نشریه سوخت و ساز و فعالیت ورزشی
سال نهم شماره 1 (بهار و تابستان 1398)

The liver xα receptor (LXRα) participates in glucose metabolism. On the other hand, glucose transfer in liver by glucose transporter 2 (GLUT2). Therefore, this study was designed to examine the changes of LXRα, GLUT2 genes expression in liver and insulin resistance after 8 weeks of aerobic training in type 2 diabetic rats.

Eighteen male 8-weeks-old Wistar rats were selected as research sample. Diabetes was induced by nicotinamide and streptozotocin. Five days after diabetes induction, fasting blood glucose was measured using blood glucose strips. Rats with fasting blood glucose between 126-400 mg were selected as diabetic. Rats were divided into two groups: control and training. The training program was running with the speed of 10–25 m/min for 15-40 min/day, 5% slope, 5 days a week for 8 weeks.

Diabetes induction resulted in significant increase in body weight (p=0.001). Training group had higher muscle weight (p=0.001) and HbA1c (p=0.001) but lower glucose (p=0. 001), insulin (p=0.002) and insulin resistance index (p=0.002). LXRα and GLUT2 gene expressions were not different significantly.

It seems that 8 weeks aerobic training with 60-80% of vo2max can induce some positive metabolic changes in diabetic rats but did not induce any significant changes in LXRα and GLUT2 genes expression in liver tissue.

In this study the effects of a single training session of overweight men before and after a meal on serum acetylated ghrelin levels, daily energy intake and the exercise energy expenditure were compared.

In this  semi experimental study, 30 overweight men (Mean and SD age of 25.2±3.54 years, BMI 27.96±3.64 kg/m2, weight 83.2±5.8 kg) were randomized into three groups (n = 10) including before lunch training, post lunch training and control. Experimental groups performed eight weeks, three sessions/wk of aerobic training sessions, consisted of 25 to 40 min of treadmill running and/or cycling at maximal fat oxidation intensity, either an hour prior to or two hours after a meal. Exercise energy expenditure, daily caloric intake and fasting serum acylated ghrelin levels in response to a single exercise session were measured as data in both pre and post-test occasions.

A single training session either pre or post lunch meal increases serum acylated ghrelin level (P≤ 0/001), exercise energy expenditure (P≤ 0/001) and daily caloric intake (P≤ 0/001); indicating a compensatory energy intake which lowers the expected exercise-induced weight loss.However, pre meal exercise leads to more remarkable increases in exercise energy cost (P≤ 0/001) concomitant with an elevated fasting serum acylated ghrelin levels (P≤ 0/001).

If appetite suppression is the only goal for exercise, it seems that exercise training should be performed after meals, and if maximizing each session’s energy cost is the case, it is better to practice before meals.

This study aimed to examine the effect of aerobic exercise with and without BFR on blood lactate, cortisol and PGC-1α response in human skeletal muscle.

On two different occasions, five healthy untrained male subjects (mean±SE; age:  33.4±1.02 years, height: 173.9±4.02 cm, body mass: 79.64±4.69 kg), were required to perform (i) a BFR aerobic exercise at an exercise intensity of 40 % of VO2max; and (ii) similar exercise bouts without BFR (Ctrl). For each condition, baseline and 3 h post-exercise muscle biopsy samples (vastus lateralis) were performed for PGC-1α protein expression analysis. Venous blood samples were also collected at pre-exercise, immediately and 2 h post-exercise to measure changes in blood lactate and serum cortisol.

PGC-1α protein content was significantly higher (P < 0.05) at 3-h post-exercise with BFR compared with Ctrl. Blood lactate and serum cortisol did not significantly change from baseline to immediately after exercise and at 2-h post exercise.

Metabolic stimuli are not a mechanism to mediate cell signaling network responsible for mitochondrial biogenesis. However, the addition of blood flow restriction during aerobic exercise induces an increase in PGC-1α to regulate mitochondrial biogenesis.

