فصلنامه علوم زیستی ورزشی
پیاپی 28 (بهار 1395)

Vaspin as a new adipocytokine improves insulin sensitivity. Despite the effects of exercise training on energy homeostasis and changes in fat tissue, few studies have investigated the effect of exercise training on vaspin. This study investigated the effect of resistance training on serum levels of vaspin and CRP. 20 sedentary obese men (mean SD age: 50.1 2.1 years, weight: 92.6 5.8 kg, BMI: 30.3 1.4 kg/m2) were selected and randomly divided into two groups: exercise (n=10) and control (n=10). Training program of the experimental group consisted of 3 sessions a week for 12 weeks. Blood samples were gathered after 12 hours of fasting and then 48 hours after the last training session in the experimental condition. Serum levels of vaspin and CRP decreased (8.8%, 2.5% respectively) in the experimental group after 12 weeks (P˂0.05). Weight, BMI, BF% and waist circumference significantly decreased (-0.7%, -0.8%, -2.08% and -1.01% respectively). Blood glucose and insulin resistance significantly decreased (respectively 4.4%, 5.01%) (P˂0.05). There was no significant relationship between changes of vaspin and anthropometric indexes, insulin resistance and CRP.

The aim of this study was to investigate the effect of 8 months of resistance training on GH, IGF1 and plasma insulin levels of patients with severe burns. The research method used was the case study with multiple base-lines for participants. The participants included two women with severe burns (age range of 20-30 years) in the “Accidents and Burns Hospital”. After determining the baseline, participants performed resistance training during 8 months of individual intervention and one month after this period, they were put under follow-up examinations for 2 consecutive months. The blood samples were collected under the fasting condition 24 hours after training at the end of each month. Based on the visual analysis, the resistance training in both participants caused changes (PND = 75% for the first participant in GH and 87.5% for the second participant, PND = 100% for both participants in IGF1 and PND = 62.5% for the first participant in insulin and 50% for the second participant). It seems that long-term resistance training can improve hormones and growth factor in patients with severe burns and consequently can expedite the treatment of the burns.

This study aimed at comparing the acute effects of voluntary contractions (PAP) at different intensities and times on explosive power, sprint ​​and agility in football players. 13 subjects (mean age 17.7±0.63 years, weight 57.9±6.9 kg and height 167.9±5.4 cm) were selected as available sample. During 7 sessions, the protocols of warm-up without load, half-squat %45, %65, %85 1RM after 4 minutes and half-squat %45, %65, %85 1RM after 15 minutes were randomly administered for the variables of explosive power, sprint and agility, and 35-m sprint running, Sargent vertical jump and Illinois agility tests were performed. Data were analyzed using analysis of variance with repeated measures (ANOVA). The results showed no significant differences in explosive power with different intensities after 4 minutes in the PAP acute effect with P≤0.05 but there was a significant difference in explosive power with 65% and 85% intensities after 15 minutes compared with warm-up protocol. There was a significant difference in the sprint in PAP after 4 minutes of 65% and after 15 minutes of 65% and 85% intensities compared with warm-up protocol. There was a significant difference in the agility in PAP after 4 minutes of 65% and 85% and after 15 minutes of 65% intensity among the intensities. Generally, time has a more effective role in improving power and sprint activities of athletes at moderate and peak intensity and agility with moderate intensity in post-activation potentiation (voluntary contractions) acute effect especially after 15 minutes.

The aim of this study was to investigate the effect of maturity level and body composition on the validity of allometric equations of VO2peak in obese and non-obese girls. 80 girls aged between 12 and 17 were randomly selected from schools in Hamedan city and divided into two groups: overweight-obese (BMI>85%) and normal (BMI0.05(. Validity of practical capacity in the obese adolescent girls with normal puberty was considerable (r =0.92, P

miR-1 is involved in many cellular processes including muscle hypertrophy (skeletal and cardiac). Endurance activities also cause cardiac hypertrophy. Therefore, the aim of this study was to investigate the effect of endurance activity on cardiac expression of miR-1. For this purpose, 14 rats were maintained under controlled conditions (temperature, light/dark (12:12) cycle, with ad libitum access to food and water) and randomly assigned to control and experimental groups after they were familiarized with the training protocol. The experimental group performed an (14 weeks) endurance training program on a treadmill; then, 48 hours after the end of the last session, they were anesthetized and sacrificed and their heart and left ventricle were removed. To determine the cardiac miR-1 expression, Real time-PCR method was used. The obtained data were evaluated using t test. Results showed no significant differences in the mean of cardiac miR-1 expression between the two groups (P =0.191). The endurance activity had no significant effects on cardiac miR-1 expression. It is likely that changes in miR-1, although low, appear in proteins level of target genes.

