نشریه مطالعات کاربردی علوم زیستی در ورزش
پیاپی 23 (پاییز 1401)

Hyperglycemia occurring in the diabetic condition can cause apoptosis via the mitochondrial pathway with higher cell death protein expression. Probiotics are viable microorganisms which confer health benefits to the host and have anti-diabetic and antioxidant effects. Also, there are some evidences that exercise may affect the signaling pathways of skeletal muscle apoptosis. The aim of this study was to examine the aerobic exercise training and probiotic supplementation effects on blood glucose levels and caspase-3 gene expression of the soleus muscle in diabetic rats-induced by streptozotocin.

 40male Wistar rats (weight: 250-270 gr; age: eight weeks) were selected and divided into five groups: control+normal (N), control+diabetic (CD), diabetic+probiotics (SCD), diabetic+aerobic training (TD), and TD+probiotics (STD). Rats were made diabetic using streptozotocin (45 mg/kg). The rats in the training groups aerobically exercised using a treadmill at intensity of 60-65% of maximum speed for five weeks and five days per week and received probiotics (2 gr) in drinking tap water (supplemented groups). 48 hours after the last training session, the animals were sacrificed, then the soleus muscle was dissected to evaluate the gene expression of caspase-3 (using the Real Time PCR) and plasma glucose (by the glucose oxidase method). T-test, one-way ANOVA and Scheffe’s post hoc tests were applied for statistical analysis at significance level of p≤0.05.

The results indicated that fasting blood sugar was significantly lower in the TD+probiotics group compared to the other groups (p=0.008). On the other hand, gene expression of caspase-3 was a significantly decreased in diabetic+aerobic training and TD+probiotics (p=0.01) groups.

It appears that aerobic exercise training with the use of probiotics prevents apoptosis in the muscle with the down-regulation of blood glucose.

Resistance training with blood flow restriction stimulates the response and release of anabolic hormones and increases hypertrophy in restricted muscles, however, the effect of this training method on adjacent non-restricted muscles has not been studied well. The aim of this study was to evaluate the effect of 4 weeks of resistance training along with blood flow restriction on anatomical cross-sectional area (CSA) of adjacent non-restricted muscles in active young men.

Sixteen young men aged 25-30 years old were randomly divided into two groups (n=8) high-intensity resistance training (HIRT) and low-intensity resistance training with blood flow restriction (L-BFR). Both groups performed bench press and squat exercises three sessions per week during four weeks. In HIRT group, three sets of 10 repetitions (75%1RM), and in the L-BFR, four sets of 30, 15, 15 and 15 repetitions (30%1RM) was performed during every exercise. For L-BFR group, the restriction pressure was considered as 50% resting atrial occlusion pressure (AOP) at the beginning of the exercises and this pressure gradually was increased to 80% AOP during four weeks. At the beginning and 72 hours after the last training session, the CSA of triceps brachii, pectoralis major, quadriceps and gluteus maximus were calculated by MRI. Data were analyzed by paired sample t-test and analysis of covariance (ANCOVA) test at the significance level of p<0.05.

Four weeks of training lead to significant increase in the cross-sectional area of triceps brachii, quadriceps, pectoralis major and gluteus maximus in the HIRT (4%, 7.5%, 10%, 10% respectively) and L-BFR (11%, 12%, 18%, 22% respectively) groups.

It seems that the anabolic effects caused by blood flow restriction exercises are not limited locally and can be transferred to the adjacent muscles involved in the exercise that are not directly affected by the blood flow restriction.

Increasing active muscle oxygen availability can affect exercise performance, therefore the oxygen supplementation can be considered as important factor. This study aimed to investigate the acute effect of oxygen inhalation before karate competition on buffering capacity recovery and performance of male professional karate.

Eight national karate athletes with weight categories 75 (BMI: 23.45±1.24 kg/m2) and 85 (BMI: 25.93 ± 1.97 kg/m2) Kg participated in this study as a double-blind cross design and further divided into two groups of oxygen (10 minutes, 40% of oxygen concentration,10 liters per minute) and natural (mask attached to a normal air cylinder). Thirty minutes before, immediately and 20 minutes after the three-minute competition, venous blood sampling was obtained and lactate was measured enzymatically by Kubas Mira autoanalyzer. Moreover, the acidity (PH), oxygen saturation (O2-SAT), pressure of carbon dioxide (PCO2) and bicarbonate (HCO3- ) were analyzed by blood gas analyzer. Heart rate and the number of strokes were also measured to assess performance. Repeated measures two way- ANOVA and LSD test was used to analyze the data at p≤0.05 level.

