نشریه فیزیولوژی ورزش و فعالیت بدنی
سال دوازدهم شماره 2 (پاییز و زمستان 1398)

Recently, effect of ischemic preconditioning (IPC) in sports as an ergogenic aid is taken into consideration. There are evidences that IPC may have positive effects on athletic performance and lead to increase performance capacity. So, the aim of this study was to effect of IPC on anaerobic performance of female student's athletes.

For this purpose, in a randomized crossover design, sixteen females assigned into two conditions: Experiment (preconditioning included four set of five-minute occlusion-reperfusion, with five minutes reperfusion, then performing two Wingate tests) and Control (sham preconditioning included four set of five-minutes closing cuff without pressure, then performing two Wingate tests). The rest period between two Wingate tests was two minutes. Borg scale were measured immediately after the last stage of ischemia and Wingate test. Data were analyzed using repeated measures analysis of variance and LSD test.

The results showed that the peak power increased in experimental condition compared to the control, but this increase was not statistically significant (P>0.05). Also, there was no significant difference in average power, mean power and heart rate between control and experimental condition (P>0.05). IPC lead to significant decrease in the perceived exertion in experimental condition (p˂0.05).

Results showed that the IPC has no effect on power output in female student's athletes. It seems, IPC before power tasks, must be applied in more time and intensity and in greater muscular volume.

To investigate the Effect of 30 hours sleep deprivation on shooting score and corticospinal excitability of Thenar eminence muscle in soldiers. For this purpose, 11 volunteers (male) were selected from a military training center.

In two stages, using Transcranial magnetic stimulation technique by Medtronic device as well as to register the shooting score by air rifle before and after 30 hours of sleep deprivation, the subjects were studied. Obtained data, with descriptive and inferential statistics using SPSS software version 16 and by taking 5% of measurement error, were analyzed

it was shown that 30 hours of sleep deprivation caused a significant decrease in shooting score (p=0 /003); also significantly increased the range of motor evoked potential(MEP) amplitude (p= 0/009), no significant reduction of MEP latency (p=0/98) and no significant increase in facilitated MEP latency (p=0/15) measured in the thenar of subjects.

According to the results of this study it can be concluded that 30 hours of sleep deprivation, significantly decreased the score of shooting, probably because of disturbances in corticospinal excitability following sleep disorders. Which can be explore in future research

purpose :

Obesity and overweight are associated with widespread variations in levels of sex hormones. Among the most important sex hormones that changes in their levels are related to different diseases pathogenesis can mentioned to sex hormone binding globulin (SHBG) and estradiol. However, the effect of different exercise training on this changes in sex hormones levels don’t fully understood yet. Therefore, the aim of present study was to investigate the effect of eight weeks' selected resistance training on serum levels of estradiol, sex hormone-binding globulin (SHBG) and body composition in obese and overweight premenopausal women. 

Methods:

 For this purpose, 20 premenopausal women's assigned in two experiment (mean age 44.3±2.11) and control (mean age 42.3±5.37) groups. Experiment group performed resistance training for eight weeks, three sessions in week by using elastic bands (Thera band). Resistance exercise consist of 16 movements for upper body, abdomen and lower body. Each movement performed with 10 repetitions, 3 set and two-minute interval rest between sets and one minute's rest between exercises. Data analyzed by analyze covariance test. 

Results:

 Results indicate significant increase in SHBG and decrease body fat percent. Serum levels of estradiol decrease in experiment group but this decrement not significant Statistically. Discussion. According to present study results it seem that resistance training with Thera band have positive effects on modulate sex hormones levels in women with overweight.

The use of nutritional interventions such as dietary supplements is recommended to prevent early onset of fatigue, physical activity pressures, and improved performance during the race. The aim of this study was to examine The effect of four weeks HIIT training with ginseng supplementation on aerobic, anaerobic powers and body composition of Overweight and obese females.

In this quasi-experimental study, 40 overweight women with mean and standard deviation were weight 77.30 ± 9.97 kg, age 33.1 ± 3.15 years old, and 39/36 ±3.4, which are purposefully grouped in four supplement, supplement & practicing, practicing and controlling groups. The HIIT practice protocol lasted for four weeks and three sessions a week, and each session was 4-6 and each set was 30 seconds, fast paced with 80% HRm and 270 seconds fast walking for the two groups. Each participant in supplement and supplement & practicing groups has taken one 500 mg capsule ginseng supplement for four weeks each day. The fat percentage was measured by the Jackson-Pollack three-point method and peak power output (PPO), maximum power point (MPP), and fatigue index (FI) measured by the 30-Seconds Wingate test and Quin's test method. The data were analyzed covariance analysis with using SPSS software.

As the results of covariance analysis showed that supplementing Ginsing with HIIT exercises on maximum aerobic power ; Peak anaerobic power ; average anaerobic power ; Minimum anaerobic power; weight ; fat percentage ; WHR; BMI There is significant difference between the four groups but There is not significant difference between four groups in LBM

Intense interval training with ginseng supplementation improves aerobic and anaerobic capacity and body composition (body fat percentage, weight, WHR ratio and BMI) of women with overweight and obesity. Keywords: Intense Interval Training, body composition, ginseng supplementation, women with overweight and obesity

have shown that exercise in many species leads to increase and improvement in cardiac function. It seems that variety of exercise increases the myocardial regeneration capacity by increasing the formation of new cardiomyocytes. The present study examines the effect of high intensity interval and continues training on cardiac stem cells function and myocardial regeneration capacity in male rats.

