نشریه ورزش و علوم زیست حرکتی
سال پنجم شماره 1 (پیاپی 9، بهار و تابستان 1392)

Introduction and Purpose:

microRNAs (miRs) are involved in cellular different processes and inhibit gene expression. One of these miRs is microRNA-1 (miR-1) which is special in muscles-tissue and the rate of it decreases with muscular hypertrophy. Regarded to difference of slow and fast muscles to resistance exercise، the purpose of this study was to evaluate the effect resistance exercise (RE) on miR-1 expression in fast and slow skeletal muscles of Wistar male rats.

The subjects of this Fundamental study were15 rats that were randomly assigned to RE (n=10) or control groups (n=5); the RE group performed one session RE (climbing a 1-meter–long ladder with 4 set، 5rep)، then 3 and 6 hours after RE with control group were anaesthetized and sacrificed، the soleus and Extensor digitorum longus (EDL) muscles -slow and fast twitch skeletal muscle respectively- were removed. The miR-1 expression rate was determined by Real time RT-PCR method. To analysis of dates the one sample t test and independent t test were used.

The results showed that in response to RE، the expression of EDL miR-1 was significantly decreased 99 and 73 percent at 3 (P<. 0001) and 6 hours (P<. 0001) after exercise respectively. While the expression of soleus muscle miR-1 decreased by 40 percent (P<. 323) and then increased 224 percent (P<. 196) at 3 and 6 hours after RE respectively but these changes were not significant. Discussion and

one session RE induce decrease in miR-1 in EDL muscle، it is probably a sign of proliferation in EDL muscle.

unlike regular exercise، acute exhaustive exercise may be elicits damage to the heart. The aim of this study was to comparing the effects of acute exhaustive exercise on cardiac troponin T serum and malondialdehyde of heart tissue response levels of endurance trained young rats

48 Wistar male rats were assigned into following three groups (N=16): 1. control (without exercise); 2. experimental (8 weeks exercise + an acute bout of exhaustive exercise); 3. experimental (8 weeks exercise + three acute bout of exhaustive exercise). The end of experimental، half of rats were killed immediately before exhaustive، but the remaining rats were killed immediately after performed an acute bout of exhaustive exercise on the treadmill. malondialdehyde of heart tissue and Cardiac troponin T serum levels were measured by ELISA and TBARS methods، respectively. Data were analyzed by one – way ANOVA

The results show that malondialdehyde of heart tissue group1 (34. 63%)، group2 (31. 09%)، group3 (18. 13%) and Cardiac troponin T serum، group1 (288%)، group2 (162. 5%)، group3 (82. 3%)، were significantly increased following an acute bout of exhaustive exercise compared to before exhaustive. Nevertheless، the increased in group3 was significantly less than other groups (P<0. 05).

Based on the results، it can be concluded that 3 consecutive bout of exhaustive exercise after the 8 weeks exercise compare to singly 8 weeks exercise effectiveness provided protection from myocardial damage induce an acute bout of exhaustive exercise.

The purpose of this study was to determine the impact of swimming on appetite، energy intake (EI) and composition of foods in young females.

The aim of the present study was to investigate the responses of plasma visfatin to resistance exercise volume and its relationship with insulin resistance index، IL-6 and growth hormone. Fifteen healthy young subjects (age: 23. 9±1، weight: 74. 4±7. 2، BMI: 26. 1±3. 6) were volunteered to participate in the study. After familiarization and determining the maximum strength (1-RM)، subjects performed two resistance exercise protocols of 3-sets and 5 sets randomly at two separate occasions with one week intervening. Three blood samples were taken before exercise، immediately after exercise and after 30 min recovery، and were analyzed for growth hormone، interlukin-6 (IL-6) and visfatin. Insulin resistance index was calculated using glucose and insulin concentrations. To compare the responses of parameters to exercise and recovery، the differences between pre and post exercise as well as pre and post recovery data were calculated and compared by using paired t-test. Results showed that there were no significant differences between the responses of these parameters to two resistance exercise volumes (P>0. 05). Irrespective of resistance exercise volume، single session of resistance exercise resulted in significant (P<0. 001) changes in all variables except for visfatin. Investigating the statistical correlations of data in response to exercise showed no significant relationship among all variables with visfatin. The results of this study show that resistance exercise volume is not an affective factor on plasma concentration of visfatin and that visfatin cannot be considered as one of the affective factors in insulin resistance process.

