Journal of Sport Biosciences
Year:2021 | Volume:12 | Issue:4|Papers Count:8

The aim of this study was to investigate the interactive effect of six weeks of endurance training and treatment of stanozolol steroid on changes of serum levels of ALT, AST and ALP enzymes in male healthy rats. 32 male Wistar rats (age: 12 weeks, mean initial body weight: 289± 16 g) were divided into four groups: placebo (P, n=8), exercise+placebo (E, n=8), exercise+stanozolol (ES, n=8) and stanozolol (S, n=8). ES and S groups received weekly intramuscular stanozolol injection (5mg/kg of body weight) while P and E groups received the same dosage of arachis oil as placebo. E and ES groups were submitted to a progressive endurance running program on a treadmill with the intensity of 70-75% VO2max for 6 weeks and 5 days per week. ALT, AST and ALP serum levels were measured by ELISA method. KS test was used to determine the normal distribution of data and Leven test was applied to determine the distribution of similar dispersion of groups. Data were analyzed by one-way ANOVA test at (P<0. 05) and Tukey post hoc test was used to determine within-group differences. ALT (P=0. 002) and AST (P=0. 001) changes were significant but ALP serum levels (P=0. 070) were not significant. According to the findings of this study, it can be stated that endurance training did not have a modulating effect on changes of liver enzymes due to stanozolol steroid consumption.

The aim of this study was to investigate the effect of 8 weeks of resistance training on serum levels of IL-15, IL-6, TNF-α and insulin resistance in elderly men with type 2 diabetes. 20 elderly men with type 2 diabetes (age: 72. 45 ± 4. 97 yr, weight: 79. 70 ± 12. 57 kg, BMI: 27. 4 ± 91. 07 kg) were selected and randomly assigned to two groups of resistance training (n=10) and control (n=10). Resistance training was performed for 8 weeks, 3 sessions/wk which included 8 movements in 3 sets with 10 repetitions at 70% 1RM. The paired t test and ANCOVA were used to analyze data at the significance level of 0. 05. Blood samples were collected at baseline and 48 hours following the last training session. Serum levels of IL-15, IL-6, TNFα , insulin and glucose were measured by ELISA method. The results of data analysis showed that 8 weeks of resistance training significantly increased serum levels of IL-15 and decreased levels of insulin, glucose and insulin resistance. However, it had no significant effect on serum levels of IL-6 and TNF-α . Based on the results of this study, it seems that resistance training may improve insulin resistance in elderly men with type 2 diabetes by increasing the levels of IL-15.

The aim of this study was to investigate the changes in creatine kinase, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase enzymes in recovery with two types of rolling foams after an exhaustive training session in male futsal players. The subjects of this study included 24 futsal players of Isfahan league (mean age of 26. 08 ± 2. 34 years and height of 179. 03 ± 3. 58 cm) who were randomly divided into three groups (soft foam, hard foam, control). Initially, the subjects performed exhaustive training; then, the soft foam and hard foam groups had the recovery protocol for 10 minutes with the interval of 45 seconds of pressure on the muscle and 15 seconds of rest while the control group rested. The mentioned enzymes were measured in four steps (baseline, immediately after training, immediately after recovery, and 24 hours after training). Data were analyzed using Shapiro-Wilk test, Levin test, and Mauchly test at a significance level of (P<0. 05). The results showed that although the activity of all the enzymes in the present study decreased significantly after recovery in both soft foam and hard foam groups, no significant differences were observed between these two groups in the changes of these indicators (P>0. 05). All changes in the enzymes except for lactate dehydrogenase were significant 24 hours after the training for both soft foam and hard foam compared to the control group (P<0. 001). The active recovery method with rolling foam reduces the indicators of muscle damage more and more compared to the inactive recovery and athletes will be back to baseline faster.

Beta-alanine is a supplement that reduces fatigue. This supplement can improve a person's record and heart rate. The aim of this study was to investigate the effect of consuming different amounts of beta-alanine supplement on performance indicators following a 1-km time trial test in female athletes. 30 female athletes in Shiraz (mean age 23+4 years and mean weight 58+7 kg) were randomly divided into two groups of high-dose supplement and low-dose supplement. Subjects consumed placebo (orange syrup) in the first week; in the second week, the first group consumed a low dose of beta-alanine supplement (0. 03 g/kg of body weight) and the second group consumed a high dose of beta-alanine supplement (0. 1 g/kg of body weight). Then, they performed a one-kilometer time trial test. The variables of record, heart rate and fatigue perception were measured before, immediately, 4 minutes and 10 minutes after the test. The results of analysis of variance with repeated measures and mixed analysis of variance showed a significant decrease in the perception of fatigue following beta-alanine consumption in both high and low dose groups compared to the pretest (P=0. 001). Record decreased significantly in the high dose group (P=0. 023) and the record changes were not significant in the low dose group (P=0. 131). Heart rate significantly changes in both high and low dose groups compared with the pretest (P=0. 001). The results showed that even at low doses, betaalanine reduced heart rate and fatigue perception while high doses of betaalanine only improved the record.

