactate dehydrogenase levels significantly increased immediately and two hours after the exercise in both supplement and placebo groups (p ˂ 0. 05). But there was no significant changes in alanine aminotransferase and aspartate aminotransferase levels (p>0. 05). CGT significantly decreased response of creatine kinase and lactate dehydrogenase to HIIE immediately and 2 hours after the activity (p˂ 0. 05). However, CGT no significantly affected by changes in alanine aminotransferase and aspartate aminotransferase immediately and 2 hours after HIIE (p>0. 05). Conclusion: Short-term CGT supplementation could prevents muscle damage induced by high intensity interval exercise.

Background and Aim: There are strong evidences that exposure to hyperoxia improves performance during continuous exercise with positive effect on recovery. The aim of this study was to investigate the effect of inhaling oxygen during recovery on lactate response, blood PH and bicarbonate in trained young swimmers. Materials and Methods: In this semi-experimental study, 20 trained swimmers (20-28 years) were randomly divided into two groups including experimental (n=10) and control (n=10) groups. After warm-up, subjects performed front crawl swim up to 80 to 90 percent of record achieved during the 12-minutes and 1: 30 minutes recovery time in the pool. Protocol of oxygen inhalation was including oxygen inhalation at a concentration of 40% and 10 liters per minute, which was used as supplemented by the mask attached to the cylinder in recovery stage (rest 1: 30 min). The control group performed recovery stage by inactive manner. Fasting blood samples were taken before and after training from vein arm. For extraction of results, it is applied independent and paired t-tests at the significant level of p>0. 05 using the SPSS software. Results: The results showed that mean blood lactate, PH and bicarbonate of swimmers had a significant differences in before and after of training in the participated groups (p=0. 001); and lactate concentration of post training was significantly lower (p=0. 003) in the experimental group than control one. Moreover, mean PH (p=0. 003) and bicarbonate (p=0. 0001) concentration in post training were significantly higher in experimental group than control group. Conclusion: According to the findings, it seems that oxygen inhalation is effective during high-intensity exercise on blood lactate, PH and bicarbonate and it can be considered as an effective method for physiological recovery during exercise training.

Background and Aim: Previous studies have shown that brain-derived neurotrophic factor (BDNF) plays a vital role to induce the beneficial effects of exercise on the brain, especially the hippocampus. However, signaling pathways related to increasing BDNF induced by forced exercise in hippocampus not well known. Therefore, the purpose of current study was to investigate the effect of 8-week of low-intensity forced treadmill training on genes expression of peroxisome proliferator activated receptor-gamma co-activator 1-alpha (PGC-1α ), fibronectin type III domain containing 5 (FNDC5) and BDNF in hippocampus of male rats. Materials and Methods: Eighteen male Wistar rats were randomly divided into 3 groups including control (n=6), sham (n=6) and forced training (n=6). Animals in the training group performed 8 weeks of forced training (5 sessions per week) with low-intensity (speed: 15 m/min) on the treadmill. Twenty-four hours after last session of exercise, rats were decapitated and the hippocampus were carefully removed and rapidly frozen in liquid nitrogen, and finally stored at-80° C for further analysis. Real-Time-PCR method was used to measure the expression of genes in the hippocampus. Data were analyzed by one way ANOVA and Tukey post hoc test at the significant level of p<0. 05. Results: The results showed that mRNA levels of PGC-1α (p<0. 003), FNDC5 (p<0. 006) and BDNF (p<0. 02) in the forced training group were significantly higher than the control group. However, there was no significant difference in the mRNA levels of genes between the sham and control groups (p>0. 05). Conclusion: It seems that the low-intensity forced training, likely through a PGC-1α-dependent signaling pathway, leads to increasing expression of FNDC5 and as a result causes increasing the expression of BDNF. Thus, this type of exercise training can be used as induction of beneficial effects of exercise on the hippocampus.

Background and Aim: The purpose of this study was to investigate the role of aerobic training in protein expression of stromal cell-derived factor-alpha (SDF-1/CXCR4) and cardiomyocyte apoptosis following experimental myocardial infarction in male rats. Materials and Methods: Twenty six male rats (weight 235 ± 5 kg) were divided into healthy (sham), control, aerobic training and basic groups. To induce myocardial infarction subcutaneous injection of isoprenaline (150 mg/kg) on two consecutive days with an interval of 24 hours was used. Aerobic training group started training program 48 hours after induction of myocardial infarction. Training program include 4 weeks, 5 sessions per week of running on a treadmill (speed: 10-16 m/minute, Duration: 10-50 minutes, Slope: 5 degree). To study the protein expression and apoptosis, immunohistochemistry (IHC) and TUNNEL staining was used respectively. Data were analyzed using one-way ANOVA and Scheffe tests significant level was set as p<0. 05. Results: The results showed that injection of isoprenaline induced apoptosis and increased protein expression of SDF-1/CXCR4 and its receptor in infarcted rat hearts (p<0. 05). The results also showed that there was significant difference (p<0. 001) in the number of apoptotic cells between training and control group, but in terms of SDF-1/CXCR4 protein expression no significant difference was observed between two groups. Conclusion: Overall results showed that aerobic training after myocardial infarction can reduce the apoptosis of cardiomyocyte, but did not show any significant effect on protein expression of signaling pathways involved in angiogenesis such as SDF-1/CXCR4.

