Effect of Exercise Training on Some Anti-Inflammatory Adipokines, High Sensitivity C-Reactive Protein, and Clinical Outcomes in Sedentary Adults With Metabolic Syndrome

OBJECTIVE

This study aimed to investigate the effects of aerobic interval training and resistance training on anti-inflammatory adipokines, high sensitivity C-reactive protein, and clinical outcomes in sedentary men with metabolic syndrome.

METHODS

A total of 33 sedentary men with metabolic syndrome (age: 46.2 ± 4.6 years; body mass index: 35.4 ± 1.9 kg.m2) were randomly assigned to one of 3 groups: aerobic interval training (n = 12), resistance training (n = 10), or control (n = 11). Participants in the exercise groups completed a 12-week training program, 3 sessions per week, while those in the control group maintained their sedentary lifestyle. The levels of high sensitivity C-reactive protein (hs-CRP), omentin-1, adiponectin, lipid profiles, blood pressure, glucose metabolism, body composition, and peak oxygen uptake (VO2peak) were measured at baseline and after the intervention.

RESULTS

Both aerobic interval training and resistance training significantly improved the levels of omentin-1 and adiponectin, as well as reduced inflammation, as indicated by a decrease in hs-CRP levels. Exercise training also led to significant improvements in lipid profiles, blood pressure, glucose metabolism, and body composition. Specifically, the aerobic interval training group had significantly greater increases in high-density lipoprotein cholesterol and VO2peak, as well as greater reductions in low-density lipoprotein cholesterol, triglycerides, and total cholesterol compared to the resistance training group.

CONCLUSION

Exercise training, particularly aerobic interval training and resistance training, can be an effective non-pharmacological intervention for managing inflammation and improving cardiovascular health in metabolic syndrome patients.

One-year Aerobic Interval Training Improves Endothelial Dysfunction in Patients with Atrial Fibrillation: A Randomized Trial

Objective To evaluate the effects of one-year aerobic interval training on endothelial dysfunction in patients with atrial fibrillation. Methods Seventy-four patients with atrial fibrillation (53 men, 21 women; mean age 63±6 years old) were randomized into a 1-year continuous aerobic interval training (CT), 6-month detraining after 6 months of aerobic interval training (DT), or medical treatment only (MT) group. Aerobic interval training was performed 3 times a week for 1 year or 6 months, with an exercise intensity of 85-95% of the peak heart rate. The primary outcome was a change in biomarkers of endothelial dysfunction from baseline at six months or at the one-year follow-up. Results Six-month aerobic interval training reduced von Willebrand factor (CT: 103.7±30.7 IU/dL and DT: 106±31.2 IU/dL vs. MT: 145±47.7 IU/dL, p=0.044). Improvements were maintained with continuous aerobic interval training; however, the values increased again to the baseline levels upon detraining (CT: 84.3±39.1 IU/dL vs. DT: 122.2±27.5 IU/dL and MT: 135.9±50.4 IU/dL, p=0.002). Interleukin 1 beta levels decreased after 6 months of aerobic interval training (CT: 0.59±0.1 pg/mL and DT: 0.63±0.09 pg/mL vs. MT: 0.82±0.28 pg/mL, p=0.031), and the improvement was maintained with continuous aerobic interval training and even after detraining (CT: 0.58±0.08 pg/mL and DT: 0.62±0.09 pg/mL vs. MT: 0.86±0.28 pg/mL, p=0.015). Conclusion One-year aerobic interval training improves endothelial dysfunction in patients with atrial fibrillation and is primarily associated with the reduction in circulating thrombogenic and pro-inflammatory factors. A definitive way to sustain these improvements is the long-term continuation of aerobic training.

[KLF15/mTOR related proteins involved in effect of aerobic interval training on improving skeletal muscle lesions in rats with type 2 diabetes]

