پژوهشنامه فیزیولوژی ورزشی کاربردی
پیاپی 35 (بهار و تابستان 1401)

Menopause is associated with a redistribution of adipose tissue towards central adiposity, known to cause insulin resistance. Exercise training and crocin improve blood glucose and insulin resistance, and prevent obesity and type 2 diabetes.  The purpose of this study was to investigate the effect of aerobic training and crocin consumption on visceral fat cell size and insulin resistance in ovariectomized rats fed with high-fat diet. 72 female rats were divided into two groups: ovariectomized (56) and non-ovariectomized (16). Then the rats of these two groups were divided into groups fed with high-fat diet (40% fat) and normal diet. The ovariectomized rats + high-fat diet were divided into 6 groups as follows: 1- control 2- moderate intensity aerobic training 3-  high intensity aerobic training 4- crocin 5- moderate intensity aerobic training + crocin and 6- high intensity aerobic training + crocin. The target groups performed high-intensity aerobic exercise (80-85% VO2max) and moderate aerobic exercise (60-70% VO2max) and received crocin at the rate of 60 mg/kg for 8 weeks. Relative weight of perirenal visceral fat, size of cells and serum levels of glucose, insulin and insulin resistance index (HOMA) were measured. The findings were analyzed by two-way analysis of variance. Moderate intensity training with crocin consumption caused a significant decrease in the relative weight of perirenal fat (p=0.0001). Also, the relative weight of perirenal fat was significantly lower in the high intensity training + crocin group than in the high-fat diet+ ovariectomized group (p≤0.001). The fat cell size in the two training groups (moderate and intense) was significantly lower than the high-fat diet + ovariectomized group (p=0.001), and the difference between the crocin group and the high-fat diet + ovariectomized group was also significant (p=0.03). Fat cell size in exercise groups (moderate and intense) + crocin was also significantly lower than the high-fat diet + ovariectomized group (p≤0.05). High intensity training caused a significant decrease in insulin resistance (p=0.028) and glucose concentration (p=0.041) compared to the ovariectomized + high-fat diet group. Consumption of crocin decreased insulin resistance (p=0.013) and decreased insulin concentration (p=0.008). Also, moderate intensity exercise + crocin caused a significant decrease in glucose (p=0.022), insulin (p=0.011) and insulin resistance (p=0.005) compared to the ovariectomized group + high-fat diet. Consumption of crocin and aerobic training separately and in combination with can reduce visceral fat tissue weight and fat cell size and improve insulin resistance in ovariectomized rats fed with high-fat diet. High-intensity aerobic training seems to be more effective in improving insulin resistance and reducing fat cell size than moderate-intensity training. No additive effects in combination of crocin with exercise training were observed in improvement of insulin resistance or fat cell size.

The aim of this study was to investigate the effect of eight weeks of Pilates training at home and outdoor on vitamin D levels and physical fitness of women with multiple sclerosis (MS) during the coronavirus outbreak forty-four women with MS (with 2-5 EDSS) were voluntarily selected and randomly divided into three groups of training at home (n=15), outdoor training (n=15) and the control group (n=14). The training program was implemented three sessions a week for eight weeks. The indicators of balance, muscular endurance, cardio-respiratory endurance and upper body flexibility of the subjects were measured before and after training program. After eight weeks of Pilates training, there was a significant difference between the groups in the indices of cardiorespiratory endurance, muscle endurance, balance and vitamin D levels (P≤0.05). In terms of flexibility, it was observed that there is a significant difference between the two exercise groups in the outdoor with the control group and the Pilates exercise group at home with the control group (P≤0.05). Vitamin D levels in the outdoor Pilates group had increased significantly compared to the control group and the home exercise group (P≤0.05). However, no significant difference was observed between the control group and home practice. Probably, practicing Pilates at home and exposed to the sun can improve some indicators of physical fitness in women with multiple sclerosis. The results indicated a more effective role of exercise exposed to the sun on balance and muscle endurance. Also, Pilates exercise at home is recommended for MS patients due to the lack of special facilities, low cost, safe, and controllable intensity and duration.

