JOURNAL OF PRACTICAL STUDIES AT BIOSCIENCES IN SPORT
Year:2018 | Volume:6 | Issue:11|Papers Count:12

Background and Aim: There is disagreement about transmitting the effects and the kind of strength-power training for making optimal neuromuscular adaptations in soccer players. The aim of the present study was the effect of 12 strength-power training weeks with different loads on neuromuscular adaptations in college soccer players. Materials and Methods: In this Quasi-experimental study, 36 subjects from 4 universities were divided into 3 equal groups based on a random sampling. Strength-power training program were carried out for 12 weeks (3 sessions per week) for all groups. In stages of pre test and post test were taken electromayographic amplitude and mean power frequency of vastus lateralis and medialis muscles, lower body muscular strength, anaerobic power, explosivepeak and average power. Data were analyzed using analysis of covariance and LSD Post hoc of and paired t-test in significant level of p<0. 05. Results: The load of 80-90 % of 1RM caused a significant increases in vastus lateralis mean power frequency compared to the loads of 60-70 % and 70-80 % of 1RM (p=0/01 and p=0. 02 respectively). Also the load of 80-90 % of 1RM caused a significant increases in vastus lateralis (p=0/01 ) and medialis (p=0. 006), electromayographic amplitude and lower body muscular strength (p=0/01 ) compared to the load of 60-70 % of 1RM. The loads of 80-90 and 70-80% of 1RM caused a significant increases in lower body anaerobic power (p=0. 0001 and p=0. 02 respectively) compared to the load of 60-70 % of 1RM. Conclusion: It's advisable to use the load of 80-90 % of 1RM with high speed and low repetition in planning the strength-power training form taking optimum neuromuscular adaptations.

Background and Aim: One of the important issues of sport rehabilitation in individuals with overweight syndrome is increase muscular function and modulate responses of muscular pain subsequent physical activity with consumption of medicinal plants. Therefore, the aim of this study was to investigate the effects of non-linear resistance exercise and glycyrrhizic acid supplementation on muscle function and perceivedmuscular pain in overweight young men. Materials and Methods: In this semi-experimental trials, 32 subjects (mean age: 21. 99 ± 1. 46 years, and body mass index: 26. 86 ± 0. 64 kg/m2) voluntarily participated in this study and divided randomly into 4 equal (n=8) groups including non-linear resistance exercise+supplementation, supplementation, non-linear resistance exercise+placebo and control groups. The training program performed for 8 weeks and 3 sessions per week. The muscular performance indicators and perceived muscle pain were measured respectively by one repetition maximum and McGill pain perception scale, before and after 8 weeks. The repeated measures, two-way and one-way analysis of variance (ANOVA) and Pearson correlation coefficient test were used for extraction of results at p<0. 05. Results: The results showed that perceived muscular pain at intervals immediately, 24, 48 and 72 hours after the last training session decreased significantly than pre-test and control group (p=0. 0001); wherase muscular performance increased significantly than pre-test (p=0. 0001). Moreover, it is observed significant inverse relationship between perceived muscular pain with body mass index and lean body mass (p=0. 02). Conclusion: In order to attain desire and beneficial results, non-linear resistance exercise along with glycyrrhizic gcid supplementation can be placed as an important part of sports rehabilitation program in overweight individuals.

Background and Aim: Ischemia induces physiological alterations in neurons that lead to cell death. Evidence suggests that physical exercise have a neuroprotective effect and can protect the brain from ischemic injury. The aim of this study was to evaluate the effect of 4 weeks of endurance training on tumor necrosis factor alpha, Interleukin-6 and Interleukin-1 beta levels after cerebral ischemia-reperfusion in male rats. Materials and Methods: Twenty one male Wistar rats were randomly divided into three groups including control, exercise-ischemia and ischemia groups. Physical exercise group were trained 5 days a week for 4 weeks. Ischemia induced by occlusion both common carotid arteries for 20 minutes. The cytokines level was measured by the ELISA method. The data were analyzed by the one way-ANOVA and Scheffe’ s post hoc tests and the significance level was considered if p<0. 05. Results: Endurance exercise led to significant decreases in the levels of tumor necrosis factor alpha (p=0. 04), Interleukin-6 (p=0. 003) and Interleukin-1 beta (p=0. 004). Conclusion: Endurance exercise can protect hippocampus against ischemia-induced injuries by attenuation of ischemic-produced inflammation.

