A High intensity Interval training (running and swimming) and resistance training intervention on heart rate variability and the selected biochemical factors in boys with type 1 diabetes.

OBJECTIVE: The purpose of this research is to investigate the effect of High Intensity Interval Training and Resistance training (HIITR) on heart rate variability (HRV), blood glucose, and plasma biomarkers levels in adolescents with type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: 24 boys with T1D (FBS: 274.66 ± 52.99, age: 15.2 ± 1.78 years, and BMI = 19.61 ± 1.11) and 12 healthy boys (FBS: 92.75 ± 5.22, age: 15.08 ± 1.67 years, and BMI = 20.26 ± 2.66) were divided into three groups: Diabetes Training (DT, n = 12), Diabetes Control (DC, n = 12), and Healthy Control (HC, n = 12). HRV (24 h) was computed in time and frequency domains, anthropometric, biochemical parameters at rest, and aerobic capacity (VO2peak) obtained during a graded exercise testing (GXT). All variables were evaluated at the baseline and following 12 weeks of exercise training, done 3 days weekly. The statistical method used for data analysis was analysis of covariance (ANCOVA) test. RESULTS: HRV, Hemoglobin A1c (HbA1c) and Fasting blood sugar (FBS), VO2peak, norepinephrine (NEP), and HDL-C indicated significant differences between both T1D groups compared to HC at baseline (p < 0.001). BMI, LDL-C, TC, and TG parameters were similar in all groups. HRV parameters, VO2peak and HDL-C, and NEP were significantly improved by exercise training, and HbA1c and FBS levels were significantly reduced (p < 0.001). There is a negative and significant correlation between LF/HF Ratio Difference (post-test minus pre-test) and VO2Peak Difference variables (post-test minus pre-test) (p < 0.001). CONCLUSIONS: The present study suggests the importance of early screening for CVD risk factors in adolescent males with T1D. Also, it was revealed HIITR training compared to other training patterns, and cardiovascular health improves via enhancement of autonomic modulation, VO2peak, plasma lipids, and catecholamine levels.

Developing First Native Regression Equations to Predict of Cardiorespiratory Fitness in Healthy Boys.

Background: Cardio-respiratory fitness (CRF) is a strong predictor of overall health and is considered a key physiological measure in health care settings. Maximal oxygen uptake (VO2max) is considered the gold standard for measuring CRF. Non-exercise VO2max regression equations provide a safe, simple and relatively accurate means of measuring CRF in the general population. This study aimed to develop first native regression equations to predict of CRF without exercise test in Iranian healthy boys. Methods: Laboratory gold standard CRF and anthropometric variables were measured in 597 healthy boys (8-17 yr) in Hmadan City, Iran in 2019. Multiple regression analysis was used to generate CRF regression equations. Cross validation of the CRF regression equations was assessed using PRESS statistics, Pearson correlation, Bland-Althman plot and paired t-test. Results: CRF regression equations based on age, body mass index, body fat and resting heart rate were developed (R2=0.602 - 0.639, SEE = 3.42 - 3.73 ml/kg/min). PRESS statistics show that, shrinkage of the R2 (0.04 - 0.06) and the increment of SEE (0.18 - 0.25 ml/kg/min) is minor. There was strong correlation (R =0.847-0.883, P<0.001) and no significant difference (min diff= 0.09-0.18 ml/kg/min, P>0.05) between measured and predicted CRF. The Bland-Altman plot illustrates the strong agreement between the two values. Conclusion: We introduced simple and satisfactorily accurate CRF regression equations based in healthy boys. Prediction of CRF of the boys by regression equations would provide a simple tool for assessing cardiorespiratory fitness in large studies including Iranian boys.

Investigation of the effect of 8 weeks of high-intensity interval training and berberine supplementation on some echocardiography and electrocardiogram indices following myocardial ischemia-reperfusion in rats.