Aerobic training can have an important role in delaying fatigue by increasing lactate transporters. However, changes in monocarboxylate transporters (MCTs) during detraining and the effect of, so-called, shock training on the maintenance of training adaptations during detraining have remained unknown. Therefore, the aim of this study was to investigate the effect of endurance training, detraining and shock training on the endurance performance and protein levels of monocarboxylate transporters (MCT1 and MCT4) in gastrocnemius muscle of male rats. In this experimental study, 24 male rats (247. 05± 6. 75 g) were assigned to four groups: control, endurance training, endurance training + detraining and endurance training + shock training. The running program on a treadmill was performed for 12 weeks (5 sessions a week with the intensity of about 85% of VO2max in the last week). The detraining/shock training protocol (one session per week, for 40 minutes at a speed of 20-30 m/min) was applied from 10 th to 12 th week. Levels of MCT1 and MCT4 were measured by the ELISA method. Endurance performance was assessed using exhaustive test. The level of MCT1 of gastrocnemius muscle in the endurance training group was higher than the control group (P=0. 001). However, there were no differences in the level of MCT1 among detraining, endurance training (P=1. 000) and shock training (P=0. 998) groups. Endurance training, detraining and shock training did not significantly change MCT4 level of gastrocnemius muscle (P=0. 148). Detraining visibly decreased endurance performance compared with the endurance training group (P=0. 001). Despite the significantly decreased performance of the shock training group compared with the endurance training group (P=0. 001), shock training prevented detraining induced performance loss (P=0. 006). Endurance training increases the MCT1 level of the gastrocnemius muscle. This increase is not influenced by detraining or shock training. However, it seems that shock training can ameliorate the loss of endurance performance caused by detraining.

Diabetes, as a chronic metabolic disorder with a high prevalence, highlights the importance of ongoing research and the need for new methods to prevent and treat this epidemic disease. The aim of this study was to evaluate the changes in fibrosis and apoptosis of heart tissue in diabetic rats following two types of aerobic and interval training with astaxanthin supplementation. 35 male rats were randomly divided into 7 groups after induction of diabetes: diabetes control, diabetes sham, diabetes+aerobic training+supplement, diabetes+interval training+supplement, diabetes+interval training, diabetes+aerobic training, diabetes+supplement. Interval training was performed on the treadmill for 8 weeks, 5 sessions per week with an intensity of 80% vo2max and aerobic training was performed on a treadmill with an intensity of 65-75% Vo2max. The protein contents of Cas3, COL4a1 and fibronectin were measured by Western blotting technique. COL4a1 protein content in both training and combined groups and supplement group showed a significant decrease compared with the control group. Also, the protein contents of Cas3 and fibronectin in the combined and aerobic groups significantly reduced compared to the control group, but there was no significant difference in the content of these proteins between the supplement and interval groups compared to the control group. It seems that the synergistic effects of training with different intensities along with astaxanthin supplementation prevent the upward trend of apoptosis and fibrosis in the heart tissue of diabetic rats and its subsequent complications such as diabetic cardiomyopathy.

Considering the importance of preventing heart disease and conflicting information about the effect of exercise training on glutathione peroxidase and catalase gene expression, the aim of this study was to investigate the effect of four training methods on glutathione peroxidase (GPX) and catalase (CAT) expressions in heart tissue of rats for 8 weeks. 40 male Wistar rats (age: 8 weeks) were randomly divided into 5 groups including control, moderate intensity aerobic training, high intensity aerobic training (HIT), high intensity interval training (HIIT) and moderate intensity swimming training (MIST). To analyze the data, one-way ANOVA and Tukey test were used. The results showed a significant increase in the gene expressions of GPX and CAT following all four training protocols compared to the control group (P=0. 001). Also, a significant increase in GPX gene expression was observed in HIIT and HIT groups compared to MIT and MIST groups (P=0. 001). There was a significant increase in CAT expression in MIST group compared to MIT and HIIT groups (P=0. 001 and P=0. 030, respectively) and in HIT group compared to MIT and HIIT groups (P=0. 001 and P=0. 041). There was also a significant difference between MIT and HIIT groups (P=0. 001). All four training methods were able to improve the antioxidant system, causing favorable changes in the heart tissue of Wistar rats. It seems that HIT, HIIT and MIST make the body more resistant to the oxidative stress and have a more favorable effect on the heart tissue by creating a beneficial adaptation in the antioxidant system.

Aging is often associated with a progressive loss of muscle strength and an increase in fat mass. High intensity interval training may improve muscle strength, but remains largely unstudied in elderly participants. Therefore, the aim of this study was to investigate the effect of 8 weeks of low-frequency high-intensity interval training and L-citrulline supplementation on myostatin, aerobic power, muscular strength and endurance and body fat percentage in elderly men. 30 inactive elderly men were selected and randomly divided into three groups: high-intensity interval training (HIIT), citrulline (CIT) and high-intensity interval training+citrulline (HIIT+CIT). HIIT protocol was performed for 8 weeks and 2 sessions per week that included 30 seconds of cycling on ergometer (intensity of 85-90% HR reserve). CIT supplement was consumed (6 g-dose) every other day. Oneway ANOVA test was used. Results showed significant decreases in myostatin in HIIT+CIT group compared with the CIT group and in body fat percentage in HIIT+CIT and HIIT groups compared with the CIT group. Aerobic strength and power significantly increased in HIIT+CIT and HIIT groups compared with the CIT group. HIIT+CIT group showed a significant increase in muscular endurance compared to the CIT group. In conclusion, HIIT alone and combined with L-citrulline improved muscular strength and muscle mass and aerobic performance in inactive elderly men. Therefore, low-frequency HIIT+CIT can be considered as an effective method to prevent or reduce sarcopenia in the elderly.