Objective: To investigate the effects of aerobic intermittent exercise on the expressions of KLF15/mTOR related proteins to improve skeletal muscle lesions in type 2 diabetes rats. Methods: The experimental model of type 2 diabetes rats was established by feeding high-fat diet for 4 weeks and intraperitoneal injection of streptozotocin (STZ). After modeling, rats were randomly divided into two groups: diabetes model group (DM), diabetes+exercise group (DE), and normal rats were set as control group (C), 10 rats in each group. Group DE was given 8-week aerobic intermittent treadmill exercise intervention, while group C was not given any intervention. At the end of the experiment, the expressions of KLF15, mTOR, p-mTOR, and cleared caspase-3 in gastrocnemius muscle were detected by Western blot. The histopathologic changes of gastrocnemius were observed under microscope; skeletal muscle cells apoptosis rates and muscle mass were examined respectively using HE staining and TUNEL fluorescence staining. At the same time, changes of blood glucose and serum insulin, and weight were examined in the end of the experiment. Results: ①Compared with group C, the wet weight of gastrocnemius muscle and body weight, ratio of wet gastrocnemius muscle and body weight in group DM were decreased(P＜0.05 or P＜0.01); compared with group DM, the wet weight of gastrocnemius muscle, ratio of wet gastrocnemius muscle and body weight in the group DE were increased significantly (P＜0.05). ②Compared with group C, the fasting blood glucose level of group DM was increased significantly (P＜0.01), while serum insulin level of the group DM was decreased significantly(P＜0.01);compared with group DM, the above indexes were opposite in the group DE with intervention(P＜0.05). ③Compared with group C, the morphology of skeletal muscle cells in group DM was abnormal, the number of muscle nuclei was increased, the transverse lines were blurred and disappeared, the sarcomere was broken, and some muscle fibers were dissolved. Compared with group DM, the abnormal cell morphology, segmental injury of sarcomere and dissolution of muscle fibers in group DE were improved. The sarcolemma was more complete and the arrangement of muscle nuclei was more orderly. ④Compared with group C, the expressions of KLF15 and cleaved caspase-3, cells apoptosis rates in group DM were increased significantly(P＜0.01), while p-mTOR/mTOR level was decreased(P＜0.01) ; compared with group DM, the above indexes were opposite in the group with intervention(P＜0.05 or P＜0.01). Conclusion: Aerobic intermittent exercise is beneficial to improve the skeletal muscle pathological changes in type 2 diabetes rats, which may be due to the effective regulation of KLF15/mTOR related protein expression and the reduction of apoptosis damage.

Amelioration of Ambient Particulate Matter (PM2.5)-Induced Lung Injury in Rats by Aerobic Exercise Training

Ambient particulate matter (PM_2.5), as an inflammation-inducing factor, increases the prevalence of lung injury. The aim of this study was to examine the protective effect and mechanism of aerobic exercise on PM_2.5 exposure-induced lung injury. Forty Wistar rats were randomly divided into four groups: sedentary+PM_2.5 exposure, exercise+PM_2.5 exposure, sedentary, and exercise groups. All rats in the exercise-related groups underwent 8-week aerobic interval treadmill training (5daysweek⁻¹, 1hday⁻¹). PM-exposed rats were exposed to ambient PM_2.5 (6h day⁻¹) for 3weeks after the 8-week exercise intervention. Then, ventilation function, histopathological changes, and inflammation responses of pulmonary tissue were examined. Results showed that PM_2.5 exposure induced lung injury as manifested by decreased pulmonary function, abnormal histopathological changes, and increased pro-inflammatory cytokine levels (tumor necrosis factor-α and Interleukin-1α). Aerobic exercise alleviated the airway obstruction, reduced respiratory muscle strength, bronchial mucosal exfoliation, ultrastructure damage, and inflammatory responses induced by PM_2.5 in exercise-related groups. The benefits of exercise were related with the downregulation of p38-mitogen-activated protein kinase (MAPK), and the subsequent inhibition of the pathways of the cyclooxygenase 2 (COX-2) product, prostaglandin E₂ (PGE₂). Thus, pre-exercise training may be an effective way to protect against PM_2.5-induced lung inflammatory injury in rats.

Aerobic interval training improves irisin and chemerin levels of both liver and visceral adipose tissues and circulating asprosin in rats with metabolic syndrome

The perturbation of adipokinetic hormones, such as irisin, chemerin, and asprosin has been reported to participate in pathological conditions (e.g., insulin resistance) and chronic inflammation. However, exercise training has been long established as an effective intervention for prevention and treatment of these chronic and metabolic diseases. This study was to examine the effects of aerobic continuous training (ACT) and aerobic interval training (AIT) on irisin and chemerin levels of liver tissue (LT) and visceral adipose tissue (VAT), circulating asprosin, and their relationships with cardiometabolic risk factors in rats with metabolic syndrome (MetS). Thirty-two male Wistar rats were randomly divided into four equal groups: normal control (N-Ctr), control (Ctr-MetS), ACT, and AIT. After familiarization, rats with exercise intervention performed either ACT or AIT five times a week over eight weeks. The level of irisin in both ACT and AIT groups was higher than the Ctr-MetS group in LT and VAT, with a greater improvement of LT level observed in AIT vs. ACT groups. Furthermore, the level of chemerin in LT and VAT was lower in both ACT and AIT groups than the Ctr-MetS group, whereas only AIT group exhibited a reduction of serum asprosin when compared to ACT and Ctr-MetS, along with the improvements of cardiometabolic markers, such as HOMA-IR and lipid profile. These findings may support the efficiency and effectiveness of AIT intervention in the modulation of these novel metabolic hormones and cardiometabolic risk factors for reduced risk of metabolic syndrome.