BACKGROUND: Myocardial ischemia leads to left ventricular (LV) dysfunction and cardiac arrhythmia. The present research was conducted with the aim to explore echocardiography changes and electrocardiogram parameters of the hearts of rats with ischemia-reperfusion injury (IRI). METHODS: The study subjects included 50 male Wistar rats) 8-10 weeks), which were divided into 5 groups (1: trained, 2: supplemented, 3: combined (training and supplementation), 4: sham, and 5: control). High-intensity interval training ý(HIIT) was performed for 8 weeks, 5 sessions per week. Rats belonging to groups 2 and 3 received 10 mg/kg berberine. Finally, after 48 hours, electrocardiogram and echocardiography were performed on all rats. Moreover, myocardial ischemia was performed by descending coronary artery ligation for 30 minutes. RESULTS: There were significant differences between the 5 groups in terms of the volumes and dimensions of LV end-systolic dimension (LVSD), LV end-diastolic dimension (LVDD)ý, fractional shortening cardiac output, ejection fraction (EF), stroke volume (SV), ventricular tachycardia (VT), and ventricular ectopic beats (VEBs) episodes, duration of VTs, and ECG parameters (P ≤ 0.05). CONCLUSION: Berberine supplementation and HIIT, as preconditioning agents, can possibly prevent the elevation of EF and fractional shortening, the reduction of cardiac output and SV, and arrhythmia improvement after myocardial IRI. Finally, these changes result in increased LV function and decreased mortality in rats with myocardial IRI.

Endurance exercise improves avoidance learning and spatial memory, through changes in genes of GABA and relaxin-3, in rats.

Different exercise patterns, neurotransmitters, and some genes have numerous effects on learning and memory. This research aims to investigate the long-term effects of submaximal aerobic exercise on spatial memory (SM), passive avoidance learning (PAL), levels of serum relaxin-3, gamma-aminobutyric acid (GABA), RLN3 gene, and glutamic acid decarboxylase (GAD65/67 genes) in the brainstem of adult male Wistar rats. Fifty male Wistar rats were randomly divided into five groups: aerobic exercise groups, performed on a treadmill running (TR), for 5 weeks (Ex5, n = 10), 10 weeks (Ex10, n = 10), involuntary running wheel group for 5 weeks (IRW5, n = 10), sham (Sh, n = 10) and control (Co, n = 10). Consequently, SM, PAL, serum relaxin-3, GABA, and GAD65/67 and RLN3 genes were measured by ELISA and PCR. Ex5, Ex10 and IRW5 improved significantly SM (p ≤ 0.05), PAL (p ≤ 0.001) and decreased significantly relaxin-3 (p ≤ 0.001). RLN3 in the brain also decreased. However, it was not significant. GABA and GAD65/GAD67 increased significantly (p ≤ 0.05) in Ex5, Ex10 compared to Sh and Co. Aerobic exercise enhanced SM and PAL in Ex compared to Co and Sh. However, duration and type of exercise affected the level of enhancement. The serum relaxin-3 and RLN3 gene displayed reverse functions compared to GABA and GAD65/67 genes in Ex. Therefore, the changes of neurotransmitters in serum relaxin-3, GABA, and their genes: RLN3 and GAD65/67 respectively, influenced learning and memory meaningfully.

Preconditioning Effect of High-Intensity Interval Training (HIIT) and Berberine Supplementation on the Gene Expression of Angiogenesis Regulators and Caspase-3 Protein in the Rats with Myocardial Ischemia-Reperfusion (IR) Injury.

OBJECTIVE: It has been shown that angiogenesis is a desirable treatment for patients with ischemic heart disease. We set out to investigate the impact of high-intensity interval training (HIIT) and berberine supplementation on the gene expression of angiogenesis-related factors and caspase-3 protein in rats suffering from myocardial ischemic-reperfusion injury. METHODS: Fifty rats were divided into the following groups: (1) trained, (2) berberine supplemented, (3) combined, and (4) IR. Each cohort underwent five sessions of HIIT per week for a duration of 8 weeks followed by induction of ischemia. Seven days after completion of reperfusion, changes in the gene expression of angiogenesis-related factors and caspase-3 protein were evaluated in the heart tissue. RESULTS: We observed a significant difference between four groups in the transcript levels of vascular endothelial cell growth factor (VEGF), fibroblast growth factor-2 (FGF2), and thrombospondin-1(TSP-1) (p ≤ 0.05). However, the difference in endostatin (ENDO) levels was not significant among the groups despite a discernible reduction (p ≥ 0.05). Moreover, caspase-3 protein and infarct size were significantly reduced in the intervention groups (p ≤ 0.05), and cardiac function increased in response to these interventions. CONCLUSION: The treatments exert their effect, likely, by reducing caspase-3 protein and increasing the expression of angiogenesis-promoting factors, concomitant with a reduction in inhibitors of the process.

