فصلنامه علوم زیستی ورزشی
پیاپی 41 (تابستان 1398)

Increasing oxidative stress is a major factor in metabolic syndrome associated with obesity and may play a major role in the pathophysiology of various diseases such as cardiovascular diseases. The aim of this study was to investigate the effect of 8 weeks of rope training with portulaca supplementation on antioxidant biological indices (SOD, TAC, GPX) and lipid peroxidation index (MDA) in non-active girls. In this quasi-experimental study, 40 overweight and obese girls (mean BMI=27.05 ± 0.72, age range=20-25 yr) were selected from qualified subjects and randomly assigned to four groups: placebo (n=10), supplement (n=10), training (n=10) and training+supplement (n=10). The training program included 8 weeks of rope training (four sessions per week and 45 minutes each session), and daily supplementation of 1200 mg portulaca for 8 weeks. The variables were measured by ELISA method. The data were analyzed by ANOVA test at a significance level (P<0.05). The results showed that the amounts of MAD in training+supplement and training groups decreased significantly (P=0.01, P=0.001) and SOD, GPX and TAC increased significantly in training, supplement and training+supplement groups [SOD (P=0.001, P=0.03, P=0.001), GPX (P=0.02, P=0.007, P=0.004), TAC (P=0.02, P=0.01, P=0.001) respectively]. It seems that incremental interval endurance training as rope training along with portulaca supplementation can improve the status of antioxidant system and reduce oxidative damage and may influence preventing cardiovascular diseases.

The aim of the present study was to determine the effect of creatine supplementation along with two types of recovery (in-and-out of water) on C-reactive protein (CRP) and malondialdehyde (MDA) as systemic inflammatory indices and lipid peroxidation and also swimming record in trained female swimmers. In this semi-experimental study, 16 trained female swimmers were divided randomly into two groups: in-water active recovery and out of water active recovery. They performed 6 bouts of 50m sprint swimming with 120s rest intervals actively in-out of water, in-and-out of water before and after 6 days of creatine supplementation. The three-way analysis of variance showed that 6 bouts of sprint swimming significantly increased MDA and CRP (P=0.001). Although the recovery type (in-and-out of water) had no significant effects on MDA, CRP and sprint swimming performance, creatine supplementation significantly reduced MDA (P=0.018) and improved swimming performance (P=0.006) in both recovery groups. It seems that specialized and non-specialized recovery strategies do not affect inflammation and stress inhibition resulted from HIIT, but creatine supplementation can reduce the systemic stress resulted from HIIT and maintain sprint swimming performance.

Training along with vascular occlusion is useful for increasing power and hypertrophy. The aim of this study was to investigate the effect of conditioning training based on small-sided games with and without vascular occlusion on some physical fitness factors in female basketball players. 30 female basketball players participated in this study voluntarily and randomly divided into three groups: small-sided games with vascular occlusion (n=10), small-sided games without vascular occlusion (n=10) and control (n=10). Training program included 6 weeks, 3 sessions a week and involved 15-28 minutes of training on a court with 15 × 14 dimensions and 20 minutes of training on the basketball court. The proximal portion of both legs of the vascular occlusion group was occluded with elastic band before the beginning of the main training. Data were analyzed using ANCOVA test at significance level of 0.05. The results indicated a significant increase in the power of lower body muscles in small-sided games with vascular occlusion group compared with the small-sided games and control groups (P=0.001) while there was no significant difference among the three groups in 10m and 20m speeds and maximum power. Also, aerobic power index significantly improved in small-sided games with vascular occlusion group compared with the control group (P=0.026). There was no difference between small-sided games and small-sided games with vascular occlusion (P=0.25). According to the results of this study, it is suggested that the small-sided games with vascular occlusion should be employed to improve the power of lower body muscles and both training methods should be used to improve aerobic power in female basketball players.

