Aerobic Interval Training Group Research Articles

Treadmill exercise with nanoselenium supplementation affects the expression of Irisin/FNDC5 and semaphorin 3A in rats exposed to cigarette smoke extract.

In the current study, we investigated the impacts of 6 weeks of aerobic interval training (AIT) with selenium nanoparticles (SeNPs) on muscle, serum, and lung irisin (FNDC5) and Sema3A in rats exposed to cigarette smoke extract (CSE). To this end, 49 male Wistar rats (8 weeks old) were divided into seven groups: control, SeNPs (2.5mg/kg b.w by oral gavage, 3days/week, 6weeks), AIT (49min/day, 5days/week for 6weeks, interval), SeNPs + AIT, CSE (150 µL by IP injection, 1day/week for 6weeks), CSE + AIT, and CSE + SeNPs + AIT. The CSE group showed a significant reduction in irisin and Sema3A serum levels, as well as a decrease in FNDC5 and Sema3A gene expression in lung tissue (p < 0.05). A combined treatment (AIT with SeNPs) significantly increased the serum level and the expression of muscle and lung irisin (FNDC5) and Sema3A in CSE received groups (p < 0.05). There was a positive and significant correlation between muscle FNDC5 and lung FNDC5 in the CSE + SeNPs + AIT group (r = 0.92, p = 0.025). In addition, there was a positive and significant correlation between serum Sema3A and lung Sema3A of CSE + SeNPs + AIT group (r = 0.97, p = 0.004). Seemingly, performing aerobic exercises with the antioxidant and anti-inflammatory supplement nano-selenium in the model of lung damage (similar to COPD) can boost myokine irisin and Sema3A, especially in serum and lung tissue. These results displayed the paracrine/endocrine regulatory function of these myokines on other tissues. In other words, these interventions emphasized the creation of crosstalk between skeletal muscles and damaged lung, focusing on its recovery; however, further research is needed.

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

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. A total of 33 sedentary men with metabolic syndrome (age: 46.2 ± 4.6years; body mass index: 35.4 ± 1.9kg.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. 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. 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.

Blood Lactate AUC Is a Sensitive Test for Evaluating the Effect of Exercise Training on Functional Work Capacity in Patients with Chronic Heart Failure.

Purpose Exercise training is an essential treatment option for patients with chronic heart failure (CHF). However, it remains controversial, which surrogate measures of functional work capacity are most reliable. The purpose of this paper was to compare functional capacity work measured as capillary lactate concentrations area under the curve (AUC) with standard cardiopulmonary exercise testing (CPET) with VO2peak and the 6-minute walk test (6 MWT). Methods Twenty-three patients in New York Heart Association (NYHA) class II/III with left ventricular ejection fraction (LVEF) <35% were randomised to home-based recommendation of regular exercise (RRE) (controls), moderate continuous training (MCT) or aerobic interval training (AIT). The MCT and AIT groups underwent 12 weeks of supervised exercise training. Exercise testing was performed as standard CPET treadmill test with analysis of VO2peak, the 6 MWT and a novel 30-minute submaximal treadmill test with capillary lactate AUC. Results All patients had statistically significant improvements in VO2peak, 6 MWT and lactate AUC after 12 weeks of exercise training: 6 MWT (p =0.035), VO2peak (p =0.049) and lactate AUC (p =0.002). Lactate AUC (p =0.046) and 6MWT (p =0.035), but not VO2peak revealed difference between the exercise modalities regarding functional work capacity. Conclusion 6-MWT and lactate AUC, but not VO2peak, were able to reveal a statistically significant improvement in functional capacity between different exercise modalities.

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.

Comparative efficiency of continuous trainings and aerobic interval training in patients after myocardial infarction