Aerobic training and L-arginine supplement attenuates myocardial infarction-induced kidney and liver injury in rats via reduced oxidative stress.

INTRODUCTION: The aim of the present study was to determine the effect of exercise training and l-arginine supplementation on kidney and liver injury in rats with myocardial infarction (MI). MATERIAL AND METHODS: Four weeks after MI, 50 male wistar rats randomly divided into five followed groups: sham surgery without MI (Sham, n=10), Sedentary-MI (Sed-MI, n=10) 3: L-Arginine-MI (La-MI, n=10) 4: Exercise training-MI (Ex-MI, n=10) and 5: Exercise and L-arginine-MI (Ex+La-MI). Ex-MI and Ex+La-MI groups running on a treadmill for 10 weeks with moderate intensity. Rats in the L-arginine-treated groups drank water containing 4% L-arginine. Tissues oxidative stress and kidney and liver functional indices were measured after treatments. RESULT: Urea as a kidney function indexes, increased in Sed-MI group in compared to sham group and decreased significantly in Ex-MI and Ex+La-MI groups. The level of catalase (CAT) and glutathione stimulating hormone (GSH) of kidney were significantly lower in the MI-groups compared with the Sham group and kidney Malondialdehyde (MDA) levels increased after MI and significantly decreased in response to aerobic training and L-arginine. As well as, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as liver injury indices, increased in MI-groups and decreased by training and L-arginine. In this regards, liver MDA and CAT respectively increased and decreased in MI-groups, but aerobic training and L-arginine increased liver glutathione per-oxidase (GPx) and decreased liver MDA. CONCLUSION: These results demonstrated that kidney and liver function impaired 14 weeks after MI and aerobic training and L-arginine supplementation synergistically ameliorated kidneys and liver injury in myocardial infarction rats through oxidative stress reduction.

Prediction of Maximal Oxygen Uptake by Six-Minute Walk Test and Body Mass Index in Healthy Boys.

OBJECTIVE: To develop an equation to predict maximal oxygen uptake (VO2max) based on the 6-minute walk test (6MWT) and body composition in healthy boys. STUDY DESIGN: Direct VO2max, 6-minute walk distance, and anthropometric characteristics were measured in 349 healthy boys (12.49 ± 2.72 years). Multiple regression analysis was used to generate VO2max prediction equations. Cross-validation of the VO2max prediction equations was assessed with predicted residual sum of squares statistics. Pearson correlation was used to assess the correlation between measured and predicted VO2max. RESULTS: Objectively measured VO2max had a significant correlation with demographic and 6MWT characteristics (R = 0.11-0.723, P < .01). Multiple regression analysis revealed the following VO2max prediction equation: VO2max (mL/kg/min) = 12.701 + (0.06 × 6-minute walk distance m) - (0.732 × body mass indexkg/m2) (R2 = 0.79, standard error of the estimate [SEE] = 2.91 mL/kg/min, %SEE = 6.9%). There was strong correlation between measured and predicted VO2max (r = 0.875, P < .001). Cross-validation revealed minimal shrinkage (R2p = 0.78 and predicted residual sum of squares SEE = 2.99 mL/kg/min). CONCLUSIONS: This study provides a relatively accurate and convenient VO2max prediction equation based on the 6MWT and body mass index in healthy boys. This model can be used for evaluation of cardiorespiratory fitness of boys in different settings.

Effect of Educational Program, Based on PRECEDE and Trans-Theoretical Models, on Preventing Decline in Regular Physical Activity and Improving it among Students.