[Effects of aerobic interval training on myocardial oxidative stress and inflammation in rats with myocardial infarction and its mechanism]

Objective: The present study was to determine the effects of aerobic interval training (AIT) on the expressions of SIRT1, Nox4 and inflammatory factor in the heart of rats with myocardial infarction (MI). Methods: Male Sprague Dawley rats were randomly divided into sham-operated group (C), sedentary MI group (MI) and MI with AIT group (ME) (n=10). The MI model was established by ligation the left anterior descending coronary artery. Rats in C groups were subjected to the same surgery, but only threaded and not ligated. After surgery 1 week, rats in ME groups took adaptability training for 1 week, and then subjected to 4 weeks treadmill exercise training. After training, the hearts were collected for histological observation. The level of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in heart was assessed by ultraviolet spectrophotometry. The activity of lactate dehydrogenase (LDH) was determined by enzyme linked immunosorbent assay. The expression of sirtuin1 (SIRT1) mRNA was examined by real-time quantitative polymerase chain reaction (RT-qPCR). The protein expressions of SIRT1, NADPH oxidase 4 (Nox4), tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) were detected by Western blotting. The levels of reactive oxygen species (ROS) were detected by dihydroethidium (DHE) staining. Results: Compared with the C group, the expression level of cardiac Nox4 protein was increased (P＜0.01), the level of MDA, activity of LDH and the level of ROS were increased significantly (P＜0.01), and the expressions of TNF-α and IL-1β protein were augmented in the heart of rats with MI (P＜0.01). However, the expressions of SIRT1 mRNA and protein and the activity of SOD were obviously decreased in MI group (P＜0.01). Furthermore, compared with the MI group, AIT increased the expressions of SIRT1 mRNA and protein and the activity of SOD in the heart of ME group (P＜0.01); Meanwhile, the expressions of cardiac Nox4, MDA level, LDH activity and ROS level were diminished in ME group (P＜0.01) as well as the decreased expressions of TNF-α and IL-1β protein (P＜0.01). SIRT1 expression was negatively related to the expressions of NOX4 and ROS. Conclusion: AIT obviously inhibited myocardial oxidative stress and inflammatory reaction, improved cardiac function in rats with MI, and the mechanism was closely related to the activation of SIRT1-Nox4-ROS signaling pathway.

Sex differences in physical and mental health following high-intensity interval training in adults with cardiovascular disease who completed cardiac rehabilitation

This pre-post study examined sex-differences in peak aerobic power (V̇O2peak) and physical- and mental-health outcomes in adults with cardiovascular disease who completed high-intensity interval training (HIIT)-based cardiac rehabilitation. HIIT consisted of 25 minutes of alternating higher- (4×4 minutes 85-95% heart rate peak (HRpeak)) and lower- (3×3 minutes 60-70% HRpeak) intensity intervals twice weekly for 10 weeks. V̇O2peak estimated from a graded exercise test using the American College of Sports Medicine equation, body mass index (BMI), waist circumference, blood pressure, blood biomarkers and anxiety and depression were assessed at baseline and follow-up. Linear mixed-effects models for repeated measures were performed to examine differences over time between sexes. Of 140 participants (mean ± standard deviation: 58 ± 9 years), 40 were female. Improvements in V̇O2peak did not differ between sexes (interaction: p = 0.273, females: 28.4 ± 6.4 to 30.9 ± 7.6; males: 34.3 ± 6.3 to 37.4 ± 6.0 mL/kg/min). None of the time by sex interactions were significant. Significant main effects of time showed reductions in waist circumference, triglycerides, low-density lipoprotein (LDL), total cholesterol (TC)/high-density lipoprotein (HDL) and anxiety, and increases in V̇O2peak and HDL from baseline to follow-up. Significant main effects of sex revealed smaller V̇O2peak, BMI and waist circumference, and higher LDL, TC and HDL in females than males. HIIT led to similar improvements in estimated V̇O2peak (females: 8.8%, males: 9.0%) and additional health outcomes between sexes. Novelty: HIIT-based cardiac rehabilitation led to similar improvements in estimated V̇O2peak and other physical and mental health outcomes between sexes. The number of sessions attended was high (>70%) and did not differ by sex. Both sexes showed good compliance with the exercise protocol (HR target).

