نشریه مطالعات کاربردی علوم زیستی در ورزش
پیاپی 20 (زمستان 1400)

Exercise can causes neurogenesis in the brain of adult mammals. Until now few studies investigated how the effect of exercise on neurogenesis. The aim of the present study was examine the effect of the running time on cell proliferation in the hippocampus of adult male rats.

Eighteen adult male rats following one week of familiarization with treadmill were randomly divided into three groups including of control group (n=6), 30-min running group (n=6) and 60-min running group (n=6). The animals in running groups were subjected to daily 30-min and 60-min treadmill exercise sessions with velocity of 12 meter per minute for 14 consecutive days. At the last 10 days, animals received daily injections of bromodeoxyuridine (BrdU) in a specific dose to label dividing cells. After 48 hours of the last session of running, the animals were sacrificed and their brain was removed for immunohistochemichal analysis. The one-way analysis of variance followed by least significant difference (LSD) post hoc test was used to analyze the data at the significant level of p<0.05.

The number of Brdu+ cells increased significantly both after running for 30 (p=0.001) and 60 (p=0.001) minutes; so that these changes were significantly higher after the 60-min than to the 30-min running (p=0.001).

The results of this study showed that running regardless of time traveled per day increases cell proliferation in the hippocampus of adult male rats; so that the longer the time, the greater the rate of cell proliferation.

In recent years, various methods of cryotherapy have been used to reduce intensive exercise-induced injuries and inflammation for fast and complete recovery as well as exercise capacity elevation. Therefore, the purpose of this study was to investigate the effects of cold water immersion (CWI) following a Wushu specific training session on the anabolic/catabolic indices and cellular damages.

Sixteen elite Wushu athletes from Kurdistan province (mean age: 19.17±2.80 years, weight: 77.37±8.30 kg, body fat: 10.25±30%) were selected as the subjects and performed a Wushu training session. During the recovery period, the subjects of the CWI group immersed in the cold water for 20 minutes, while control group rested passively in the same position. Blood samples were collected immediately before and after training and after recovery period. To analyze the data, analysis of variance with repeated measures and Bonferroni tests were applied at the significant level of p<0.05.

There were no significant changes in the level of Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) enzymes following a training session (p>0.05). The level of growth hormone, testosterone, and the testosterone/cortisol ratio increased significantly after training in both groups (p<0.05), while following the recovery period, testosterone level decreased only in the CWI group (p<0.05). Moreover, cortisol level decreased significantly after recovery period (p<0.05), but there was no significant difference between the two groups (p>0.05).

The levels of anabolic hormones (growth hormone and testosterone) reduced by ICW following a Wushu training session; and it seems that the use of this method can attenuate exercise-induced positive responses and it may have long-term negative effects on athlete’s performance.

Micro-RNAs (miRNA) are short RNA molecules that as significant regulators of physiological processes associated with obesity play important roles in body; this is while the combination of effect of interval and continuous aerobic training along with calorie restriction can affect the gene expression of miR-146a and some inflammatory factors like tumor necrosis factor- α (TNF-α), interleukin -6 (IL-6) and C-reactive protein (CRP). Therefore, the aim of the present study was to determine the effect of two types of exercise training along with intermittent calorie restriction (ICR) on miR-146a expression and TNF-α, IL-6 and CRP levels in obese women.

Twenty-eight women were selected by targeted sampling from obese women aged 35-45 years in Tabriz city and were divided randomly into four groups including of ICR (ICR, 20 percent), high intensity interval training and ICR (10 percent calorie restriction from exercise and 10 percent ICR), a combination of continuous aerobic training and ICR (10 percent calorie restriction from exercise and 10 percent ICR) and control groups. Interval training (up to 75-95% of the maximum reserve heart rate) and continuous training (up to 60-75% of the maximum reserve heart rate) was performed for 8 weeks with repetition of 3 sessions per week. Dependent variables were measured before the intervention and 72 hours after the last training session. Results were extracted using Shapiro-Wilk, repeated measure analysis of variance and Bonferroni tests at the significance level of p<0.05.