Prediabetes is a risk factor in diabetes and therefore a healthy lifestyle is important to prevent pre-diabetes. This study aimed to determine the effect of endurance training on hepatic lipid metabolism in prediabetic C57BL/6 male mice. 21 mice were randomly divided into two groups. One was fed a normal diet (n=7, ND), and the other was fed a high-fat diet (n=14, HFD) for 12 weeks. After 12 weeks of initial maintenance, HFD s were subjected to a glucose tolerance test (GTT) and they were divided into two groups: exercise (EX) and pre-diabetes (preD). The training group trained for 45 minutes, 5 days a week, for 10 weeks. 24 hours before sacrifice, weighing and GTT were performed, and then the plasma and liver were obtained. The values of acetyl cocarboxylase beta (ACC2), carnitine palmitol transferase 1 (CPT1) and peroxisome receptor alpha were used to evaluate beta oxidation. Data interpretation was done using one-way analysis of variance with a significance level of p<0.05. In preD, weight, glucose, insulin, insulin resistance, and lipid profile experienced a significant increase compared to ND. In the EX, the mentioned factors were associated with a significant decrease (p < 0.01). CPT1 protein concentration, as a key factor of β-oxidation, decreased in preD the group, and ACC2, which is its inhibitor, increased. Endurance training improved fatty acid metabolism in the liver by reversing the expression process of these factors. Generally, preD caused changes associated with β-oxidation in the liver, while it seems that endurance training improved all. These findings show that regular exercise is probably an effective nonpharmacological approach for pre-diabetes.

Balance is a key factor for improving exercise performance and preventing sport-related injuries. The objective was to investigate the effect of transcranial direct current stimulation on dynamic balance after performing an exhaustive endurance task in normobaric hypoxia.Methods Fourteen endurance-trained men took part in this study. In three separate experimental sessions, after measuring the dynamic balance at baseline, participants were exposed to hypoxia for 30 min followed by one of the three montages of brain stimulation including 1) anodal stimulation of the M1 region, 2) anodal stimulation of the DLPFC region, and 3) sham stimulation for 20 minutes. Then, participants performed an exhausting cycling task at 60% of peak power output in hypoxia. Immediately after exhaustion, the dynamic balance was measured again. Two-way repeated measures ANOVA was used for statistical analysis. The results showed that after exhaustion under the hypoxic condition, the dynamic balance of the right leg in the DLPFC condition was significantly higher than the dynamic balance in the sham condition (p = 0.042). The results also demonstrated that the dynamic balance of the left leg after exhaustion in hypoxia was significantly higher than that of the sham condition (p = 0.042). We concluded that neuromuscular fatigue and exposure to the hypoxic condition could have a detrimental effect on dynamic balance. Also, it seems that anodal stimulation of the DLPFC area could have a positive effect on the dynamic balance after exhaustion under the hypoxic condition.

post-activation performance enhancement (PAPE) along with speed interval exercises (SIT) leads to the activation of neuromuscular mechanism and physiological adaptations in football players. In this regard, the aim of the present study was to evaluation of power and lactate indices of elite football players following a period of PAPE and SIT training. For this purpose, 20 elite football players of Pas Club (practice experience of 4.3 years, age 17±6 years, weight 70±5 kilograms, body mass index 21.60±2)  voluntarily participated in this research. The participants were divided into two groups of 10, squat-plyometric (SP) and control. The SP group followed the PAPE and SIT training program for 4 weeks during 2 sessions a week on Sundays: SIT training with 5 repetitions of 30 seconds of maximum effort with 5:00 active rest between each repetition was performed in the first week and in the fourth week active rest up to 3:30 decreased between each repetition. Thursdays: half-squat PAPE training with 40% of maximum strength to the point of exhaustion, then 7 minutes of active rest, then 2 times of 4 repetitions of half-squat with 80% of maximum strength, and immediately they performed 2 times of plyometric training, jumping over 5 obstacles of 70 cm, and after 2 minutes of rest Active, RAST test was performed. The roast test was performed in two stages before and after the test, and blood was drawn after 5 minutes. The analysis of covariance test showed that SP training group performed better than the control group in terms of metabolic and functional indicators, p≤0.0001. In connection with the lactate index, the results showed a very high increase in the training group in the pre-test stage, p≤0.0001. In the intragroup analysis, the results showed a better performance of the SP training group in lactate, maximum power, minimum power, average power, fatigue index in the post-test stage. But this difference was not significant for the control group except for the lactate index in other indices. According to the findings, it seems that PAPE guidelines with SIT can be considered an effective strategy for changing lactate metabolism and functional components of anaerobic power, in the specific preparation season before the competition, young athletes should be considered and trained athletes should train with maximum relative intensity to improve their capacities and physiological adaptations.