Acute effect of HIIT on testosterone and cortisol levels in healthy individuals: A systematic review and meta-analysis

To determine the acute effect of a single high-intensity interval training (HIIT) session on testosterone and cortisol levels in healthy individuals, a systematic search of studies was conducted in MEDLINE and Web of Science databases from inception to February 2020. Meta-analyses were performed to establish the acute effect of HIIT on testosterone and cortisol levels immediately after a single HIIT session; after 30 min and 60 min (primary outcomes); and after 120 min, 180 min, and 24 h (secondary outcomes, only for pre-post intervention groups). Potential effect-size modifiers were assessed by meta-regression analyses and analyses of variance. Study quality was assessed using the Cochrane's risk of bias tool and the Physiotherapy Evidence Database scale. The meta-analyses of 10 controlled studies (213 participants) and 50 pre-post intervention groups (677 participants) revealed a significant increase in testosterone immediately after a single HIIT session (d = 0.92 and 0.52, respectively), which disappeared after 30 min (d = 0.18 and -0.04), and returned to baseline values after 60 min (d = -0.37 and -0.16). Significant increases of cortisol were found immediately after (d = 2.17 and 0.64), after 30 min (d = 1.62 and 0.67) and 60 min (d = 1.32 and 0.27). Testosterone and cortisol levels decreased significantly after 120 min (d = -0.48 and -0.95, respectively) and 180 min (d = -0.29 and -1.08), and returned to baseline values after 24 h (d = 0.14 and -0.02). HIIT components and participant's characteristics seem to moderate the effect sizes. In conclusion, testosterone and cortisol increase immediately after a single HIIT session, then drop below baseline levels, and finally return to baseline values after 24 h. This meta-analysis provides a better understanding of the acute endocrine response to a single HIIT session, which would certainly be valuable for both clinicians and coaches in the prescription of exercise programs to improve health and performance. Testosterone and cortisol may be used as sensitive biomarkers to monitor the anabolic and catabolic response to HIIT.

Efficacy of Vitamin D Supplementation in Addition to Aerobic Exercise Training in Obese Women with Perceived Myalgia: A Single-Blinded Randomized Controlled Clinical Trial

Obese women were more susceptible to myalgia because of their significantly lower vitamin D concentrations; the present study investigated the efficacy of vitamin D in addition to an aerobic interval training in the management of obese women with myalgia. Forty-five obese women with vitamin D deficiency and myalgia (30 to 40 years old) were assigned randomly into three equal groups. Group A received an aerobic interval training with vitamin D supplementation, Group B received vitamin D supplementation only, and Group C received aerobic interval training only; participants in all groups were on calorie deficient diets. The study outcomes were the Visual Analog Scale (VAS) for Pain Evaluation, serum vitamin D level, and Cooper 12-Minute Walk Test for Functional Capacity Evaluation, while the Short-Form Health Survey (SF) was used for assessment of quality of life. We detected a significant improvement in pain intensity level, serum vitamin D level, and quality of life in all groups with significant difference between Group A and groups B and C. We also detected a significant improvement in functional capacity in groups A and C, with no significant change in Group B. Aerobic interval training with vitamin D supplementation was more effective for the management of obese women with perceived myalgia.

Capturing the perspectives of women with coronary artery disease regarding interval training or continuous exercise in cardiac rehabilitation

