SPORT PHYSIOLOGY (RESEARCH ON SPORT SCIENCE)
Year:2020 | Volume:12 | Issue:46|Papers Count:8

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) which caused COVID-19, is a pandemic that threatens human societies in many ways. It seems that the main strategy of managing coronavirus at present is to prevent infection. In addition to improving physical fitness, moderate-intensity exercise boosts the cellmediated and humoral immune system responses, especially in people with weakened immune systems who are at risk of coronavirus implications such as the elderly, obese people and those with chronic diseases. Therefore, performing regular exercise during life span can be considered as an effective strategy to prevent viral diseases such as COVID-19. On the other hand, home quarantine and non-use of public sports setting reduce physical fitness, circadian rhythm disturbances, sleep disturbances, depression, increased sedentary behaviors and impair the balance of energy received and consumed, which leads to a weakened immune system and a more severe risk of complications from COVID-19 disease. Performing moderate-intensity exercise at home during an outbreak can be an effective strategy in counteracting these complications. In addition, moderateintensity exercise is effective in improving the immune system and counteracting the effects of coronavirus directly by enhancing the immune system, antioxidant defenses and anti-inflammatory responses, and as well as indirectly by reducing anxiety, improving mood and modulating fat profile and insulin sensitivity.

CAP1 is one of the structural and functional important factors in fat tissues’ abnormalities in diabetic neuropathy (DN) state. The purpose of this study was investigation of the effects of endurance training on visceral adipose tissue levels of the CAP1 in male rats with diabetic neuropathy. 30 male Wistar male rats (260± 10 g) were randomly divided into three group of Control (C), Diabetic neuropathy control (DNC) and Diabetic neuropathy trained (DNT). Diabetes neuropathy induced by streptozotocin and was evaluated using behavioral pain tests. Also training group performed 6 week/ 5 sessions in week endurance training with moderate intensity. Forty-Eight hours after the last training session, subjects were anesthetized and visceral adipose tissue was removed immediately and by immunohistochemical analysis, the CAP1 protein level was measured. To assessing comparison between groups, ANOVA was used. The result of blood sugar and behavioral measurements demonstrated diabetic neuropathy model. Also, significant increase of the CAP1 levels was observed in adipose tissue of rats with diabetic neuropathy (P=0. 0001) however, training was not able to change this increased level of this protein in DN state so that significant difference was not seen between DNT and DNC groups (P=0. 246). The elevated levels of CAP1 may be a compensatory response to increase the glucose uptake, thermogenesis and abiogenesis. Also, the ineffectiveness of endurance training may be due to persistent hyperglycemia in the DNT group. However, the proof of these assumptions needs further studies.

One of the most important and prevalent consequences in elderly people is age-related muscular atrophy or Sarcopenia. Sarcopenia is associated with a significant reduction in muscle strength and mass. The purpose of this study was to investigate the effect of moderate and high intensity resistance training on miR-1, miR-206 expression and serum IGF-1 in 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 = 9), high intensity resistance training (n = 8) and the control group (n =8. 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, miR-1, miR-206 expression was measured using the by RT-PCR method in Soleus and FHL muscle and IGF-I in serum. The statistical analysis was performed using One Way ANOVA test with significance level of (P <0. 05). The results showed that in both resistance training group, miR-1 and miR-206 expression were significantly lower than those in control group and IGF-1 concentrations was significantly higher in both high and moderate resistance groups than control group (P <0. 05). High intensity resistance training was more effective for both miR-1 and miR-206 in FHL muscle and serumIGF-1. It seems that resistance training with moderate and high intensity can change the resting levels microRNAs related to muscular atrophy (miR-1, miR-206) and its target gene (IGF-1) in older rats and lead to the prevention of sarcopenia in older peoples.