Abstract Background The basis of cardiac rehabilitation programs (CRP) is aerobic physical training, which improves exercise capacity in patients with an acute myocardial infarction (MI) after primary angioplasty of the infarct-related vessel. However, which type - aerobic interval training (AIT) or aerobic continuous trainings (ACT) are most effective for improving peak oxygen uptake (VO2 max) remains unclear and controversial. Purpose To evaluate the effects of CRP, including AIT or ACT, on exercise capacity and lung function in patients with MI after primary angioplasty of the infarct-related vessel. Methods Seventy MI patients (58 men and 12 women, mean age – 59,2±8,0 years) were undergone the three-week CRP in the Ivanovo State Medical Academy Clinic. The CRP for all patients included: daily controlled physical training on the Bicycle Ergometer and Treadmill, group exercises in therapeutic gymnastics, dosed walking and walking on the stairs with an individually calculated pace. Depending on the mode of physical training all patients were randomized of five weekly sessions in to two groups, comparable in age and gender: AIT group (35 patients) and ACT group (35 patients). The ACT group was training at 50–60% of peak heart rate. The AIT group protocol consisted of ten 1-min intervals at 85–90% of maximal heart rate separated by ten 1-min active recovery periods of moderate intensity at 40–60% of the maximal heart rate. Changes in 6-min walk distance test (6MWT), peak oxygen uptake (VO2max), relative load power, total lung capacity (TLC) and forced expiratory volume in one second (FEV1) before and after CRP were investigated. Data are presented as a median (interquartile ratio [Q1; Q3]). Results After finishing CRP 6MWT distance increased in both groups, but was higher in AIT group 492 [460–510] m compared to the ACT group – 465 [424–510] m (p&amp;lt;0.05). Peak oxygen uptake increased more (p&amp;lt;0.05) after AIT: from 16.8 [15.3–19.8] to 20.7 [16.5–21.9] ml kg–1 min–1 (p&amp;lt;0.05), than after ACT – from 15.8 [14.7–18.6] to 16.1 [15.8–20.5] ml kg–1 min–1 (p&amp;gt;0.05). At the end of the CRP relative load power during cardiopulmonary exercise test was higher in AIT group compared to the ACT group: 1.5 [1.3–1.7] vs 1.2 [1.0–1.5] Wt/kg respectively (p&amp;lt;0.05). In the AIT group TLC increased significantly from 3.13 [2.63–4.05] to 4.14 [3.91–4.87] L (p&amp;lt;0.05) then in ACT group: from 3.19 [2.82–3.74] to 3.21 [3.03–3.57] L (p&amp;gt;0.05). FEV1 had no changes in both groups. Both programs reduced anxiety and depression, systolic and diastolic blood pressure and increased quality of life. Conclusion AIT as compared to ACT provided a more pronounced training effect on the cardiorespiratory system due to high-intensity loading phases. Therefore, AIT is more preferable in cardiac rehabilitation of patients with MI after primary angioplasty of the infarct-related vessel. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Ivanovo State Medical Academy

Semisupervised Physical Exercise and Lifestyle Counseling in Cardiometabolic Risk Management in Sedentary Adults: Controlled Randomized Trial (BELLUGAT).

The purpose of this study was to evaluate the feasibility and effectiveness of a high-intensity semisupervised exercise program alongside lifestyle counseling as an intervention for managing cardiometabolic risk in sedentary adults. A 40-week 3-arm randomized controlled clinical trial (16-wk intervention and 24-wk follow-up) was used. Seventy-five sedentary adults (34-55y) with at least 1 cardiometabolic risk factor were randomized into one of the following arms: (1)aerobic interval training (AIT) plus lifestyle counseling (n = 25), (2)low- to moderate-intensity continuous training plus lifestyle counseling (traditional continuous training, TCT) (n = 27), or (3)lifestyle counseling alone (COU) (n = 23). Metabolic syndrome severity scores, accelerometer-based physical activity, and self-reported dietary habits were assessed at baseline, after the intervention, and at follow-up. AIT was well accepted with high enjoyment scores. All groups showed similar improvements in metabolic syndrome severity scores (standardized effect size = 0.46) and dietary habits (standardized effect size = 0.30). Moderate to vigorous physical activity increased in all study groups, with the number of responders higher in AIT and TCT groups (50%) than in COU group (21%). Both AIT and TCT had a greater impact on sedentary behavior than COU (63.5% vs 30.4% responders). AIT appears to be a feasible and effective strategy in sedentary individuals with cardiometabolic risk factors. AIT could be included in intervention programs tackling unhealthy lifestyles.

Randomised controlled trial in women with coronary artery disease investigating the effects of aerobic interval training versus moderate intensity continuous exercise in cardiac rehabilitation: CAT versus MICE study

BackgroundThe primary aim of the present study was to investigate the effects of aerobic interval training (AIT) versus moderate intensity continuous exercise (MICE) on aerobic exercise capacity (V̇O2peak), in women...

Periodized Aerobic Interval Training Modifies Geometric Indices of Heart Rate Variability in Metabolic Syndrome.