Introduction and

Brain natriuretic peptide (BNP) is principally synthesized and released by ventricular myocytes in response to myocardial wall stress. Acute and chronic effects of resistance and endurance exercise on N- terminal pro brain natriuretic peptide (NT pro BNP) are still unclear.

The aim of this study was to investigate the acute and chronic effects of resistance versus endurance training on NT pro BNP level in middle-aged men.

Twelve middle-aged men were randomly assigned to resistance or endurance group. Resistance training consisted of 8 weeks weight training، 3 days a week، at an intensity corresponding to 50% of one-repetition maximum. The endurance training programme included continuous running at an intensity corresponding to 70% of maximal heart rate، 3 days a week for 8 weeks.

The results demonstrated that NT pro BNP increased (P<0. 05) after a session of endurance training، however it decreased (P<0. 05) after 8 weeks endurance training. Besides، NT pro BNP has not significant change after a session of resistance training، while it increased (P<0. 05) after 8 weeks resistance training.

In summary it seems that the acute and chronic effects of resistance exercise differ with the effects of endurance exercise. Endurance training improved myocardial function compare to the resistance training; however further studies are needed. Key words: NT pro BNP، Myocardial damage، Endurance exercise، Resistance exercise، middle-aged men.

Introduction and Chemerin is a chemokine that is involved in inflammation and resistance insulin development. Thus، recent study evaluated The ffect of 8 weeks intense resistance training on plasma levels of chemerin and insulin in male rats. 24 male Wister rats (mean weight، 161 ± 23 g and age 5 weeks) were randomly divided into three groups: healthy control، insulin resistance control and insulin resistance training. The rats in insulin resistance training group were subjected to a resistance training program (3 days/wk، for 8 wk) consisted of climbing a ladder carrying a load suspended from the tail. Following eight weeks resistance training plasma chemerin، insulin، glucose and lipid profile concentrations were measured. The findings showed that resistance training was lead to a significant reduction in plasma chemerin (p= 0. 01)، glucose (p= 0. 001)، insulin (p= 0. 001) and plasma LDL (0. 007) and significant increase in plasma HDL cholesterol (p= 0. 03) in insulin resistance training group. It seems that resistance training with high-intensity can be focused as a prevention approach in insulin resistance.

Introduction and The aim of the study was to examine the effect of short-term consumption of HMB supplementation on CK and LDH after eccentric resistance exercise in young male athletes. Twenty-four young male futsalplayer were selected and randomly divided into two groups of 12 of supplementation and placebo. Subjects consumed HMB or placebo for 6 days before a session of eccentric resistance exercise. Blood samples were taken to measuring CK and LDH in 4 times. The results showed that the effect of HMB supplementation on two markers of muscle damage (CK and LDH) is not significant but HMB supplementationcaused a significant reduction in both markers of muscle damage (CK and LDH) after eccentric resistance training on supplementation groupDiscussion and HMB supplementation can decrease markers of muscle damage، but the results cannot be used as functional supplements to reduce muscle damage markers caused by intense physical activity

The aim of this study was the comparison of two different interval and continuous exercise regimen on GH/IGF-1 axis function. Methods and Materials: 36 inactive and overweight women were divided randomly in three 12 person groups as below: interval exercise training program (average age: 23. 58±2. 27 years old، BMI 30. 60±0. 33 kg/m2، fat percentage 35. 59±0. 33 percent)، continuous exercise training program (average age: 25. 41±2. 84 years old، BMI 30. 51±0. 55 kg/m2، fat percentage 35. 54±0. 47 percent) and control group (average age: 22±2. 4 years old، BMI 30. 54±0. 51 kg/m2، fat percentage 35. 54±0. 64 percent). Both exercise regimens consisted of running in 60-75 % MHR 3 sessions per week for 8 weeks. Data were analyzed by using of paired t-test and one-way ANOVA test at P<0/05 This study showed that in the interval and continuous groups، the levels of GH and IGF-1 serum increased significantly. The amount of body fat percent in both groups decreased significantly (p<0. 05). The changes of GH and BMI levels، and the percentage of body fat were significant in the post-test values of interval، continuous and control groups (p<0. 05)، but it was not significant for IGF-1 levels. The results of the research showed that continuous exercise increases the GH levels and leads to the adjustment of weight balance.