Both training groups with calorie restriction compared to the control group showed a significant increase in maximal oxygen uptake and miR-146a expression and a significant decrease in TNF-α, IL-6 and CRP (p<0.05). While, there was no significant difference between the two groups of interval and continuous aerobic exercise with calorie restriction (p<0.05.)

Doing exercise (regardless of whether it is interval or continuous) and limiting daily calorie intake can be effective in reducing chronic inflammation in obese people and can be used as a non-pharmacological method to help solve the problems of these people.

The effect of occlusion training at different time intervals on muscle growth factors in girls is a new topic. Therefore, the present study conducted to study effects of resistance training with and without vascular occlusion on serum levels of some anabolic and catabolic hormones in active girls.

For this purpose, 36 female students of physical education with an average body mass index of 23.32±2.79 kg/m2 were divided into three groups (n=12) including resistance training without vascular occlusion, resistance training with vascular occlusion, and control groups. Exercise groups performed resistance training for 30 minutes, three sessions per week, for six weeks and vascular occlusion was applied by closing the tourniquet around the proximal arm with a pressure of 100 mmHg. Fasting blood samples were collected before the start, 24 hours after, the 6th session, and the 18th session of the exercise protocol. Serum levels of insulin-like growth factor-1, growth hormone, cortisol, testosterone, and insulin were measured by Elisa method. To extract results, the analysis of variance with repeated measures and Bonferroni post hoc tests were applied at the significant level of p<0.05.

The results showed that after six weeks of intervention, the occlusion and non-occlusion resistance training reduced significantly both cortisol (p=0.01) and insulin (p=0.01) hormones; while testosterone (p=0.95) and insulin-like growth factor-1 (p=0.82) did not change significantly.

The results showed that low-intensity occlusion resistance training can induce alterations in the insulin and cortisol hormones similar to high-intensity non-occlusion resistnace intervention.

Inflammatory factors and related disorders (including insulin resistance) increase with the onset of menopause in overweight women; thus the aim of the present study was to investigate the effect of eight weeks of aerobic exercise training on plasma levels of calprotectin and insulin resistance in overweight post-menopausal and peri-menopausal women. 

Twenty seven overweight women (BMI>25 kg/m2) participated in this study. Subjects were divided into two groups including 13 post-menopausal women (mean age 53.46‌±‌‌5.76 years), and 14 peri-menopausal women (mean age 32.50±7.85 years). The training program consisted of eight weeks of aerobic exercise training, three sessions per week, up to 40-80% of maximal reserve heart rate; each session lasted 25 minutes in the first week and reached to 45 minutes in the 8th week of training. Plasma levels of calprotectin, insulin, glucose, and insulin resistance index (HOMA-IR) were measured before and 48 hours after the end of training. Paired t-test was used to determine intragroup changes; while analysis of covariance (ANCOVA) test were applied to compare intergroup changes at the significant level of p<0.05. 

The results of paired t-test showed that plasma levels of calprotectin increased significantly in both post-menopausal (p=0.01) and peri-menopausal (p=0.04) women after exercise; but the analysis of covariance test did not show any significant differences (p=0.80) between two groups. Moreover, plasma insulin (p=0.009) concentration and insulin resistance (p=0.03) significantly reduced in post-menopausal women, while in peri-menopausal women was associated with a significant increase (p=0.01) in insulin resistance. 

The results of this study showed that aerobic exercise training increases the levels of calprotectin in overweight post-menopausal and peri-menopausal women, and this increase appears to be independent of changes in insulin and insulin resistance in these women.

Alzheimer’s disease is a progressive disorder of the nervous system. Inflammation plays an important role in neurological dysfunction and loss of neuronal cells in Alzheimer’s disease. Previous studies have shown that cAMP response element-binding protein (CREB) activity decreases with beta amyloid and inflammation. Therefore, the purpose of this study was to investigate the effect of aerobic training before and after induction of Alzheimer on interleukin-1β (IL-1β) and CREB gene expression of Wistar male rats.