In type 2 diabetes patients, the level of incretins is reduced. Incretins play an important role in glucose homeostasis. The aim of this study was to examine the effect of aerobic training along with Momordica charantia L on serum incretin levels in man with type 2 diabetes.

In this study, 36 men with type 2 diabetes (age 53.08±5.15 years, wight 78.08±6.53kg and BMI 26.22±1.2218 kg/square meters) were selected and were randomly divided into four groups (Control-Water, Control-Momordica charantia, Control-Training and Momordica charantia+Training). The training groups participated in a progressive aerobic training for eight weeks, three sessions a week (running with 40% to 70% of the reserved heart rate and for 15 to 45 min). The groups of Control-Momordica charantia and Momordica charantia+Training were provided 2000 mg of Momordica charantia (In 500 mg capsules) for eight weeks (Twice a day before breakfast and dinner). Two days before and after the protocol, blood samples were taken in fasting state.

The results showed that the GLP-1 I and GIP Increased significantly in all experimental group compared to the control group. (Respectively p=0.000 and p=0.000), Also a significant increase in GLP-1 in Momordica charantia+Training compared to the Momordica charantia and GLP-1 in Momordica charantia+Training compared to the Momordica charantia and Training. Other results showed a significant increase in GLP-1 and GIP in all experimental groups compared to pre-tes (p≤0.05).

It seems that aerobic training and Momordica charantia and combination of both, It improves the factors affecting glycemic control in men with type 2 diabetes.

Taurine is an antioxidant supplement. Therefore, the purpose of this study was to investigate the effect of short-term supplementation of two different dosages of taurine supplement on responses of some salivary antioxidant parameters of young men after an exhaustive aerobic activity.

Eight healthy non-athlete men (mean ± SD age 21.6 ± 1.7 yrs and VO2 max 62.62 ± 62.2 ml / kg / min) were randomly divided into two categories (3 Vs. 6 Gr/d) in two 7-day periods in the complement of taurine as cross-over, randomized and double-blinded. Saliva samples were collected in three occasions: before and after the supplementation period and immediately after exhaustive aerobic exercise. The subjects started the exhausting aerobic activity on ergometer was performed at 60 RMP and 20 watts, with, 20 watts added to the intensity every minute until the subject got exhausted.

The results showed that the SOD, after supplementation (in doses of 6 grams more than the dose of 3 g) and after exercise increased significantly compared with the pre-supplementation in both doeses (P<0.05). The activity level of POX and DPPH increased with supplementation and activity, but there was no significant difference between the two doses.

According to the research findings, it can be concluded that the short-term consumption of taurine supplementation by increasing antioxidant capacity will reduce the negative effects of free radicals as a result of intense aerobic exercise activities.

Unfavorable changes occur in the body composition and lipoprotein that are related to the loss of estrogen levels after menopause. The aim of this study was to investigate the effect of 12 weeks elastic band resistance training on mir-217 expression and cardiovascular risk factors in menopausal obese elderly women.

In this single blind randomized clinical trial (RCT), 49 elderly women with obesity (age 64.13 ± 3.68 years, fat percentage 45.4 ± 6.56 %, BMI 33. 1 ± 3.71 kg/m2) were divided into two groups: control (n=10) and training (n = 14). The training group performed elastic band resistance training for 12 weeks and three sessions per week for all major muscle groups. Forty eight hours before and after 12 weeks of intervention, a DEXA test was performed.

The results of the intergroup comparisons indicated a significant decrease in mir-217 expression and LDL levels and a significant increase in HDL in the training group compared to the control group (P≤0.05), whereas there was no significant difference in body weight, body mass index, fat percentage, total cholesterol and CRP (P≥0.05).

It seems that 12 weeks elastic band resistance training have been able to modulate and reduce the serum concentration of mir-217 in obese elderly women, which was associated with a decrease in LDL levels and increase levels of HDL. Although body mass index, fat percentage, total cholesterol and CRP Significant changes were not observed, which requires further investigation in this field.