BACKGROUND: Adolescents especially middle school girls do not follow 60 min of regular physical activity (RPA), recommended by WHO, and endure physical activity decline. Using theory-based interventional program, considering the age of decline in RPA, seems to be effective. The aim of this study was to determine the effects of educational program, based on PRECEDE and Trans-Theoretical models, on preventing decline in RPA and improving it among 7th grade girl students. STUDY DESIGN: Randomized controlled trial. METHODS: This study was conducted on 7th grade girl students in Hamadan, west of Iran from 2015-16. Participants were divided into intervention (N=179) and control (N=165) groups by random assignment. Physical activity questionnaire for adolescents and the model-based questionnaire were used before and after intervention. Intervention included two months education and six months follow up. The effects of intervention were determined by statistical test and analysis of covariance using SPSS version 16. RESULTS: The higher change in the mean scores was observed in self-efficacy (0.86), counter condition (0.66) and helping relationship (0.57) in the intervention group (P≤0.001). In addition, a significant difference (P ≤0.001) was observed between the two groups 6 months after the intervention in all constructs of model. The mean score of doing physical activity in the intervention group increased from 2.50 to 3.17 that it was differed significantly from the control group (P≤0.001).  CONCLUSIONS: School based intervention using PRECEDE and Trans-Theoretical models might prevent girl students' RPA decline and improve their RPA.

Endurance training induces fiber type-specific revascularization in hindlimb skeletal muscles of rats with chronic heart failure.

OBJECTIVES: Previous studies showed that skeletal muscle microcirculation was reduced in chronic heart failure. The aim of this study was to investigate the effects of endurance training on capillary and arteriolar density of fast and slow twitch muscles in rats with chronic heart failure. MATERIALS AND METHODS: Four weeks after surgeries (left anterior descending (LAD) artery occlusion), chronic heart failure rats were divided into 3 groups: Sham (Sham, n=10); Sedentary (Sed, n=10); Exercise training (Ex, n=10). Ex group rats were subjected to endurance training in the form of treadmill running with moderate intensity for 10 weeks. RESULTS: Exercise training significantly increased capillary density and capillary to fiber ratio (P<0.05) in slow twitch muscle, but didn't change fast twitch muscle capillary density and capillary to fiber ratio. Furthermore, arteriolar density in fast twitch muscle increased remarkably (P<0.05) in response to training, but slow twitch muscle arteriolar density did not change in response to exercise in chronic heart failure rats. HIF-1 increased (P<0.01) but VEGF and FGF-2 mRNA did not change in slow twitch muscle after training. In fast twitch muscle, HIF-1 mRNA increased (P<0.05), and VEGF and angiostatin decreased (P<0.01) significantly after training. CONCLUSION: Endurance training ameliorates fast and slow twitch muscle revascularization non-uniformly in chronic heart failure rats by increasing capillary density in slow twitch muscle and arteriolar density in fast twitch muscle. The difference in revascularization at slow and fast twitch muscles may be induced by the difference in angiogenic and angiostatic gene expression response to endurance training.

The impact of rapid weight loss (4%) on leptin, adiponectin, and insulin resistance in elite adult free style wrestlers.

BACKGROUND: The effect of rapid weight loss program on adipocytokines is not yet clear. Therefore the aim of the present study was the effect of rapid weight loss (4%) on leptin, adiponectin, and insulin resistance in elite free style wrestlers. METHODS: For this purpose, fifteen young freestyle wrestlers (weight 67.6±0.8, BMI 22.5±0.21 kg/m², body fat percent 6.12±0.18, waist to hip circumference ratio 0.82±0.08) in two weight categories (60 and 66 kg) were randomly selected. Caloric intake (mean 7 days measured by Food analyzer software) measured at 1 week before weight loss program by standard methods. Wrestlers performed a week rapid weight loss (average of 4% of body weight loss) protocol by caloric and water restriction by 60% (600-700 kcal per day), under the supervision of their coach. Anthropometric characteristics, leptin, adiponectin and insulin resistance were measured before and 12 and 36 hours after rapid weight loss program. RESULTS: Rapid weight loss program with 4% of weight loss had a significantly reduced impact on anthropometric factors; leptin level, insulin resistance, and increased beta cell function, while the changes of adiponectin were not significant after rapid weight loss. CONCLUSIONS: Findings of this study shows that rapid weight loss program significantly decreased leptin, L/A ratio and HOMA-IR, without significant changes on adiponectin levels. These changes may have harmful physiological effects on wrestlers' bodies but they can be useful to regulate of fatty acid, glucose metabolism, and insulin resistance.