Background: Motivators and barriers to exercise participation in women with coronary artery disease remain poorly understood. With evidence suggesting that women with coronary artery disease are less likely to adhere to exercise during cardiac rehabilitation and are more likely to drop out, it is important to understand these factors in order to optimize cardiac rehabilitation programs for women.Methods: We contribute to the discussion by presenting findings from a qualitative study using two focus groups with nine women with coronary artery disease sharing their experiences with attending cardiac rehabilitation and exercising in this setting, in addition to their perceived motivators and barriers to performing aerobic interval training. Focus group transcripts were analysed using a deductive thematic approach with Bandura's Social Cognitive Theory as the guiding conceptual framework.Results: Four themes were identified regarding the attitudes and experiences of attending and exercising at cardiac rehabilitation, while five themes capturing the motivators and barriers for these women to perform aerobic interval training were identified for the first time. These novel themes encompassed the daunting nature of it, the physical discomfort associated with it, and conversely, the potential sense of enjoyment and accomplishment that it could bring.Conclusion: This study demonstrates the complexity of implementation of aerobic interval training into clinical practice, and suggests that further research is warranted to explore this domain.IMPLICATIONS FOR REHABILITATIONDespite challenges in feasibility of conducting a randomised controlled trial in female patients with coronary artery disease examining the effects of aerobic interval training versus moderate-intensity continuous exercise on aerobic exercise capacity, there was a significant per protocol treatment effect of 0.95 ml·kg^-1·min^-1 in favour of aerobic interval training.The cardiac rehabilitation environment provides key facilitators and perceived benefits for exercising and attending cardiac rehabilitation for women, and thus emphasises the need for improving referral and enrolment processes specifically for women into cardiac rehabilitation programs.Aerobic interval training may elicit feelings of fear and physical discomfort, or may be precluded by comorbid conditions, therefore, judicious consideration must be taken in examining the suitability of implementation into clinical practice for each female patient.

Effects of interval training on inflammatory biomarkers in patients with ischemic heart failure

Objectives. Exercise training has been proposed to have anti-inflammatory effects. We examined whether aerobic interval training (AIT) can attenuate the inflammatory response in ischemic heart failure (HF) as measured by serum biomarkers representing a broad spectrum of activated inflammatory pathways. Design. We conducted a controlled prospective trial recruiting 30 patients (19 in the AIT group and 11 in the control group) with ischemic HF and an implantable cardioverter defibrillator (ICD). This study is a sub study of the previously reported "Aerobic interval training in patients with heart failure and an ICD" (Eur J Prev Cardiol. 22 March 2015; 22:296-303). Patients in the AIT group exercised for 12-weeks completing a total of 36 AIT sessions. We analyzed serum levels of C-reactive protein, pentraxin-3, osteoprotegerin, brain natriuretic peptide, neopterin, and soluble tumor necrois factor type 1 and 2, all known to predict an adverse outcome in HF, at baseline and following the 12-week AIT intervention. Results. The AIT group significantly increased peak oxygen uptake and improved endothelial function compared to the sedentary control group. No statistically significant changes in serum levels of the biomarkers were detected from baseline following the AIT intervention and, there were no significant differences in changes of these mediators between the AIT and the control group. Conclusions. A 12-week AIT intervention, although improving exercise capacity and endothelial function, did not attenuate serum inflammatory biomarkers in stable ischemic HF patients with an ICD on optimal medical therapy.

Eight Weeks of Aerobic Interval Training Improves Psychomotor Function in Patients with Parkinson's Disease-Randomized Controlled Trial

Background: This study examined the generalized effects of cycle ergometer aerobic interval training (AIT) on psychomotor behaviors in individuals with Parkinson’s disease (PD), including bimanual motor control, cognitive function, and neurological motor and non-motor parkinsonian signs. Methods: Twenty mild to moderate PD patients were randomly allocated to the following groups: (1) trained group (PD-TR, n = 10), which besides receiving usual care, underwent an 8-week moderate intensity AIT program; or (2) control group (PD-CO, n = 10) which received usual care, including participation in conventional physical therapy. Both groups were tested before and after the 8-week AIT program period with the following assessments: (1) laboratory analyses of bimanual motor control, (2) psychological evaluation of cognitive function, and (3) an evaluation of neurological parkinsonian signs. Results: The PD-TR group exhibited improved (1) bimanual motor control, reflected by a decreased time (p = 0.013) and increased rate of grip force development (p = 0.013) in the manipulating hand and a decreased time delay between grip force initiation in the manipulating and stabilizing hand (p = 0.020); (2) executive function, reflected by decreased performance time in part II of the Stroop Test (p = 0.007); and (3) neurological parkinsonian signs, reflected by an amelioration of upper-extremity bradykinesia (p = 0.015) and improvement in daily life manual functions (p = 0.004), mood, and intellectual function (p = 0.005). Conclusions: Following an 8-week moderate intensity AIT program, patients with PD exhibited improved psychomotor behaviors, reflected by bimanual motor control, executive function, and neurological parkinsonian signs.