Background and Aim: According recent evidence, regular exercise training can reduce the chronic inflammation. The aim of this study was to investigate the effect of 8 weeks of endurance exercise training on serum levels of IL-10 and body composition of sedentary overweight women. Materials and Methods: Twenty tow middle aged overweight (BMI>25 kg/m2) and sedentary women were from Pardis city randomized divided into two groups including control (C) and exercise training (EX) groups. Endurance exercise training group participated in running exercise on a treadmill (three sessions per week) for 8 weeks, 20-30 min per session, at 50-70% their maximal reserve heart rate. Blood samples were collected in fasting state at 48 hours before starting training and 48 hours after last exercise session. IL-10 level were measured ELISA assay. Results were extracted by analysis of covariance (ANCOVA) method at significant level of p<0. 05. Results: Body fat percent (p=0. 002), BMI (p=0/01 ) and WHR (p=0. 04) of exercise group significantly decreased in compare to control group but there was no significant changes in IL-10 (p=0. 52) levels and fat-free mass (p=0. 11). Conclusion: Endurance exercise training can play important role in prevention of diseases-induced overweight by improvement of body composition; however it seems that more studies will be needed for obtaining the anti-inflammatory effects of such exercise.

Background and Aim: The effect of periodization has been confirmed on the training adaptations; but the most effective approach are not known well for strength and endurance development for a wide variety of populations; therefore, the aim of present study was to investigate the effect of linear periodized (LP) and Nonlinear periodized (NLP) resistance training on muscular strength and endurance in untrained adolescence girls. Materials and Methods: A number of 23 untrained adolescence girls were randomly assigned into 3 groups including control group, LP group, and NLP group. The linear model of periodization include a volume decrease and an intensity gradually increase as training progressive and the nonlinear model of periodization includes an increase and decrease of the intensity and volume training, respectively during cycles training. 48 hours before and after 8 weeks protocols, the upper and lower body muscular strength were assessed via 1RM leg press and bench press movements respectively, and lower and upper body muscular endurance were measured through push up and squat movement, respectively as well. The data was analyzed using ANCOVA test and the significance level was considered if p<0. 05. Results: Data analysis showed that LP and NLP significantly increased upper and lower body muscular strength, upper body muscular endurance (p<0. 001), lower body muscular endurance (p=0. 01 ), and decrease body fat percent (p=0. 04). In addition, LP led to more increase in lower body muscular strength (p=0. 04), and NLP led to more increase in upper body muscular endurance (p=0. 03), while there was no significant difference in explosive power (p=0. 07), upper body muscular strength (p=0. 88), lower body muscular endurance (p=0. 99) and body fat percent (p=0. 64) between LP and NLP groups (p>0. 05). Conclusion: Although muscular strength and endurance are improved by the LP and NLP models; the LP model is better training method to improve lower body muscular strength and NLP model is a more approach to improve upper body muscular endurance in untrained adolescence girls, although strength and endurance of muscles are improved in the result of LP and NLP models.

Background and Aim: Serotonin and dopamine are the effective monoamine neurotransmitters in controlling emotions and appetite. The purpose of this study was to investigate the effect of 8 weeks of selected yoga exercises on serum levels of serotonin and dopamine in non-athlete obese women. Materials and Methods: In this quasi-experimental research, 20 non-athlete obese women with body mass index equal or greater than 30 kg/m2 and age range 25-35 years old volunteered to participate in the study. The subjects were divided randomly into two equal groups including control (regular life) and experimental (yoga exercises) groups. The experimental group did 8 weeks selected yoga exercises, 3 sessions per week and each session lasted 60-75 minutes. Before and after intervention, blood samples were collected from cubital vein at 12 h. fasting state. Serum levels of serotonin and dopamine were determined using by ELISA method. Data were analyzed using the paired t-test and ANCOVA at the significant level of p<0. 05. Results: Eight weeks selected yoga exercises lead to significant increases in serum levels of serotonin (p=0. 02) and dopamine (p=0. 0001) in experimental group while they did not change significantly in the control group. Conclusion: It seems that yoga exercises may have positive effects on some neurotransmitters affecting appetite and food intake behaviors in obese women.

