SPORT PHYSIOLOGY (RESEARCH ON SPORT SCIENCE)
Year:2020 | Volume:12 | Issue:45|Papers Count:8

One of the major aging mechanism is telomere shortening that affected by factors such as telomerase and SIRT6. Exercise may have effective role in delaying aging and increase telomerase enzyme activity. However, these mechanisms are unknown. In this context, the aim of present study was to determine the effect of eight weeks high intensity interval training (HIIT) on serum levels of telomerase enzyme and SIRT6 protein in aged men. For this purpose, twenty aged men with average age of 63± 8 years, 71. 03± 5. 78 kg, body mass index 24. 49± 3. 25 kg/m2 and height 170. 79± 5/92 cm assigned into two control and HIIT groups. Subjects in HIIT group began the sprint training program with intensity of 90% reserve heart rate with three sets and three repetitions, and finally reached to five sets and six repetitions, but intensity maintained. Training program perform three time in week for eight weeks. At the end of training period, blood samples collected and experimental factors measured with Elisa method. for data analyze, covariance analysis and dependent t test used. Results of present study represent significant increase in SIRT6 protein and telomerase enzyme in HIIT group than to control group. Therefor respect to downregulation of telomerase activity and SIRT6 protein with aging, exercise training can be effective in compensate this decrease and delaying aging, and effectiveness pathway of exercise training in aged people can be partly related to increase in mentioned factors (telomerase enzyme and SIRT6 protein).

The present research aims to examine the effect of aerobic exercise with medium and high intensity on the gene expression of Bax and Bcl-2 markers in rat myocard after ischemicreperfusion by isoprenaline. 26 male Wistar rats were used weighing approximately 225. 25± 25. 25 g with two to three months old; Then pilot study with stroke group (n = 7) and control Group (n = 7) was knock to examine of isopernalin induced-infarct and the infarct of left ventricle were confirmed in isopernalin into normal groups used Massontrichrom teqnique. Then rats were divided into three groups to Measure gene expression: control (n=4), aerobic exercise with middle (n=4) and many intensity (n=4). The rats in research group were introduced to treadmill for a week, then the rats were exposed medium and high intensity aerobic training with frequency of three times weekly for one month. After two days of rest, rats were injected with isoprenaline within 24 hours; but control group were injected only with isopernaline in the end of one month. The formula 2-Δ Δ ct were used to measure the gene expression of BAX and BCL2, and independent ttest was used to compare the two groups of stroke and control in the pilot study and ANOVA were used to compare the groups. The results of study showed that aerobic exercise with medium and high intensity could reduce and increase the gene expression of BAX and BCL2, but these changes were not significant. Therefore, it seems that this intensity and period of training cannot active anti-apoptotic routes of exercise to minimize the effects of stroke.

The aim of this study was to compare the effects of drinking skim milk, soy milk, and water on fluid balance, rehydration and time to exhaustion during aerobic exercise. Eight trained females (age 21. 37± 0. 71 years, BMI 22. 06± 1. 42 Kg. m-2, VO2max 43. 09± 1. 83 ml. kg-1. min-1) randomly assigned. The subjects ran on a treadmill at 75% of maximum heart rate for 20 minutes. This process continued for each subject until approximately 1. 8± 0. 17% of reduction in body weight. Following that, subjects consumed one of the drinks randomized crossover design. The amount of consumed liquid was about 150% of the lost weight. Urine volume and urine specific gravity were measured after collecting urine samples. After the end of tree hours recovery, Bruce protocol was performed to evaluate exercise performance. The total volume of urine was significantly reduced in both milk and soy milk trials compared to water trial (P<0. 05). Furthermore, the net fluid balance in these two trials was significantly positive compared to water trial (P<0. 05) and the time to exhaustion was also longer than water trial (P<0. 05). However, there was no significant difference between these two trials, milk and soy milk, in these variables (P>0. 05). Therefore, drinking milk and soy milk led to better rehydration and fluid balance after exercise, which is associated with improved exercise performance.

Although the metabolism of blood lipids has been widely considered in studies, lipid metabolism in the brain has attracted more attention in recent years due to its association with some neurological disorders. Recent studies have shown that a number of risk factors for early onset of Alzheimer's are associated with cholesterol metabolism. Therefore, the purpose of this study was to investigate the effect of eight weeks of aerobic training on some factors involved in the metabolism of cholesterol in the hippocampus and its role in improving the cognitive function of male Wistar rats. The subjects of this study were 26 adult male Wistar 8 weeks old (weight 195 ± 20 g). At first, they were randomly divided into two groups: exercise (training on treadmill, 5 days a week for 8 weeks) (13 rats) and control (13 rats). After 8 weeks, the rats in each group were randomly assigned to two other subgroups: (7 rats: behavioral test, 5 rats were sacrificed). The results of one-way ANOVA of Morris water maze showed a significant improvement in learning (P<0. 05) and memory (P<0. 05) in the exercise group compared to the control group. Also, the results of one-way ANOVA showed a significant increase in the expression of mRNA APOE (P<0. 05) and ABCA1 (P<0. 05) and no significant difference in the level of Aβ 1-42 (P>0. 05) in the hippocampus in exercise group compared to the control group. Therefore, aerobic training by a significant increase in the expression of mRNA APOE and ABCA1, which are the main factors of lipid metabolism in the brain and which are involved in the pathology of Alzheimer's disease, can be consistent with improving cognitive function as an effective way of preventing of Alzheimer's disease.