The number of 115 male adult rats (eight-week old) with an average weight of 250±17.20 grams in the pre-Alzheimer’s stage were randomly divided into two equal resting (55 heads) and exercise (55 heads) groups. After four weeks and after induction of Alzheimer’s disease, the rats of each group were divided into three subgroups including Amyloid injection, injecting the placebo, and without injection groups. Before the start of the study, animals were killed (5 heads in each group) and their hippocampus removed after four weeks of training (before and after Alzheimer’s induction). IL-1β and CREB expression were measured by Real Time-PCR method and data were analyzed in two stages before and after Alzheimer’s induction with one way- analysis of variance and least significant difference (LSD) tests at the significant level of p≤0.05.

Both in the pre and post-Alzheimer’s stages, IL-1β and CREB expression decreased and increased significantly (p<0.05) in the training group compared to the resting group, respectively.

Aerobic exercise can increase of CREB expression and reduction of inflammation before and after Alzheimer’s induction, and it probably contributes to hippocampal plasticity in this way and has cognitive or functional benefits.

COVID-19 prevalence has a tremendous effect on almost all aspect of human life and wearing respiratory facemasks are recommended as a means of virus control. The aim of the current study was to examine the effect of using medical masks on cardiovascular responses and rating of perceived exertion (RPE) in healthy women during a submaximal exercise (SE) protocol.

This randomized study conducted to evaluate the effects of respiratory facemasks (N95 versus surgical), or no mask status, following a submaximal exercise (with 60 to 70% intensity of maximal heart rate) in three groups of healthy volunteers females (mean age and body mass index of 28.3±6 years and 23±3 kg/m2, respectively). Participants divided into submaximal exercise+N95 mask, submaximal exercise+surgical mask, and submaximal exercise+Nomask groups. Cardiovascular parameters including QRS duration, QT interval, ST segment, and P wave duration were assessed by an electrocardiogram system; then data were analyzed using one-way analysis of variance and Tukey tests at the significant level of p≤0.05.

Wearing face masks had no effect on SPO2% (p=0.77), heart rate (p=0.34), QT distance (p=0.64), ST segment (p=0.58), QRS wavelength (p=0.67), and P wavelength (p=0.45)) following SE on treadmill. Values of RPE in the N95 mask group increased significantly as compared to the NoMask (p=0.006) group; while it increased insignificantly when compared to the surgical mask (p=0.06) group.

Wearing a surgical facemask, specifically surgical facemask, during a submaximal exercise protocol does not have a detrimental effects on cardiovascular markers and performance of healthy women.

Update and standardized norms is necessary for continuous physical fitness evaluation of population and their health monitoring. The aim of this research was to investigate the state of physical fitness and develop a standard norm for men and women aged 18-60 years in Birjand.

In this descriptive study, the statistical population consisted of people aged 18-60 years living in Birjand. It was used the Cochran’s sampling scheme and it is applied based of cluster sampling. Four hundred Birjand’s men and women (200 persons per each sex group) in age groups of 18-29, 30-39, 40-49, and 50-60 years old selected as statistical sample. It is applied the floor push-ups, sit & reach, sit-ups, the 1-mile Rockport walk and hand grip tests for data collection. Fat percent was determined using Jackson & Pollock formula. We applied standardized scores for providing of physical fitness norm and it was used the independent-t and Mann-Whitney U tests at the siginificant level of p<0.05 for age group and sex comparisons.

After providing of physical fitness norm, it is recognized that men in the whole groups were taller in height, bigger in waist circumference, and lower in fat percent than women and differences slope of the waist and body fat indices were rising. Women had a lower VO2max   than men in whole groups despite of 50-60 years old. On the other hand, men obtained better grip strength, and shoulder and abdomen endurance than women in whole groups. Besides, measured physical fitness characteristics have shown a decline slope in long life; while fat distribution in Birjand had a rising slope along with age and it showed biggest in 50-60 years old men and women groups.

Men have better physical fitness than women and it was observed a sensible falling in physical fitness of participants parallel to their age rising. Based on comparing to the other locations, Birjand’s population were weaker in majority of the physical fitness status and it is necessary to design feasible motor paln for their improvements.