Background and Aim: Despite the importance of good physical fitness among military personnel, it is shown that obesity and over weight in the police and armed forces increased in recent years. The purpose of this study was to examine the effects of aerobic training and detraining on body composition, lipid profile and insulin resistance in over weight policeman. Materials and Methods: A sample of 40 healthy Guilan policeman with a mean age of 29. 8± 6. 3 y, weight: 87. 42± 6. 2 kg, height 175. 5± 6 cm and BMI: 28. 55± 4. 4 kg/m2 volunteered for this study. The subjects were divided into two groups including aerobic and control goups. Aerobic exercise program performed for 8 weeks, three days per week, with 65-75 maximal heart rate for 20-minutes in every session. Before and after performing of aerobic exercise program all variables (body composition, insulin, glucose and lipid profile) were measured. After the aerobic training protocol and testing for the second time, the subjects were prohibited from every exercise for 6 weeks. All measurements repeated again after 6 weeks of detraining and the data were collected. For extraction of the results it is applied the repeated measure of analysis of variance and Tukey post hoc tests. Results: Performing of 8 weeks of aerobic exercise induced significant improvement in the insulin resistance (p=0. 003), fat percentage (p=0. 001), body mass index (p=0. 004) and lipid profile improvement (p<0. 05); while all adaptations returned to the baseline after 6 weeks of detraining. Conclusion: Regular aerobic exercise can improvement cardiovascular risk factors in military personnel; however these positive effects will be attenuated if considered detraining.

Background and Aim: Adipose tissue is an endocrine tissue that produces more than 50 cytokines and other molecules. These substances participate in inflammatory and immune processes. The aim of this study was to investigate the interactive effects of exercise on bicycle ergometer and anti-inflammatory extract of nettle on some obesity-related inflammatory markers in overweight and obese women. Materials and Methods: A total of 46 women, overweight and obese BMI>25 kg /m2 and age range of 25-45 years, were selected purposefully and divided randomly into four groups: "exercise+nettle" (n=12, BMI=31. 28± 4. 83 kg/m2), "exercise± placebo" (n=12, BMI=30. 34± 3. 11 kg/m2), "nettle" (n=11, BMI=29. 66± 4. 22 kg/m2) and "placebo" (n=11, BMI=29. 79± 2. 63 kg/m2). Aerobic exercise was done for 8 weeks, 3 sessions per week, each session lasted 16 to 30 minutes at 55 to 75 percent of maximal reserve heart rate by pedaling on the bicycle ergometer. Participants in two groups of nettle consumption received daily 8 ml of hydroalcoholic extract of nettle; and the placebo was a combination of water and a similar color of the extract at a daily rate of 8 ml. Data were analyzed by Kolmogorov-Smirnov, ANOVA and paired sample t tests at the significant level of p≤ 0. 05. Results: The results showed that after 8 weeks of intervention, there were significant decreases in the amount of tumor necrosis factor-alpha in ''exercise + nettle'' (p=0. 005), "exercise + placebo" (p=0. 04), " and "nettle" groups (p=0. 02). Also, 8 weeks of intervention caused significant decreases in IL-6 in "exercise + nettle" (p=0. 03), "and "exercise + placebo" (p=0. 004) groups, while a significant increase was observed in the placebo group (p=0/01 ). Conclusion: Aerobic exercise on the bicycle ergometer as a non-invasive method and consumption of nettle extract as an herbal supplement can modulate inflammatory markers both alone and in combination in of overweight and obese individuals.

Background and Aim: Mentally retarded individuals have poor physical fitness and inappropriate body composition. The purpose of this study was investigate of effect of combined exercise training program on body composition and physical fitness in mentally retarded girls. Materials and Methods: twenty two subjects from a private rehabilitation center (age: 22-30 years, intelligence quotients= 50-70) were selected and randomly divided in to two experimental and control groups. The training protocol included strength and aerobic training, eight weeks, three sessions per week, and each session 90 minutes. Part of resistance training included training with elastic bands and weight bearing resistance exercise (with respect of overload) and aerobic training included walking, jogging and rhythmic activities. Before and after training protocol body composition, general strength and aerobic power were measured. Data were analyzed using dependent and independent sample t-tests on gain scores, employing the SPSS statistical package program. The test significance level was taken as p<0. 05. Results: There were no statistically significant differences in weight (t=0. 48, p=0. 63), BMI (t=1. 35, p=0. 19), lean body mass (t=-0. 23, p=0. 81), fat body mass (t=0. 91, p=0. 37), and VO2max in Mc Ardle step test (t=1. 7, p=0. 1) and shuttle run test (t=-1. 14, p=0. 26) between groups, whereas muscular strength significantly increased (t=-4. 56, p=0. 001) in training group. Conclusion: Combined resistance and aerobic training can improve muscular strength in mentally retarded girls, whereas probably have no significantly effect on body composition and aerobic power. There for, it is It suggested that exercise training program consider as a part of daily activities and curriculum in rehabilitation centers, and these training designe with longer duration and more intensity and consideration dietary regimen.