Background and Aim: Obesity and overweight in children and adolescence is very important. So, the aim of this study was to investigate the effects of 10 weeks of concurrent training on chemerin, irisin, insulin resistance and lipid profile in overweight children girls. Materials and Methods: Twenty-four overweight children girls (mean age=11. 23± 0. 62 y. and body mass index=27. 97± 0. 48 kg/m2) was divided into control (n=12) and concurrent training (n=12) groups. Training group underwent concurrent training for 10 weeks while control group performed daily activity. Chemerin, irisin, insulin resistance, total cholesterol, triglyceride, low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C) cholesterol (TC) were measured before and after study protocol. It is applied the ANCOVA test for statistical analysis at the significant level of p<0. 05. Results: Ten weeks of concurrent training significantly decreased level of chemerin, insulin resistance, cholesterol, triglyceride and LDL-C (p<0. 001); however, irisin, glucose and HDL-C concentration didn’ t affect by concurrent training (p=0. 18, p=0. 37, p=0. 06 respectively). Conclusion: Concurrent training could suggest as part of exercise training in overweight children girls and it may be an alternative training for traditional aerobic training.

Background and Aim Adipokines are involved in obesity-related illnesses and may be an indicatior of increase the risk of cardiovascular disease The aim of this study was to evaluate the effect of speed and endurance exercises training and a period of detraining on the serum levels of nesfatin-1, lipid profile, body fat percent, and body mass index (BMI) in non-athlete healthy men. Materials and Methods: Thirty-nine non-athletic male students were randomly divided into three equal groups (n=13) including speed training, endurance training, and control groups. Endurance training exercised up to 60-85 VO2max and speed training carried out up to 80-100 VO2max in 10 weeks, 3 sessions per week which followed by 4 weeks of detraining. Blood samples were taken after 12-hour fasting state under similar conditions. Serum levels of dependent variables were measured by commercial kits. It is applied the Shapiro-Wilk, repeated measure of ANOVA, one-way of ANOVA and least significant difference (LSD) tests for extraction of results at the significant level of p<0. 05. Results: There were no significant differnces between groups after 8 weeks of intervention (p<0. 05). While fat percent decreased significantly (p>0. 05) after endurance training; total cholesterol or triglyceride decreased and high density lipoprotein cholesterol increased significantly (p>0. 05) after speed training. On the other hand, we did not observe siginificant changes after 4 weeks of detraining (p<0. 05). Conclusion: With attention to the improvement of lipid characteristics after speed training, this type of exercise may have more effective role in the cardiovascular problems.

Background and Aim: Green tea extract has been suggested as an effective antioxidant to reduce the oxidative stress following resistance exercise. The purpose of this study was to investigate the acute effect of green tea extract supplementation on the oxidative and antioxidant indices after resistance exercise at moderate and high intensities in trained men. Materials and Methods: Eleven male resistance-trained wrestlers participated in a double-blind randomized placebo-controlled crossover design, including four periods of 1-week treatment with placebo and green tea extract (900 mg daily). The participants performed two medium-intensity resistance and two high-intensity resistance training, which were separated with 2-weks washout periods. The high-intensity exercise sessions included six exercises with six sets and four repetitions with 90% of 1RM, and the medium-intensity exercise sessions included six exercises with three sets and 10 repetitions with 70% of 1RM. Blood sampling conducted before and after the resistance training sessions to measure the oxidative and antioxidant indices. Regarding the non-normal distribution of data, the Kruskal-Wallis test were used for statistical analysis and the significance level was set at (p>0. 05). Results: No significant differences was observed between using green tea supplementation or placebo for the levels of malondialdehyde, total antioxidant capacity or superoxide dismutase, neither with high nor with medium intensity exercise sessions. Conclusion: Green tea supplementation for one week has no significant effect on oxidative and antioxidant indices after medium or high intensity resistance exercise sessions in male wrestlers.