The result indicated significantly lower reduction of lactate and higher amount of HCO3-  in the oxygen than to non-oxygen group during the three evaluation times (p=0.001). Moreover, higher acidity, lower PCO2   and O2-SAT, as well as lower average heart rate were observed in the oxygen than to non-oxygen group but it wasn’t significant (p0.05<) Oxygen inhalation significantly improved hand and foot stroke performance in the oxygen compared to non-oxygen group (p=0.004).

Acute inhalation of oxygen before karate competition does not seem to have a significant effect on the buffer capacity recovery of karate athletes, although it could improves athlete performance in the same competition.

Since many cellular and molecular pathways involve in diabetes are unknown, the aim of the present study was to study the effects of aerobic exercise on glycogen stores in pre-diabetic rats.

Twenty-one homogenous male C57BL/6 mice were randomly divided into two groups including Mice fed standard diet (n=7) and Mice fed high fat diet (n=14). The mice were fed for 12 weeks and then the pre-diabetic conditions of the mice were assessed by fasting glucose and glucose tolerance tests. After confirmation of pre-diabetic conditions, mice fed a high-fat diet were divided into two groups as high-fat-sedentary diet, and high-fat diet-aerobic exercise. Mice in the training group were trained on a treadmill for 10 weeks, five days a week for 45 minutes in every session. Twenty-four hours after the last training session, the rats were killed and blood was drawn from the rats’ hearts. Liver tissue was isolated and frozen to measure glycogen synthase gene expression (RT-Real time PCR) in liquid nitrogen.  The independent t-test and one-way analysis of variance were used for statistical analysis at the p<0.05 level.

The glycogen synthase levels in the aerobic exercise group were higher than the prediabetes group and had a significant effect on glycogen synthase expression (p=0.001). Also, liver glycogen showed significantly increase (p=0.001) in the amount of hepatic glycogen stores in the exercise group compared to the prediabetes group.

Aerobic exercise can lead to the improvement of the condition from pre-diabetic to healthy condition.

The mitochondrial biogenesis-regulating protein of the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) acts as a major signaling pathway for controlling of mitochondrial metabolism. Meanwhile, a transcription factor namely nuclear factor erythroid 2-related factor 2 (Nrf2) is recognized that also associated with PGC1α activation, and it has been shown to some extent to the pathway of one of these two transcription factors can affect the other. The aim of this study was to evaluate the effect of eight weeks of resistance training a long with coenzyme Q10 supplementation on Nrf2 and PGC-1α levels in male Sprague-Dawley rats.

In this experimental study, 36 rats were randomly divided into six equal groups including resistance training, two resistance training and Q10 supplement (200 and 300 mg/kg/body weight), two supplement (200 and 300 mg/kg/body weight) and control group. The all supplements were applied as a gavage to the exercise-supplement and gavage supplement groups. Resistance training consisted of three sessions and five repetitions which were performed three days a week for eight weeks. One-way analysis of variance and Tukey tests at the significant level of p<0.05 were used to extract the results.

Nrf2 and PGC-1α expression increased significantly in resistance training and resistance training+supplement (200 mg/kg) groups (p<0001), while in resistance training group+supplement a dose of 300 mg/kg (p<0.07) and two groups of supplements (p<0.09) no significantly changes were observed.

Due to the additive effect of resistance training combined with Q10 supplementation (a dose of 200 mg/kg) in improving Nrf2 and PGC-1α; it can be considered as a effective method in mitochondrial biogenesis.

Non-alcoholic fatty liver disease is a liver inflammation caused by excessive accumulation of fat in the liver tissue. This condition could impair the normal functioning of liver tissue, such as liver failure or cirrhosis. Exercise and physical activity can potentially be considered as an effective method in reducing liver fat. The aim of this study was to investigate the effect of high-intensity interval training (HIIT) on serum levels of fibroblast growth factor-21, aspartate aminotransferase, alanine aminotransferase, lipid profile and insulin resistance in women with fatty liver.

In this quasi-experimental study, 28 women with non-alcoholic fatty liver disease participated as an available sample and randomly divided into two groups of control (n=14) and exercise (n=14). HIIT program were performed for eight weeks, three times a week and each session was conducted for 60 minutes. Dependent variables were done 72 hours before the first and after the last training session. Data were analyzed by paired and independent t-tests at the significant level of p<0.05.

After eight weeks of HIIT, fibroblast growth factor-21 (p=0.03) and high density lipoprotein cholestrol (p=0.01) significantly increased. On the other hand, aspartate amino transferase (p=0.04), alanine amino transferase (p=0.03), low density lipoprotein cholestrol (p=0.01) and triglyceride (p=0.005) significantly decreased while insulin resistance remained unchanged (p=0.24).

By performing HIIT, it can be expected that the risk factors in patients with non-alcoholic fatty liver disease could be improve.