Physical activity in patients with diabetes can affect myocardial structure and function, the aim of this study was to evaluate the effect of 8 weeks of high intensity interval training (HIIT) on expression of PPARα and PGC1α proteins in the heart tissue of male Wistar rats with type 2 diabetes. In the present study, 28 male Wistar rats were randomly divided into four groups Control Healthy, Exercise Healthy, Diabetes Control, and Diabetes Exercise. After a period of high-fat diet and then after induction of diabetes, animals in Diabetes Exercise and Exercise Healthy groups performed the HIIT training protocol for 8 weeks and 5 sessions per week. 48 hours after the last training session, cardiac tissue was extracted and the levels of PGC-1α and PPARα proteins were assessed using Western blotting. Data were analyzed using one-way ANOVA and Tukey post hoc test at a significance level of P<0.05. The results showed that the expression levels of PGC-1α protein in the Diabetes Control group decreased significantly compared to the Control Healthy group (P=0.001) and increased significantly in the Diabetes Exercise group compared to the Diabetes Control group (P=0.001). Also, expression levels of PPARα protein in the Diabetes Control and Diabetes Exercise groups increased significantly compared to the healthy groups (P=0.001). Moreover, the amount of PPARα protein showed a significant decrease in the Diabetes Exercise group compared to the Diabetes Control group (P=0.001). HIIT exercises can probably play an effective role in regulating the PPARα/PGC1α signaling pathway and modulate the adverse changes caused by diabetes in this signaling pathway related to mitochondrial biogenesis.

It is very likely that the elderly will suffer from movement disorders and weak cognitive abilities after a stroke. Exercise can be a suitable strategy for rehabilitation in the elderly after stroke. Therefore, the purpose of this study was to investigate the effect of fall-proof exercises on cognitive abilities, balance and walking speed in elderly people with stroke. The current research was an interventional type. The research population included all stroke patients (334 people) in Yazd city, of which 24 male patients were selected by convenience sampling. The statistical sample was randomly divided into two equal experimental (12 people) and control (12 people) groups. The experimental group performed fall-proof exercises for 8 weeks, and the control group did not perform any intervention. In general, a training session included 10 minutes of warm-up and stretching, 15 minutes of strength training, 25 minutes of multisensory balance training (vision, vestibular, sensory-body), center of gravity control, and posture strategies. Cognitive abilities, balance and walking speed were measured before and after the exercises in both experimental and control groups. Multivariate covariance test was used for inter-group comparison and paired t-test was used for intra-group comparison. The results of the intergroup test showed that decision-making (p<0.001), sustained attention (p=0.003), cognitive flexibility (p<0.001), memory (p=0.005) Problem solving (p=0.001), balance (p<0.001) and walking speed (p=0.002) had a significant difference in the two experimental and control groups. The results of the intragroup test showed decision-making (p<0.001), paid attention (p<0.001), cognitive flexibility (p<0.001), memory (p<0.001), problem solving (p=0.003), balance (p>0.001) and walking speed (p=0.005) in the experimental group increased significantly in the post-test compared to the pre-test. fall-proof exercises have led to the improvement of cognitive abilities, balance and walking speed in the elderly with stroke. Considering the improvement of cognitive abilities, balance and walking speed, fall-proof exercises can be used in rehabilitation programs for elderly people with stroke.

It has been stated that ischemia preparation can have a positive effect on performance. The purpose of this study was to investigate the effect of ischemic preconditioning with different time intervals on the anaerobic performance of active female. 21 active female were selected and participated in the study. The study design was cross-over. Subjects were randomly assigned to three positions. The one experimental group performed, three sets of five minutes of vascular occlusion with five minutes’ rest between each set and immediately after the third occlusion, tests were taken. Two experimental group were exactly the same as the first group, except that between the third occlusion until the start of the tests, 10 minutes of rest are considered. In the control group, the elastic band was closed just behind the throat without any pressure on the thigh. Analysis of variance with repeated measurements was used to check the mean difference of the desired variables. The results indicated a significant increase in anaerobic power in Sargent jump in experimental group two compared to experimental group one and control (P<0.05). Regarding relative peak power in the Wingate test and anaerobic power with the Ergo jump test, there was no significant difference between the groups. According to the results of this research, the implementation of ischemia preconditioning, 10 minutes before the activity, with the intensity and duration applied in this research, has a greater effect on the vertical jump ability.