Effect of Exercise Training and L-arginine on Oxidative Stress and Left Ventricular Function in the Post-ischemic Failing Rat Heart.

The aim of the present study was to evaluate the effect of exercise training (ET) and L-arginine on oxidative stress and ventricular function in rat with myocardial infarction (MI). Four weeks after the surgical procedures, 40 Wistar male rats were randomized to the following groups: MI-sedentary (Sed); MI-exercise (Ex); MI-sedentary + L-arginine (Sed + LA); and MI-exercise + L-arginine (Ex + LA); the rats were subjected to aerobic training in the form of treadmill running. Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. Before and after the training program, all subjects underwent resting echocardiography. Catalase (CAT) glutathione peroxidase (GPx), malondialdehyde (MDA) and myeloperoxidase (MPO) were measured. Cardiac output, stroke volume and fractional shortening in Ex and Ex + LA groups significantly increased in comparison with the Sed group. Cardiac systolic function indices in Ex + LA group were significantly greater than Ex group. Also, GPx activity and MDA, respectively, increased and decreased in response to ET, but no change was observed in MPO and CAT. These results suggest that ET increased LV function by decreasing oxidative stress and increasing antioxidant defense system in rats with MI. In addition in response to training, L-arginine appears to have additive effect on cardiac function, but have no effect on oxidative stress indices.

Beneficial Effects of Endurance Exercise with Rosmarinus officinalis Labiatae Leaves Extract on Blood Antioxidant Enzyme Activities and Lipid Peroxidation in Streptozotocin-Induced Diabetic Rats.

OBJECTIVE: The aim of this study was to analyze the effects of endurance exercise training accompanying Rosmarinus officinalis Labiatae (rosemary) leaves extract on lipid peroxidation and antioxidative systems in the blood of rats with streptozotocin-induced diabetes. METHOD: To this end, 50 male Wistar rats were randomly divided into 5 groups: the sedentary control, sedentary diabetic, trained diabetic, diabetic plus rosemary extract treatment and trained diabetic plus rosemary extract treatment groups. Animals in the trained groups were exercised on a treadmill 4 days a week for 8 weeks. After 8 weeks, blood samples were taken from all animals and analyzed for erythrocyte superoxide dismutase, glutathione peroxidase, catalase activities and malondialdehyde levels. RESULTS: Compared to the sedentary control group, erythrocyte superoxide dismutase, glutathione peroxidase, and catalase activities in the sedentary diabetic group were significantly lower (p<0.001, p<0.001, p<0.001, respectively), whereas erythrocyte malondialdehyde levels in the sedentary diabetic group were significantly higher (p<0.001) than those in the sedentary control group. Due to endurance exercise with rosemary leaf extract, the antioxidant enzyme activities and the malondialdehyde levels in the trained diabetic plus rosemary extract treatment group reached the normal levels of those in the healthy group. CONCLUSIONS: These data demonstrated that the levels of lipid peroxidation in the erythrocyte of diabetic rats were high, whereas there was a decrease in the basal antioxidant enzyme activities. However, rosemary extract with endurance exercise may attenuate oxidative stress by enhancing antioxidant enzyme activities and decreasing lipid peroxidation levels in experimental rats with diabetes.

Synergistic effects of nitric oxide and exercise on revascularisation in the infarcted ventricle in a murine model of myocardial infarction.

It has been shown that density of microvessels decreases in the left ventricular after myocardial infarction (MI). The change of angiogenic and angiostatic factors as the main factors in revascularisation after exercise training in area at risk is not determined yet in MI. Therefore, the aim of the present study was the effect of exercise training and L-arginine supplementation on area at risk angiogenesis in myocardial infarction rat. Four weeks after surgery (Left Anterior Descending Coronary artery Ligation), myocardial infarction rats were divided into 4 groups: Sedentary rats (Sed-MI); L-arginine supplementation (La-MI); Exercise training (Ex-MI) and Exercise + L-arginine (Ex+La). Exercise training (ET) lasted for 10 weeks at 17 m/min for 10-50 min day(-1). Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. After ET and L-arginine supplementation, ventricular function was evaluated and angiogenic and angiostatic indices were measured at ~1 mm from the edge of scar tissue (area at risk). Statistical analysis revealed that gene expression of VEGF as an angiogenic factor, angiostatin as an angiostatic factor and caspase-3 at area at risk decrease significantly in response to exercise training compared to the sedentary group. The capillary and arteriolar density in the Ex groups were significantly higher than those of the Sed groups. Compared to the Ex-MI group, the Ex+La group showed a markedly increase in capillary to fiber ratio. No significant differences were found in infarct size among the four groups, but cardiac function increased in response to exercise. Exercise training increases revascularization at area at risk by reduction of angiostatin. L-arginine supplementation causes additional effects on exercise-induced angiogenesis by preventing more reduction of VEGF gene expression in response to exercise. These improvements, in turn, increase left ventricular systolic function and decrease mortality in myocardial infarction rats.