The purpose of this study was to determine the effects of caffeine on recovery in 2000-m rowing ergometer performance. Nine elite male rowers (age18.3 ± 1.1 year, height 185.7 ± 7.1 cm, weight 77.9 ± 8.6 kg, and body fat 8.4 ± 1.5 %) in three different trials consumed 3mg.kg-1, 6mg.kg-1of caffeine and placebo, in random order after performing 2000m ergo rowing and repeated the same trial 24hours later. There were no significant differences among the two caffeine doses and placebo in stroke rate, power, and time. Also the Values of ∆ blood lactate concentration in three treatments did not show significant differences. Creatine Kinase levels did not show significant difference in three treatments (placebo: 873.3±210.7 U.l-1, 3mg: 905.9±191.2 U.l-1, and 6mg: 933.6±228.5 U.l-1). Individual evaluation showed worse time in 5 athletes and better time in 4 athletes for 6mg.kg-1 ingestion compared to Placebo. Also 2 athletes were better and 7 of them were worse after ingesting 3mg.kg-1. It was concluded that caffeine ingestion had no effect on recovery (according to observeing no differences between CK and LT levels and performance in different ingestions) between training or trials for 2000m ergo rowing under the conditions of this study

The aim of this study was to investigate the effect of 10 weeks of endurance training on nesfatin-1 levels and insulin resistance in women with type-2 diabetes. 16 women with type-2 diabetes were selected by purposive sampling method and randomly divided into experimental (n = 8) and control (n = 8) groups. The experimental group performed endurance training for 10 weeks, 3 sessions a week (with an intensity of 40-50% maximum heart rate for 20-25 minutes at the beginning of the training session, and with a gradual increase to 70-80% of maximum heart rate and 40-45 minutes in last sessions). The control group did not participate in training during the study. Blood samples were collected after 12 hours of fasting in pretest and posttest to evaluate the nesfatin-1, insulin and glucose levels. The obtained data were analyzed in SPSS 21 using Kolmogorov-Smirnov test and independent and dependent t tests with αP0.05). Pretest and posttest changes only in glucose levels were significant in the experimental group compared with the control group (P

The aim of this study was to investigate the interactive effect of endurance training and vitamin E intake on adiponectin concentration and insulin resistance index. 30 healthy inactive women (age, 24.8±3.7 years, weight, 60.3±1.3 kg, height, 161.9±1.3 cm) were divided into three groups including vitamin E and exercise (VE), vitamin E (V) and control (C). Subjects in VE group performed a training protocol 3 times per week at the intensity of 65 to 80% of maximal heart rate and daily consumed 400 IU vitamin E at lunch for 4 weeks. Subjects in V group did not perform any exercise training. Data analysis revealed that adiponectin concentration significantly reduced similarly in all three groups (P0.05). Intra-group and intergroup comparisons for insulin concentration and insulin resistance index showed no significant differences in all groups (P>0.05). Although glucose concentration reduced significantly in all three groups, no significant differences were found among them.Therefore, it could be concluded that short-term combination of endurance training and vitamin E consumption does not influence adiponectin concentration and insulin resistance index in healthy women.

The aim of this study was to compare the effects of three types of combined training on testosterone and cortisol concentration, testosterone/cortisol ratio and muscular strength in elderly women. 40 elderly women (age range: 60.34±0.82 years) were randomly divided into four groups: endurance strength (E) (n=9), strength endurance training (S) (n=10), alternative concurrent training (ACT) (n=12) and control (n=9). The training program was performed for 8 weeks, 3 days per week. Endurance training protocol included performance on a cycle ergometer and strength training protocol involved several selected upper and lower body workouts. Paired samples t test and one-way ANOVA were used to analyze data. The results showed that 8 weeks of training did not change testosterone in S and ACT groups but a significant decrease was observed in testosterone in E group (P=0.007). In addition, results showed a significant difference in testosterone between E and ACT groups (P=0.01). In addition, no significant changes were observed in cortisol and testosterone/cortisol ratio after the training. Also, there was a significant increase in upper body strength only in E and ACT groups and in lower body strength in all groups. As there were no significant changes to basal hormones in 3 combined training groups, these subjects experienced no chronic catabolic state. Since strength increased in all groups, it seems that there was no relationship between hormonal status and the strength gains in the present study.

Optimization of training results and improvement of response requires selecting appropriate stimulus and are goals of any training program. It seems that ischemic-reperfusion preconditioning (IRPC) can be a suitable stimulus to increase submaximal contractile responses. Therefore, this study aimed at investigating the effect of ischemic-reperfusion preconditioning and remote preconditioning (IRRPC) on submaximal static and dynamic forces of young men. To this end, 20 young male students at Shahid Rajai University of Tehran were randomly selected and divided into two groups: control group (mean age of 20±1.42 years, height of 174.34±5.66 cm, weight of 71.1±6.12 kg) and experimental group (mean age of 20.5±1.33 years, height of 176.2±4.88 cm, weight of 74.45±7.09 kg). Participants performed single arm dumbbell preacher curl (weight of 8 kg) with most repetitions for dynamic movement and longest holding time of contraction at 90̊ for static movement. Pretest and posttest records were collected for both hands. In the experimental group, before the posttest, the dominant hand was under partial blood flow restriction (BFR) for 3 minutes and then the motion was carried out after one minute of reperfusion. To examine the differences between the two groups, one-way ANOVA was used. Normal data distribution was specified by Kolmogorov–Smirnov test and the level of statistical significance was P≤0.05. The results indicated that IRPC significantly increased static record (P=0.001, F=14.071) but IRRPC had no significant effects. This increase can be due to partial precompensation of temporary ischemia induced by static contractions. However, IRPC and IRRPC made no significant differences in dynamic contractile responses. Therefore, it is suggested that IRPC should be used to increase force and delay fatigue in submaximal static contractions.