Twenty four Vistars male rats were divided into three groups HIIT,continuous and control. The protocol training were performed 5 sessions per week for 6 weeks.The heart rats were extracted and c-Kit and Ki67 values were analyzed by Immunohistochemistry and Nkx2.5 gene expression for cardiac stem cells was measured by Real Time-PCR. The data were analyzed by one way ANOVA (P≤0.05).

According to the results of this study, there was a significant increase in c-Kit cells in the HIIT (P≤0.00) and in the continuous group (P≤0.018) and Significant increase in positive Ki67 cells in the HIIT group (P≤0.00) and continuous group (P≤0.05. this increase was greater in the HIIT group. As well as a significant increase was observed in the expression of Nkx2.5 gene expression in the HIIT training group (P≤0.015) and in the continuing group (P≤0.03) which increased in the continuous group was grater.Conclusion It seems exercises training induce heart regeneration through increased stem cell proliferation, c-Kit differentiation and increases gene expression of Nkx2.5, which are the two primary causes of the early regeneration of the heart, that lead to production of new cells in heart tissue.

Multiple sclerosis or MS is an autoimmune disease of the central Nervous system and the most common cause of disability among young adults. TH17 cells play an important role in the development of autoimmune diseases, including MS, and the effects of IL-17 in the process of demyelization of nerve cells in MS patients. The aim of this study was to investigate the effect of eight-week yoga training on serum levels of IL-17 in women with multiple sclerosis.

For this purpose, 16 females with MS (with a mean age of 37.8± 7.7 years, height 161.7± 7.4cm weighs 70.7±18.2 kg) and EDSS <4 were selected. Subjects were randomly assigned to yoga (n=8) and control (n=8) groups. Yoga Group participated in yoga classes for eight weeks (three times a week), while the control group continued their routine activities. Blood samples were collected 48 hours before and 48 hours after exercise and serum levels of IL-17 assessed by ELISA kits. Data analysis was performed with SPSS22 software and using independent t-test at a significance level of P≤0/05.

The results of statistical analysis showed that the level of IL-17 in the experimental group significantly decreased compared to the control group (p = 0.001).

Based on the results of this study, eight weeks of yoga training, by reducing serum levels of IL-17, play an important role in helping to improve the condition of MS patients.

The aim of study examines the effect of 8 weeks resistance- interval training on telomere length and telomerase activity in sedentary young men.

Twenty sedentary male students from Islamic Azad University of Eslamshahr were selected and randomly assigned to two groups of training (N=10) and control group (N=10). The training protocol consisted of interval resistance and endurance training, each session consisting of two steps. The first step was an interval training consisting followed by 30 minutes. In the second stage, resistance training was performed for 30 minutes. Blood samples were taken a half hour before the first training session and 24 hours after last training session, 10 ml of blood was taken from the brachial vein of the subjects. Independent and dependent t-test was used for data analysis and significance level in all tests was considered P≤0.05.

The findings of present study revealed that eight weeks of interval resistance training prevented the telomere length shortening and increased telomerase activity. In addition, TRF2 levels were significantly increased compared to pre-training.

Finally, eight weeks of interval resistance training significantly increased the quality of life of the subjects. Therefore, it seems that eight weeks of interval resistance training can have a beneficial effect on telomere biology and quality of life. Hence, it is suggested that young people consider a regular interval resistance training in their everyday lives in order to have a better quality of life and lower stress, and that they safe from relate to many diseases and risk factors associated with inactive lifestyle.

Blood pressure is affected by various factors including activity. The aim of this study was to investigate the effect of eight weeks of aerobic training on blood pressure, nitric oxide and apelin in women with pre-hypertension.

Twenty-four women aged 30-45 years with pre-hypertension were randomly divided in two groups: aerobic and control. Aerobic exercise was performed three times a week for eight weeks, This means that subjects the first week for 30 minutes at 50% heart rate reserve, the second and third weeks respectively were 35 and 40 minutes with a 50% intensity, Fourth week 40 minutes and intensity 55%, and 5th, 6th, 7th and 8th weeks run For a period 45 minutes with 55% heart rate reserve. Blood pressure measurement and blood sampling were performed one day before the first and 48 hours after the last exercise. Apelin and nitric oxide levels were measured using commercial kits by ELISA method. Statistical analysis of data was performed using independent and dependent t-test at a significant level (p <0.05).

After 8 weeks of aerobic activity, the levels of apelin and nitric oxide increased significantly in the training group (p <0.05). If the blood pressure level decreased significantly (p <0.05).

8 weeks of aerobic training can be beneficial for people with pre- hypertension by increasing nitric oxide and apelin levels and lowering blood pressure.

Aging is associated with systemic dysfunctions in lipid metabolis and chronic inflammatory state which contribute to atherosclerotic. The purpose of this study was to investigate the effect of moderate and high intensity resistance training on micro-RNAs Associated with reverse cholesterol transport in Wistar elderly rats.

30 male Wistar rats (23 months old) were randomly divided into two experiment and one control group including moderate intensity resistance training (n = 10), high intensity resistance training (n = 10) and the control group (n = 10). Resistance training included 8 weeks of climbing a ladder with high intensity (80% MVCC) and moderate intensity (60% of MVCC) and 5 days a week. After completing training, expression of mir-33 and miR-144 and ABCA1 were measured RT-PCR . The statistical analysis was performed using Anova test with significance level of (P <0.05).

There was significance decrease in expression Of miR-33a and miR-144 and increase in expression Of ABCA1 in both high and moderate resistance groups (P <0.05). Also, there was significant difference between the mRNA expression Of ABCA1 levels in high and moderate resistance training. However, there was no significant difference expression Of miR-33a and miR-144 level between groups.

It seems that moderate and high intensity resistance training can cause decrease the expression Of miR-33a and miR-144 result to increase in mRNA expression Of ABCA1 .