The role of exercise training on lipoprotein profiles in adolescent males.

BACKGROUND: Major cardiovascular disorders are being recognized earlier in life. In this study we examined the effects of swimming and soccer training on male adolescent lipid-lipoprotein profiles relative to a maturity matched control group to determine the effects of these exercises on specific cardiovascular risk and anti-risk factors. METHODS: Forty five adolescent males (11.81 ± 1.38 yr) including swimmers (SW), soccer players (SO), and non-athlete, physically active individuals as controls (C), participated in this study. Training groups completed 12-wk exercise programs on three non-consecutive days per week. Plasma low-density lipoprotein (LDL), very low density lipoprotein (VLDL), high density lipoprotein (HDL), apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), total cholesterol (TC), and triglyceride (TG) levels were measured in control, pre-training, during-training, and post-training. RESULTS: In response to the 12-wk training period, the SO group demonstrated a decrease in the mean LDL level compared to the SW and C (SW: 0.15%; SO: -9.51%; C: 19.59%; p < 0.001) groups. There was an increase in both the SW and SO groups vs. the control in mean HDL (SW: 5.66%; SO: 3.07%; C: -7.21%; p < 0.05) and apoA-I (SW: 3.86%; SO: 5.48%; C: -1.01%; p < 0.05). ApoB was considerably lower in the training groups vs. control (SW: -9.52%; SO: -13.87%; C: 21.09%; p < 0.05). ApoA-I/apoB ratio was significantly higher in training groups vs. control (SW: 16.74%; SO: 23.71%; C: -17.35%; p < 0.001). There were no significant differences between groups for other factors. CONCLUSIONS: The favorable alterations in LDL, HDL, apoA-I, and apoB observed in the training groups suggest that both regular swimming or soccer exercise can potentially mitigate cardiovascular risk in adolescent males.

The influence of oral magnesium sulfate on skin microvasculature blood flow in diabetic rats.

Microvascular disease is a major feature of type1 diabetes and results from long-standing structural and functional changes especially in the skin microvasculature. Magnesium (Mg) deficiency has recently been proposed as a novel factor implicated in the pathogenesis of diabetes complications such as vascular disturbance, but its mechanism of action is not completely elucidated. The present study was designed to determine whether chronic magnesium sulfate administration could control streptozocin-induced diabetes and improve endothelium-dependent and endothelium-independent dilatation, and identify its probable mechanism in the skin microvasculature of diabetic rats. Fifty male Wistar rats (220 ± 10 g) were divided into two diabetic and one control groups. One subgroup of diabetic received magnesium sulfate (10 g/l) in their drinking water, while two other groups had only tap water. Laser Doppler flow meter with iontophoresis was used to measure the relative changes in skin blood flow. We used acetylcholine (Ach), sodium nitroprusside (SNP), and N (w)-nitro-L-arginine (LNNA; NO synthase inhibitor) with magnesium sulfate (0.1 M) in control and experimental animal by microsyringe pump microinjection. SNP- and Ach-induced cutaneous perfusion increased significantly by Mg treatment in the diabetic groups, and local microinjection of magnesium sulfate (0.1 M) increased cutaneous blood flow in all groups (p < 0.01). However, the administration of LNNA prior to magnesium sulfate attenuated (p < 0.05) but not abolished the increase in cutaneous blood flow in diabetic and normal rats. From the results of this study, it may be concluded that Mg could improve skin microvasculature of diabetic rats with potentiation of nitric oxide pathway.