Aerobic interval exercise improves renal functionality and affects mineral metabolism in obese Zucker rats

Obesity, metabolic syndrome, and renal injury are considered risk factors for type 2 diabetes, as well as kidney disease. Functional and structural changes in the kidney as consequence of obesity and metabolic syndrome may lead to impaired mineral metabolism in what is known as chronic kidney disease-mineral and bone disorder. Lifestyle interventions such as physical activity are good strategies to manage these pathologies and therefore, prevent the loss of kidney functionality and related complications in mineral metabolism. In this study, we have used 40 male Zucker rats that were randomly allocated into four different experimental groups, two of them (an obese and a lean one) performed an aerobic interval training protocol, and the other two groups were sedentary. At the end of the experimental period (8 wk), urine, plasma, and femur were collected for biochemical and mineral composition analysis, whereas the kidney was processed for histological studies. The obese rats exhibited albuminuria, glomerulosclerosis, and hypertrophy in glomeruli and renal tubule in some areas, together with alterations in mineral content of plasma but not of femur. The training protocol prevented the generation of albuminuria and glomerulosclerosis, showing a significant action on plasma and bone mineral levels. Therefore, the specific training protocol used in this study was able to prevent the development of diabetic nephropathy and affected the metabolism of certain minerals.

[Effect of aerobic interval training on the expression of renal CD40 in a rat model with myocardial infarction and its mechanism]

OBJECTIVE

To study the effects of aerobic interval training (AIT) on renal cluster of differentiation 40 (CD40) expression in rats with myocardial infarction (MI) and its possible mechanism.

METHODS

Thirty-six rats were randomly divided into three groups (n=12):Sham, MI and MI with AIT (ME) groups. The MI model was established by ligation of the left anterior descending coronary artery. Treadmill training was performed five times a week for 8 weeks (AIT:60 min/day with 10 min of warm-up at 10 m/min and 50 min of exercise at 25 m/min 7 min interspersed with 3 min at 15 m/min). After training, cardiaorenal function and renal tissue remodeling were evaluated. The changes of CD40, high-sensitivity C reactive protein(hs-CRP), TNF-α, IL-6, p-NF-κBp65, blood urea nitrogen (BUN) and serum creatinine (sCr) were determined.

RESULTS

Compared with the sham group, MI significantly increased left ventricular end-diastolic pressure (LVEDP) and decreased left ventricular systolic pressure (LVSP) and left indoor pressure change rate peak (dp/dtmax) in the MI group, concomitant with the increase in renal collagen volume fraction (CVF), which was reversed by AIT in the ME group. Moreover, compared with the sham group, CD40 was largely dispersed within the cytoplasm of renal tubule cells in the MI group. Meanwhile, the expressions of renal CD40 mRNA and protein, the levels of serum and renal hs-CRP, TNF-α and IL-6, the phosphorylation of NF-κBp65 (p-NF-κBp65) and the levels of sCr and BUN were obviously increased in the MI group. Compared with the MI group, AIT decreased the expressions of renal CD40 mRNA and protein, the levels of serum and renal hs-CRP, TNF-α and IL-6 and the expression of p-NF-κBp65, as well as decreased the levels of sCr and BUN in the ME group.

CONCLUSIONS

AIT reduces the expressions of renal CD40 protein and mRNA, inhibits NF-κB signaling pathway, and then decreases the levels of inflammatory factors thereby improve the renal dysfunction after MI.

Aerobic Interval Training and Cardiometabolic Health in Patients with Type 2 Diabetes: A Meta-Analysis

Vigorous to maximal aerobic interval training (INT) has received remarkable interest in improving cardiometabolic outcomes for type 2 diabetes patients recently, yet with inconsistent findings. This meta-analysis was aimed to quantify its effectiveness in type 2 diabetes. Randomized controlled trials (RCTs) were identified by searches of 3 databases to October 2017, which evaluated the effects of INT with a minimal training duration of 8 weeks vs. moderate-intensity continuous training (MICT) or non-exercise training (NET) among type 2 diabetes patients on outcomes including cardiorespiratory fitness, glycemic control, body composition, blood pressure, and lipid profiles. Weighted mean differences with 95% confidence intervals (CIs) were calculated with the random-effects model. Nine datasets from 7 RCTs with 189 patients were included. Compared with MICT, INT improved maximal oxygen consumption (VO_2max) by 2.60 ml/kg/min (95% CI: 1.32 to 3.88 ml/kg/min, P <0.001) and decreased hemoglobin A1c (HbA1c) by 0.26% (95% CI: −0.46% to −0.07%, P = 0.008). These outcomes for INT were also significant vs. energy expenditure-matched MICT, with VO_2max increased by 2.18 ml/kg/min (P = 0.04) and HbA1c decreased by 0.28% (P = 0.01). Yet their magnitudes of changes were larger compared with NET, with VO_2max increased by 6.38 ml/kg/min (P <0.001) and HbA1c reduced by 0.83% (P = 0.004). Systolic blood pressure could be lowered by INT compared with energy expenditure-matched MICT or NET (both P <0.05), but other cardiometabolic markers and body composition were not significantly altered in general. In conclusion, despite a limited number of studies, INT improves cardiometabolic health especially for VO_2max and HbA1c among patients with type 2 diabetes, and might be considered an alternative to MICT. Yet the optimal training protocols still require to be established.