Resistance training with HMB supplement helps preserving the body mass and, that is why, it is extensively practiced by athletes. However, there are contradictory results about the effect of the pathway of this supplement on increasing factors related to hypertrophy or reduction of atrophy. The present study investigates the effect of HMB and resistance training on response to Muscle MuRF1 and P70S6K in inactive men. To this end, 40 inactive men with the average age (25. 5 ± 5 years) and a BMI of (21. 2 ± 2 kg/m2) were divided into the following four training categories: training, training+HMB, HMB and control. The subjects did bodybuilding exercises (3set/10-12repitations/75%-80%1RM) for four days a week over a six-week time period. The control group did not do any kinds of exercise. The vastus lateralis muscle biopsy and 1RM amounts of each subject in leg press movement were conducted and measured before and after six weeks of training and consuming the supplement. The results of one-way ANOVA and repeated variance analysis test with inter-group factor showed that there is a difference (P= 0. 001) between the increase of 1RM before and after six weeks of training and the amounts of P70S6K (P= 0. 001) in all three groups in comparison with the control group. However, this difference was not significant (P= 0. 22) in MuRF1 amounts. As a result, consuming HMB supplement in the course of training can lead to the increase of P70S6K response as a marker of hypertrophy and an increase of strength in the leg press after six weeks.

The aim of this study was to evaluate the effect of six weeks of continuous and periodic aerobic exercise on total antioxidant index of hippocampus and balance in rats with Parkinson's disease. Twenty-four Wistar male rats (250-350 gr) were used in this study. Subjects were infected with reserpine to Parkinson's. Then, continuous and periodic aerobic exercises were performed for 6 weeks and 5 sessions per week with a time of 15 minutes and a speed of 10 meters per minute in the first week, the training time in the last week reached 40 minutes and the training speed reached 20 meters per minute. This exercise was performed in the periodic group in the first week in two stages, in the second to fourth week in four stages, and in the fifth and sixth weeks in six stages. They were killed by ketamine and xylazine, then the hippocampal tissue was isolated from other parts of the brain and the total antioxidant index (TAC) was measured. The results were analyzed using one-way analysis of variance and LSD post hoc test. The results of this study showed that 6 weeks of continuous and interval aerobic exercise improved the total antioxidant index (P≤ 0. 00), and the balance (P≤ 0. 00) of parkinsons rat. Also, there was no significant difference between the two training groups in the total antioxidant index (P≤ 0. 46), but in the interval exercise equilibrium index, there was a significant difference between the two exercises (P≤ 0. 00), Therefore, it can be concluded that these types of exercises can be used to Improve the hippocampal antioxidant system and balance of Parkinson's patients.

The purpose of this study was to describe change process of some characteristics of physical fitness and motor skill of male and female volunteers participating in the entrance exam of physical education and sports science between the years of 2005 and 2015. Accordingly, information on available data from tests held between 2005 and 2015 – (except for 2007 and 2009 was not available) for 58449 subjects including 37, 917 female subjects and 20, 532 male subjects in all cases of practical was examined. Then, the change process of some variables in different years and in both sexes were statistically analyzed. Accordingly, the results of this study showed that the process of changes in the physical and motor fitness characteristics was slowly and gradually taking place (chin-up, girls medicine ball throwing, soccer and basketball dribbling record had a downward trend and curl up, boys medicine ball throwing and total time of tests had a unchanged trend). Further analysis of the results indicated that the physical fitness in boys and the motor skills readiness among the girls have more changing (The boys' skill readiness scores for dribbling tests were lower than girls, and vice versa). The results of this research emphasize the more attention of experts in this field to the development of scientific and practical programs in reducing the process of changes in physical fitness and skills of the young generation of the our country.

The aim of present study was to perform a meta-analysis on the conflict results of several surveys about the effectiveness of saffron supplementation on enzymatic antioxidant defense biomarkers in exercise. This meta-analysis has collected results from four qualified studies. All researches were control case study (n=70) and had evaluated the effectiveness of saffron supplementation before aerobic exercise on Catalase and Superoxide Dismutase (SOD) enzymes amounts. Regard to non-significant P-value (P=0. 155) in I2 index, fixed effects model has been used. The statistical analyze of research was done by Comprehensive Meta-Analysis Version 2, and the effect size was measured by Standardized Mean Difference (SMD). Generally, 10 effect sizes were observed in researches which five effect sizes were positive and five effect sizes were negative. According to the results, SMD of antioxidant enzymes in saffaron group (SMD=0. 671) was significant toward control group (Confidence interval= 0. 337-1. 005, P=0. 01), and SMD of antioxidant enzymes in saffaron+exercise group (SMD=0. 77) was also significant toward control group (Confidence interval= 0. 436-1. 105, P=0. 01). In the case of estimating antioxidant defense via Catalase, SMD in saffaron group (SMD=0. 604) was significant toward control group (Confidence interval= 0. 048-1. 161, P=0. 05), whereas SMD in saffaron+exercise group (SMD=0. 243) was not significant toward control group (Confidence interval=-0. 302-0. 789). In the case of estimating antioxidant defense via SOD, the SMD in saffaron group (SMD=1. 464) was significant toward control group (Confidence interval=-0. 846-2. 082, P=0. 01), and SMD in saffaron+exercise group (SMD=1. 306) was also significant toward control group (Confidence interval= 0. 705-1. 908, p=0. 01). Based on collecting the studies results, it can be concluded that saffron supplementation may enhance enzymatic antioxidant defense and lower exercise inducedoxidative stress. However, the most effectiveness of saffron has observed on SOD enzyme amount, whereas saffron effectiveness on exercise induced-Catalase amount was not proven in this study.