Alzheimer's (AD) is a chronic disease that destroys nerve cells, which eventually destroys the ability to do the simplest tasks. Alzheimer is caused by the accumulation of amyloid-beta (Aβ) peptides in the brain. Clusterin (CLU) interacts with Aβ and regulates its clearance from the brain. Studying the types of exercise activities and finding the best type is considered as a way to control Alzheimer's. The purpose of this research was to study the effect of six weeks of continuous aerobic training on CLU value, memory efficiency and exercise performance. 40 aged (11-month-old) male Wistar rats randomly divided into four groups of 10, including the patient training, 2: patient control, 3: healthy training, and 4: healthy control groups. The rats performed the relevant exercises training for six weeks by repeating five sessions per week. CLU was measured by ELISA method, memory and exercise performance were measured by new object recognition test and maximum exercise capacity test respectively. One-way analysis of variance and Tukey's post hoc test, were used for statistical analysis. The amount of CLU in the hippocampus in the patient training group was significantly reduced compared to the patient control group (P<0.05). Also, improvement of memory performance was observed in the patient training group compared to the patient control group (P<0.05) and exercise performance increased in the patient training and healthy training groups compared to the control group (P<0.05). According to the results of this research, continuous aerobic training during six weeks improves memory efficiency and exercise performance, as well as reducing clusterin in the hippocampus.

Objectives Type 2 diabetes is associated with an increase in levels of inflammatory factors in the systemic circulation, which causes impaired insulin function. Thus, the aim of this study was to investigate the impact of eight weeks of aerobic training on WISP1, tumor necrosis factor alpha (TNF-α) and insulin resistance index (HOMA-IR) in obese men with type 2 diabetes. Twenty-two obese men with type 2 diabetes (Age: 35.7± 4.9, BMI: 30.45± 2.35) volunteered to participate in the study and divided into two groups of training and control based on their fasting blood glucose levels. Subjects in training group performed eight weeks of aerobic training at intensity of 70 percent of maximum heart rate, three sessions per week and 45-50 minutes per session. Blood samples were collected before and 48 hours after training protocol to measure the blood factors assessed. Statistical analysis was done by two way analysis of variance, paired t-test and Pearson correlation at significant level of P<0.05. Eight weeks of aerobic training resulted in significant decreases in the serum levels of WISP1 (P=0.002), TNF-α (P<0.001) and insulin (P=0.001), fasting blood glucose (P=0.004), HOMA-IR (P=0.001), body weight (P<0.001), and body mass index (BMI) (P<0.001) in post-test compared to the pre-test . Moreover, there existed significant differences between training group compared to control group for serum levels of WISP1 (P=0.007), TNF-α (P=0.02) and insulin, (P=0.01), HOMA-IR (P=0.018), body weight (P<0.001) and BMI (P<0.001). Additionally, there were significant correlation between changes in serum levels of WISP1 following eight weeks of aerobic training and HOMA-IR (P=0.043). It seems that aerobic training improves insulin resistance in obese men with type 2 diabetes through modulating pro-inflammatory cytokines such as WISP1 and TNF-α.

Increased copeptin level is associated with increased inflammation and insulin resistance, and its concentration is significantly higher in the elderly than in the young. Therefore, the present study aimed to investigate the effect of 12 weeks of elastic band resistance training (EBRT) on the serum levels of copeptin, hs-CRP, and insulin resistance. Twenty-eight elderly women (age 74.04±4.69 years and body mass index 28.21±3.35 kg/m2) were selected based on the inclusion criteria and randomly assigned into one of two groups, exercise (n = 14) or control (n = 14) to participate in a 12-week (3d/wk) supervised EBRT. The exercise intensity was checked using the Borg scale at points 12 to 14. Pre-test measurements were taken before starting the training protocol, and post-test measurements were performed 48 hours after the last training session. Data were analyzed using two-way repeated-measures ANOVA. After 12 weeks of EBRT, no significant difference was observed in the anthropometric indices other than body fat percentage. A greater and significant decrease in body fat percentage was observed in the training group (p=0.023). Serum glucose levels did not change significantly, but serum insulin levels (p=0.035) and insulin resistance (p=0.045) decreased significantly. No significant change in serum levels of copeptin was observed after 12 weeks of training, but the reduction of hs-CRP serum levels was significant (p=0.037). Although the serum levels of copeptin did not change significantly after 12 weeks of EBRT, it seems that the reduction of insulin resistance and hs-CRP could be due to body composition improvement and indicate reduced inflammation and improved health in elderly women.