The Combined Intervention with Germinated Vigna radiata and Aerobic Interval Training Protocol Is an Effective Strategy for the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD) and Other Alterations Related to the Metabolic Syndrome in Zucker Rats

Metabolic syndrome (MetS) is a group of related metabolic alterations that increase the risk of developing non-alcoholic fatty liver disease (NAFLD). Several lifestyle interventions based on dietary treatment with functional ingredients and physical activity are being studied as alternative or reinforcement treatments to the pharmacological ones actually in use. In the present experiment, the combined treatment with mung bean (Vigna radiata), a widely used legume with promising nutritional and health benefits that was included in the experimental diet as raw or 4 day-germinated seed flour, and aerobic interval training protocol (65–85% VO₂ max) has been tested in lean and obese Zucker rats following a 2 × 2 × 2 (2 phenotypes, 2 dietary interventions, 2 lifestyles) factorial ANOVA (Analysis of Variance) statistical analysis. Germination of V. radiata over a period of four days originated a significant protein hydrolysis leading to the appearance of low molecular weight peptides. The combination of 4 day-germinated V. radiata and aerobic interval training was more efficient compared to raw V. radiata at improving the aerobic capacity and physical performance, hepatic histology and functionality, and plasma lipid parameters as well as reverting the insulin resistance characteristic of the obese Zucker rat model. In conclusion, the joint intervention with legume sprouts and aerobic interval training protocol is an efficient treatment to improve the alterations of glucose and lipid metabolism as well as hepatic histology and functionality related to the development of NAFLD and the MetS.

Aerobic interval exercise improves parameters of nonalcoholic fatty liver disease (NAFLD) and other alterations of metabolic syndrome in obese Zucker rats

Metabolic syndrome (MS) is a group of metabolic alterations that increase the susceptibility to cardiovascular disease and type 2 diabetes. Nonalcoholic fatty liver disease has been described as the liver manifestation of MS. We aimed to test the beneficial effects of an aerobic interval training (AIT) protocol on different biochemical, microscopic, and functional liver alterations related to the MS in the experimental model of obese Zucker rat. Two groups of lean and obese animals (6 weeks old) followed a protocol of AIT (4 min at 65%-80% of maximal oxygen uptake, followed by 3 min at 50%-65% of maximal oxygen uptake for 45-60 min, 5 days/week, 8 weeks of experimental period), whereas 2 control groups remained sedentary. Obese rats had higher food intake and body weight (P < 0.0001) and suffered significant alterations in plasma lipid profile, area under the curve after oral glucose overload (P < 0.0001), liver histology and functionality, and antioxidant status. The AIT protocol reduced the severity of alterations related to glucose and lipid metabolism and increased the liver protein expression of PPARγ, as well as the gene expression of glutathione peroxidase 4 (P < 0.001). The training protocol also showed significant effects on the activity of hepatic antioxidant enzymes, although this action was greatly influenced by rat phenotype. The present data suggest that AIT protocol is a feasible strategy to improve some of the plasma and liver alterations featured by the MS.

Aerobic interval training protects against myocardial infarction-induced oxidative injury by enhancing antioxidase system and mitochondrial biosynthesis