Resistance training is an important component of the exercise program in most sports. However, low intensity resistance training with blood flow restriction can also increase muscle strength and local endurance. Therefore, the purpose of this study was to investigate the effect of low intensity eccentric resistance training with blood flow restriction on muscle volume and physical function of male soccer players. For this purpose, 40 soccer players were selected and randomly divided into four groups: traditional strength training (n=10), low intensity eccentric resistance training with blood flow restriction (n=10), intensified eccentric resistance training without blood flow restriction (n=10) and control (n=10). Before and after an eight-week training period, muscular strength and endurance tests were taken, and muscular hypertrophy according to ultrasound method was measured. ANOVA with repeated measures and Bonferroni post hoc tests were used to compare the variables between groups (P<0. 05). The results indicated that the experimental groups of eccentric training with a blood flow restriction and traditional training compared with the control group had a significant increase in upper strength test (P<0. 001). Also, there was no significant difference in the strength of the leg muscles between the groups. But, intra-group changes in all experimental groups showed a significant increase. Foot muscular endurance also showed a significant increase in all experimental groups. The results of the intergroup showed a significant increase between the traditional resistance training group and the eccentric resistant training group without blood flow restriction (P=0. 001) and between the group of the traditional resistance training and the eccentric resistant training group with blood flow restriction in the control group (P=0. 001). Also, there was no significant difference in upper endurance muscles (P=0. 18), quadruple muscle hypertrophy (P=0. 62) and hamstring (P=0. 053). These three training protocols eccentric resistance training program with and without blood flow restriction and traditional have the same effects on muscular strength, endurance, and hypertrophy in soccer players. However, athletes and coaches are advised to use resistance training with blood flow restriction because of its lower load use.

By considering the growing trend of obesity, along with metabolic disorders among children, especially insulin-resistance (IR), the present study aimed to evaluate the effect of aerobic-training on the levels of spexin, lipid-accumulation product (LAP), visceraladiposity (VAI), triglyceride-glucose (TyG) and McAuley indices among early-pubertal obese/overweight-girls. 32 obese/overweight-girls (age 9. 62± 0. 75 years-old, weight 49. 71± 9. 26 kg, BMI 25. 40± 2. 92 kg/m2, Tanner-stage 2-3) voluntarily participated in this study, who were assigned into interval-walking (n=12), continuous-walking (n=11) and control (n=9) groups. The subjects were trained three-times/week for two-months (30-min walk in the continuous and interval-groups with 60-75%HRmax and 70-85%HRmax, respectively). Spexin concentration was measured by ELISA method, and visceraladiposity and IR indices were calculated according to the equations. Factorial repeatedmeasured ANOVA was used for data analysis. Based on the results, the interaction-effect of time×group was statistically significant for the LAP (P=0. 007), VAI (P=0. 045), McAuley (P=0. 026) and TyG (P=0. 001), while it was insignificant for the spexin (P=0. 836). Regarding the control group, the LAP, VAI, and TyG significantly increased (P=0. 037, P=0. 046, P=0. 005, respectively) while a significant decrease happened for McAuley (P=0. 030). In the continuous-walking group, a significant decrease was observed in LAP (P=0. 002), and TyG (P=0. 002), while VAI and McAuley levels tended to decrease (P=0. 057) and increase (P=0. 071), respectively. In the interval-walking group, there was insignificant change in the LAP, VAI, TyG, and McAuley (P=0. 129, P=0. 660, P=0. 390, P=0. 357, respectively). The findings showed that the continuous-walking for eight-weeks could reverse the increase in visceral-adiposity and IR indices in the control group, irrespective of the changes in serum levels of spexin.