Background and Aim: Angiopoietin-like protein 4 (ANGPTL4) is one of novel regulators of lipid metabolism which has role in obesity related diseases such as cardiovascular diseases. Therefore the purpose of this study was to the effect of 12 weeks of endurance training on serum levels of ANGPTL4 and lipids profile in obese women aged 50-65 years. Materials and Methods: Eighteen sedentary postmenopausal obese women (BMI>30Kg/m2) randomly assigned into experimental (n=10) and control (n=8) groups. Subjects in experimental group participated in 12 weeks of endurance training (running on treadmill at intensity of 60-80% of maximal hear rate). Serum levels of ANGPTL4, lipids profile and body composition indices measured before and 24 hours after last training session. Statistical analysis was done by paired and independent t-test and Pearson correlation coefficient and p<0. 05 considered as significant level. Results: Paired t-test showed levels of ANGPTL4 (p=0. 04), triglyceride (p=0. 03), total colestrol (p=0. 01 ) and very-low-density lipoprotein (p=0. 01 ) significantly declined after 12 weeks of endurance training; however, with Independent t test no significant changes observed for none of blood factors between experimental and control groups (p>0. 05). According to Pearson correlation coefficient there were no correlations between primary levels and changes of ANGPTL4 levels and those of blood factors assessed (p>0. 05). However, significant correlation observed between ANGPTL4 changes and changes in waist circumference following 12 weeks of endurance training (p=0. 05). Conclusion: Endurance training has role in regulating serum levels of ANGPTL4 in sedentary postmenopausal obese women and through improving lipids profile decreases risk of cardiovascular disease.

Background and Aim: Interval training have tremendous effects on physiological aspects of athletic performance. Also there are wide range of findings reported about rheological essences of training. The present study was intended to investigate the effects of two different high intensity interval training (HIIT) regimens on rowing performance and compare it to traditional rowing training in elite male rowers. Materials and Methods: Thirty elite rowers who represented in Iran national rowing team in 2014 divided into incremental high intensity interval (INC) training (n=10), smooth-like high intensity interval (SMO) training (n=10) and traditional endurance (TRA) training (n=10) randomly (age: 22. 4± 3. 6 year, height: 187. 4± 5. 9 cm, weight: 83. 7± 8. 7 kg, body fat percent: 8. 7± 2. 3). Performance characters including VO2max, vRmax, TvRmax, HR and Lactate and also, hemorheological factors were assessed in pre-training. These factors also assessed after a period of 8-week interval training (2 times per week) as post-training. ANOVA was recruited to evaluate the significance level of the changes in 0. 05 level using SPSS 16. 0. Results: Significant positive increases in VO2max (p=0. 0001 and p=0. 03 respectively), vRmax (p=0. 02) and TvRmax of INC and SMO (p=0. 03 and p=0. 01 respectively) were observed. Also MPO improved in INC (p=0. 02) and SMO (p=0. 03). But no any significant change in rheological factors (RBC, Hct, Hb and HCM) was shown between three groups (p>0. 05). Conclusion: Both of interval training regimens improved performance characteristics of the rowers. Nevertheless, INC improves performance in lactate threshold more than SMO.

Background and Aim: Nowadays, cold-water immersion (CWI) has been established as a promising means to support recovery in high performance sports after highly intensive training bouts or competitions. There are many studies about effectiveness of acute CWI to support recovery after strenuous exercise, but the overall results seem to be conflicting. However, adaptational aspect has been widely neglected. Therefore, we analyzed the effects of immersion in cold and moderate water after resistance training on the some adaptations of strength training. Materials and Methods: In all, 32 male Sprague-Dawley rats (8-weeks) were assigned randomly into 4 equal groups including control (208. 50± 22. 50 g), resistance training (208. 87± 26. 70 g), resistance training + moderate water immersion (208. 37± 16. 30 g) and resistance training + cold water immersion (218. 75± 33. 20 g) groups. The resistance training consisted of climbing (5 reps/3 sets) a ladder (120 cm) carrying load (equal to a percent of body weight) suspended from the tail. At last set (during 6 minute), rats in immersion water groups, immersed within container consisted water with 27˚ C and 14˚ C respectively. This process repeated 3 times a day during 8 weeks. At the first and last session, ladder climbing strength maximal was measured. Immediately after euthanasia (24 h after final training session), the flexor hallucis longus (FHL) and soleus muscles and subcutaneous-inguinal fat tissue was exposed and weighed. The data was analyzed with the one-way ANOVA method and significance level considered if p<0. 05. Results: Results showed that subcutaneous-inguinal fat (p=0. 01 ), FHL and soleus weight (p=0. 01 ) and maximal strength of ladder climbing (p=0. 001) were significantly different in all studied group; so the best improvement was obvious at the resistance + moderate water immersion group. Conclusion: It is concluded that immersion in moderate water have a better impact on the strength training adaptations in rats.