Omentin-1 (adipokine derived from visceral adipose tissue) is associated with the development of diabetic disorders (such as insulin resistance and dyslipidemia). While aerobic exercises are employed due to their positive effects, new research has shown that medicinal plants are effective in improving the health and preventing and treating diabetes. One of these plants is the Stevia plant. The aim of this study was to investigate the effect of aerobic exercise and stevia extract consumption on serum omentin-1 and lipid profile in diabetic rats. 35 male rats (180-220 g weight range) were randomly divided into non-diabetic control, diabetic control, diabetic exercise, diabetic extract, and diabetic exercise along with stevia groups. Aerobic exercises included running on the treadmill, 5 days a week for 6 weeks and the extract was received in the same period. At the end of the intervention, blood samples were collected to measure the omentin-1 levels and lipid profile. Data were analyzed by one-way ANOVA and Tukey test.Results showed that omentin-1 levels in diabetic control group were lower than non-diabetic control group (P=0.001). The aerobic exercise program and stevia consumption significantly increased omentin-1 and HDL and significantly decreased TG, TC, LDL and VLDL in the experimental groups compared with the diabetic control group (P<0.05). These results indicated an increase in omentin-1 and improvement of lipid profile after aerobic exercise and stevia extract consumption. These effects were higher when exercise and stevia were used simultaneously.

One of the consequences of aging is reduced testosterone and IGF-1, which can lead to muscular atrophy and motor weakness in the elderly. The aim of this study was to investigate the effect of 8 weeks of resistance training with tribulus supplementation on plasma levels of testosterone and IGF-1 in elderly men. 44 elderly men (mean age: 64±2.80 yrs) were selected and randomly divided into 4 groups (each group 11 subjects): resistance training + supplementation (ES), resistance training + placebo (EP), resistance training and control. The training groups performed resistance training protocol for 8 weeks, 3 sessions per week. ES group used 1250 mg of tribulus supplementation per day. ELIZA method was used to measure biochemical parameters and ANCOVA was used for data analysis.The results showed a significant difference between the ES group and the other groups in the testosterone and glucose variables (P<0.001). In other groups, there was no significant difference in these variables. There was no significant difference in IGF-1 and BMI among the groups. Finally, the findings of this study showed that tribulus supplementation along with resistance training could increase the testosterone level in the elderly men and reduce blood glucose level.

Most studies have commonly utilized traditional resistance training in training periodization and the effect of resistance training with blood flow restriction is not perfectly clear in this periodization. Therefore, the aim of this study was to compare the combination of eight weeks of resistance training with blood flow restriction and traditional resistance training based on linear and undulating periodization on hypertrophy, strength, muscular endurance and power in active girls. 26 active girls were randomly assigned to three groups: resistance training with no periodization, linear periodization and undulating periodization. Traditional strength training (TST) was performed with the intensity of 75% 1RM and blood flow restriction training (BFRT) was performed with the intensity of 30% 1RM. In linear periodization group, subjects performed BFRT during the first 4 weeks and TST during the second 4 weeks. In undulating periodization group, participants switched from BFRT to TST every session. The non-periodization group performed TST with constant intensity. For analyzing the data, one-way ANOVA was used. The results showed a significant increase in all groups from pretest to posttest for rectus femoris and vastus medialis cross sections, strength and endurance of quadriceps and hamstring and explosive power of legs. There was no significant difference among the groups in no variables except for vastus intermedius cross section. Combination of BFRT and TST in the form of linear or undulating periodization and non-periodization resistance training have both similar effects on hypertrophy, strength, endurance and explosive power of legs in active girls.

One of the mechanisms involved in muscle atrophy is TRAF6/MuRF1 path, which may increase muscle breakdown. The aim of the present study was to investigate the effect of high intensity interval training (HIIT) on gene expression of MuRF1 andTRAF6in EDL muscle of aged C57bl/6 mice.  For this purpose, 28 C57bl/6 aged (n=14) and adult (n=14) mice of each group were assigned to two groups: training (n=7) and control (n=7). After one week of familiarization, training groups participated in 4 weeks of HIIT program. The mice were sacrificed 48 hours after the last training session and their EDL muscle were extracted and the gene expressions were measured with Real-time PCR technique. The comparison of aged and adult groups showed that aging had a significant effect on MuRF1 and TRAF6 mRNA gene expression (P=0.005 and P=0.004 respectively). Also, training drastically influenced MuRF1 and TRAF6 expression (P=0.0001). The findings also showed that aging had a significant effect on EDL muscle weight as a significant difference was observed between aging and adult control groups (P=0.032). But this amount was not statistically significant in both adult (P=0.117) and aged (P=0.321) groups. Thus, aging is associated with an increase in MuRF1 andTRAF6gene expression, which could possibly be involved in muscle mass changes associated with aging. Since high intensity interval training decrease the expression of these genes, it can be utilized to maintain muscle mass during aging.