Considering the importance of glycemic balance adjustment in preventing cardiovascular complications of diabetes mellitus, regulation and control of blood glucose and insulin resistance is a very important issue. Including the protective factors that contrast with high blood glucose damage, can introduce glucagon-like peptides (GLP-1), Neuregulin-1 (NRG-1), and interleukin-33 (IL-33) that this factor can be affected by exercise. Therefore, the purpose of this study was to investigate the effect of 8 weeks of resistance and aerobic interval training on levels of GLP-1, NRG-1 and IL-33 in type 2 diabetic women. 30 diabetic women (51. 9 ± 5. 9 years) were randomly divided into 3 groups (n=10 in each group), resistance training, aerobic interval training and volunteer control. Aerobic interval training was performed with intensity of 50-75% MHR and resistance training performed with intensity of 30-75% 1RM, 3 sessions per week for 8 weeks. The values of GLP-1, NRG-1 and IL-33 were measured by ELISA kit. For data, analysis used ANCOVA (P<0. 05). The results of this study showed that resistance training compared to control group significantly increased (P = 0. 007) the GLP-1. Aerobic (P = 0. 037) and resistance training (P = 0. 001) compared to the control group and resistance training compared to aerobic training (P = 0. 008) significantly increased IL-33. NRG-1 changes were not significant in the two training groups. It seems that resistance training with positive regulation of GLP-1 and IL-33 has a better effect on glycemic control, blood glucose and ultimately improving cardiovascular conditions in type 2 diabetic women.

The purpose of this study was to investigate the effect of intake duration of curcumin supplementation on lipid peroxidation and antioxidant capacity of liver, heart and skeletal muscle during eight weeks of strenuous endurance training in male wistar rats. In this experimental study, 39 male wistar rats (age= 8 weeks; weight= 226. 76± 18. 64 g) after one week familiarization period, were randomly divided in to six group; Control, Curcumin, 48hrs Curcumin, Endurance, Endurance+Curcumin and Endurance+48hrs Curcumin. Endurance training (eight week, five sessions a week) carried out on rodent treadmill. Rats received curcumin supplement 30 mg/kg. BW by sub peritoneal injection (eight weeks, three sessions) or (last 48 hours, every 8 hours). GPX activity were measured using ELISA kits and MDA levels measured by spectrophotometric method. One-way ANOVA results showed that GPX activity of liver (P=0. 001) and heart (P=0. 034) were significantly lower, and MDA levels of liver (P=0. 001) and heart (P=0. 004) were significantly higher in endurance group in compared with control group. Also, GPX activity of liver in endurance+curcumin (P=0. 002) and endurance+48hrs curcumin (P=0. 001) groups were significantly higher than endurance group. MDA levels of liver (p=0/007) and heart (p=0/018) in endurance+curcumin group were significantly lower than endurance group and MDA level of heart in curcumin group was significantly higher than control. There were no significant differences between GPX and MDA activity of skeletal muscle. Based on our results, strenuous endurance training induced different oxidative stress responses in different tissues. On the other hand, curcumin supplementation during 8 weeks and even last 48 hours of strenuous endurance training, prevents oxidative stress and improves antioxidant capacity in liver and heart.

The purpose of this study was to compare the effect of eight weeks of resistance training and irisin injection on BDNF and spatial memory in male rats. 19 male mice (mean weight 18g and 5 weeks old) were randomly divided into control groups, sham, resistance training and irisin injection gruops. The resistance training program was conducted for eight weeks and three days each week. At the first week, the closed weights were 50% of the body weight of the rats and gradually increased to about 200% of their weight in the final week each session consisted of 3 repetitve 5 repetitions with 3 minutes of rest between turns and one minute between repetitions. Irisin injection was also performed three times a week. Elisa method was used to measure plasma irisin and BDNF and to evaluate spatial memory of Barns maze. Results showed a positive and significant correlation between irisin and BDNF (P = 0. 66, P = 0. 01). Also results showed irisin levels increased significantly in the training groups and irisin injection compared to the control group (P=0. 001, F=14. 25). This level was higher in the resistance training group than the irisin injection group, but the spatial memory (P=0. 658, F=0. 546) and BDNF levels (P=0. 635, F=0. 584) in the two groups did not have a significant effect. It can be concluded 8 weeks of resistance training and irisin injection did not have a significant effect on blood BDNF and spatial memory, but significantly increased the level of irisin.