Caffeine is a widely used physiological stimulant worldwide that athletes use to increase strength and delay fatigue, which is currently available in the form of energy drinks and dietary supplements. Therefore, the present study was conducted to investigate the effect of fatigue and caffeine supplementation on balance and some physical and skill fitness characteristics of young football players in Sarayan city.

In this way, 24 football players with an age range of 18 to 25 years, at least four to five years of continuous activity were purposefully selected and randomly divided into experimental and control groups. All participants firstly performed the dynamic balance, explosive power (Sargent jump test), agility (Illinois test), and Moore–Christian shooting & passing performance test. Further, the experimental group received caffeine capsules (six mg/kg/day) and the control group received starch capsules (six mg/kg/day). Moreover, the Bangsbo protocol was performed with 42 of two-minute cycles to create simulated fatigue in football players. After the implementation of the fatigue protocol and similar to the pre-test, all the tests were repeated. The results were extracted using independent and dependent t-test at the significant level of p≤0.05.

Muscle fatigue significantly decreasing effect on dynamic balance (p=0.001), vertical jump (p=0.001), shooting skill (p=0.001), but no significantly changes were observed on agility (p=0.39) and passing skill (p=0.11), while caffeine had no effect on these changes.

Consumption of six mg per kg of body weight caffeine may not have been effective and therefore, it seems that football players can improve their physical fitness characteristics from higher doses of caffeine instead of lower doses to be more effective. Further studies are needed to reach a definitive conclusion.

Arsenic exposure could likely lead to hepatic apoptosis and metabolic disturbances and high intensity interval training (HIIT) as well as curcumin supplementation seems to improve this condition. The aim of the present study was to investigate the effects of HIIT and curcumin supplementation on hepatic nuclear factor erythroid 2-related factor 2 (NRF2) and caspase-3 as well as blood total antioxidant capacity (TAC), glucose, triglyceride (TG), and high density lipoprotein cholesterol (HDL) in rats exposed to arsenic.

During the experimental study, 48 male rats were randomized into six groups of arsenic-HIIT (HIIT), arsenic-curcumin (curcumin), arsenic-HIIT-curcumin (concomitant), arsenic, ethanol control, and normal control. Arsenic and curcumin (5 and 15 mg/bw/day respectively) were consumed by gavage method. HIIT performed six weeks, five d/w, 60 min/session, consisted of running bouts (four min) at 85-90% of vVo2max with two min active rest intervals. The data were measured using colorimetry and Wester blotting and were analyzed by one-way ANOVA at the p<0.05.

Hepatic caspase-3 as well as blood glucose and TG were significantly higher, and blood TAC and HDL levels were lower in arsenic group compared to normal control (p=0.001 under any circumstances). However, blood HDL, glucose and TAC in all three groups of HIIT, curcumin and concomitant as well as liver caspase-3 just in concomitant group had not significant difference as compared to control group (p>0.05). Additionally, hepatic NRF2 were elevated to levels even higher than control group in curcumin and concomitantc groups (p=0.001).

Although the up-regulated blood TG-induced by arsenic could not restore with HIIT, curcumin or concomitant interventions, however, three interventions efficiently restore the elevated blood glucose and also the lowered HDL and TAC. Moreover, increased hepatic caspase-3 was only corrected with concomitant intervention, while only curcumin could restore the lowered levels of hepatic NRF2 induced by arsenic.

The carbohydrate mouth rinse (CMR) has been proposed as a strategy to boost athletic performance. The present study aimed to investigate the effect of CMR on the electrical activity of the quadriceps muscle during a sub-maximal cycling task within different phases of the menstrual cycle in female athletes.

Ten active females came to the laboratory on five different times. In the first session, peak power output was measured and during the second to fifth visit (5th and 12th  days of the follicular phase and 17th and 22th days of the luteal phase) each subject completed a one-hour cycling task at 65% of peak power output under either CMR or placebo condition in each phase. Before and during every 15 minutes of the trial, participants rinsed their mouths with carbohydrate or placebo solution. Lactate, and blood glucose were measured before and immediately after the trial. Moreover, during the task, heart rate and rating of perceived exertion also were recorded every 10 minutes, and the electrical activity of the Rectus Femoris, Vastus Lateralis, and Vastus Medialis muscles was recorded every 15 minutes. A repeated measures ANOVA and Bonferonni tests were used for statistical analysis at the p<0.05 significant level.

The electrical activity of the Vastus Lateralis muscle at times 45 (p=0.04) and 60 (p=0.04) and, the Rectus Femoris muscle at time 45 (p=0.01) in the follicular phase under CMR condition was significantly higher than the same times in the luteal phase.

These results indicated the possible interference effect of menstrual phases on CMR-induced changes in muscular performance. It seems that maintaining the electrical activity of the quadriceps muscle under CMR condition in the follicular phase as compared to the luteal phase could be related to sex hormone levels.