1. Aerobic interval training (AIT) exerts beneficial effects on cardiovascular disease. However, its cardioprotective mechanisms are not fully understood. The aim of the present study was to evaluate AIT-mediated anti-oxidation by focusing on anti-oxidase and mitochondrial biogenesis in rats after myocardial infarction (MI). 2. Sprague-Dawley rats were divided into three groups: (i) a sham-operated control (CON); (ii) an MI group; and (iii) an MI + AIT group. Myocardial microstructure and function, markers of oxidative stress, mitochondrial anti-oxidase, Phase II enzymes and mitochondrial biogenesis were assessed. In addition, levels of nuclear factor-erythroid 2-related factor (Nrf2) and phosphorylated (p-) AMP-activated protein kinase (AMPK) were determined. The anti-oxidative gene sirtuin 3 (SIRT3) and the prosurvival phosphatidylinositol-3 kinase (PI3-K)-protein kinase B (Akt) signalling cascade were also evaluated. 3. Compared with CON, there was noticeable microstructure injury, cardiac dysfunction and oxidative damage in rats after MI. In addition, decreased mitochondrial anti-oxidase content, Phase II enzyme (except heme oxygenase-1) expression and mitochondrial biogenesis were observed in the post-MI rats as well as reduced protein levels of the regulators Nrf2 and p-AMPK and suppression of SIRT3 levels and PI3-K/Akt signalling. These detrimental modifications were considerably ameliorated by AIT, as evidenced by increases in anti-oxidase, mitochondrial biogenesis, Nrf2 and AMPK phosphorylation, as well as SIRT3 upregulation and PI3-K/Akt signalling activation. Moreover, PI3-K inhibitor-LY294002 (20 mg/kg) treatment partly attenuated AIT-elicited increases in Nrf2 levels and AMPK phosphorylation. 4. Based on these results, we conclude that AIT effectively alleviates MI-induced oxidative injury, which may be closely correlated with activation of the anti-oxidase system and mitochondrial biosynthesis. Increased SIRT3 expression and activation of PI3-K/Akt signalling may play key roles in AIT-mediated anti-oxidation. These results open up new avenues for exercise intervention therapies for MI patients.

High- and moderate-intensity aerobic exercise and excess post-exercise oxygen consumption in men with metabolic syndrome

Physical activity is central in prevention and treatment of metabolic syndrome. High-intensity aerobic exercise can induce larger energy expenditure per unit of time compared with moderate-intensity exercise. Furthermore, it may induce larger energy expenditure at post-exercise recovery. The aim of this study is to compare the excess post-exercise oxygen consumption (EPOC) in three different aerobic exercise sessions in men with metabolic syndrome. Seven men (age: 56.7 ± 10.8) with metabolic syndrome participated in this crossover study. The sessions consisted of one aerobic interval (1-AIT), four aerobic intervals (4-AIT), and 47-min continuous moderate exercise (CME) on separate days, with at least 48 h between each test day. Resting metabolic rate (RMR) was measured pre-exercise and used as baseline value. EPOC was measured until baseline metabolic rate was re-established. An increase in O2 uptake lasting for 70.4 ± 24.8 min (4-AIT), 35.9 ± 17.3 min (1-AIT), and 45.6 ± 17.3 min (CME) was observed. EPOC were 2.9 ± 1.7 L O2 (4-AIT), 1.3 ±  .1 L O2 (1-AIT), and 1.4 ± 1.1 L O2 (CME). There were significant differences (P < 0.001) between 4-AIT, CME, and 1-AIT. Total EPOC was highest after 4-AIT. These data suggest that exercise intensity has a significant positive effect on EPOC in men with metabolic syndrome.

Evidence for the contribution of muscle stem cells to nonhypertrophic skeletal muscle remodeling in humans

The purpose of this study was to explore the possible role of muscle stem cells, also referred to as satellite cells (SCs), in adaptation and remodeling following a nonhypertrophic stimulus in humans. Muscle biopsies were obtained from the vastus lateralis of previously untrained women (n=15; age: 27±8 yr, BMI: 29±6 kg/m(2)) before and after 6 wk of aerobic interval training. The fiber type-specific SC response to training was analyzed using immunofluorescent microscopy of muscle cross sections. Following training, the number of SCs associated with fibers expressing myosin heavy-chain type I and II isoforms (hybrid fibers) increased (pre: 0.062±0.035 SC/hybrid fiber; post: 0.38±0.063 SC/hybrid fiber; P<0.01). In addition, there was a greater number of MyoD(+)/Pax7(-) SCs, indicative of differentiating SCs, associated with hybrid fibers (0.18±0.096 MyoD(+)/Pax7(-) SC/hybrid fiber) compared to type I (0.015±0.00615 MyoD(+)/Pax7(-) SC/type I fiber) or II (0.012±0.00454 MyoD(+)/Pax7(-) SC/type II fiber) fibers (P<0.05). There was also a training-induced increase in the number of hybrid fibers containing centrally located nuclei (15.1%) compared to either type I (3.4%) or II fibers (3.6%) (P<0.01). These data are consistent with the hypothesis that SCs contribute to the remodeling of muscle fibers even in the absence of hypertrophy.