Background: Metabolic syndrome (MetS) influences the autonomic modulation, increasing the risk of cardiovascular events, which demands the identification of effective treatments for this population. Considering this, the study has the objective of evaluating the effects of periodized aerobic interval training (AIT) on geometrical methods of heart rate variability (HRV) on individuals with MetS. Methods: 52 individuals with MetS were considered for analysis. They were divided into two groups: aerobic interval training group (AITG; n = 26) and control group (CG; n = 26). The AITG performed 16 weeks of periodized AIT. For HRV analysis, the heart rate was recorded beat-by-beat at the beginning and the end of the AIT program and geometrical methods were used for analysis. Results: significant increase was observed for triangular index (RRtri, −1.25 ± 0.58 vs. 1.41 ± 0.57), standard deviation of distances from diagonal to points (SD1, −0.13 ± 1.52 vs. 4.34 ± 1.49), and standard deviation of distances from points to lines (SD2, −2.14 ± 3.59 vs. 11.23 ± 3.52) on AITG compared to CG. Significant differences were not observed for triangular interpolation of normal heartbeats interval histogram (TINN, −4.05 ± 17.38 vs. 25.52 ± 17.03) and SD1/SD2 ratio (0.03 ± 0.02 vs. 0.00 ± 0.02). Qualitative analysis of the Poincaré plot identified increase on dispersion of both short and long-term intervals between successive heartbeats (RR interval) on AITG after the AIT program. Conclusion: geometric indices of HRV suggest an increase in cardiac autonomic modulation in individuals with MetS after 16 weeks of periodized AIT.

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.

An attempt to reverse cardiac lipotoxicity by aerobic interval training in a high-fat diet- and streptozotocin-induced type 2 diabetes rat model

BackgroundDiabetes mellitus (DM) is an important risk factor for cardiovascular disease. Aerobic interval training (AIT) has been recommended to patients as a non-pharmacological strategy to manage DM. However, little is known about whether AIT intervention at the onset of DM will reverse the process of diabetic cardiomyopathy (DCM). In this study, we sought to evaluate whether AIT can reverse the process of DCM and explore the underlying mechanisms.MethodsFifty Wistar rats were randomly divided into a control group (CON), DCM group (DCM) and AIT intervention group (AIT). A high-fat diet and streptozotocin (STZ) were used to induce diabetes in rats in the DCM group and AIT group. Rats in the AIT group were subjected to an 8-week AIT intervention. Fasting blood glucose (FBG), lipid profiles and insulin levels were measured. Haematoxylin and eosin (HE) staining and oil red O staining were used to identify cardiac morphology and lipid accumulation, respectively. Serum BNP levels and cardiac BNP mRNA expression were measured to ensure the safety of the AIT intervention. Free fatty acid (FFA) and diacylglycerol (DAG) concentrations were analysed by enzymatic methods. AMPK, p-AMPK, FOXO1, CD36 and PPARα gene and protein expression were detected by RT-PCR and Western blotting.ResultsAIT intervention significantly reduced rat serum cardiovascular disease risk factors in DCM rats (P < 0.05). The safety of AIT intervention was illustrated by reduced serum BNP levels and cardiac BNP mRNA expression (P < 0.05) after AIT intervention in DCM rats histological analysis and FFA and DAG concentrations revealed that AIT intervention reduced the accumulation of lipid droplets within cardiomyocytes and alleviated cardiac lipotoxicity (P < 0.05). CD36 and PPARα gene and protein expression were elevated in the DCM group, and these increases were reduced by AIT intervention (P < 0.01). The normalized myocardial lipotoxicity was due to increased expression of phosphorylated AMPK and reduced FOXO1 expression after AIT intervention.ConclusionAIT intervention may alleviate cardiac lipotoxicity and reverse the process of DCM through activation of the AMPK–FOXO1 pathway.

An Attempt To Reverse Diabetic Cardiomyopathy By Aerobic Interval Training In High-fat Diet And Streptozotocin Induced Type 2 Diabetes Rat Models

PURPOSE: Diabetes mellitus (DM) is an important risk factors of cardiovascular disease. Long-term hyperglycemia, hyperlipemia and insulin resistance may lead to diabetic cardiomyopathy (DCM). No rodent models fully captured the whole process of cardiac morphology and function changes during the course of DCM. Aerobic interval training (AIT) has been advised as a non-pharmacological strategy against DM patients. However, little is known whether impose AIT intervention at the onset of DM will reverse the process of DCM. In this study, we sought to evaluate the cardiac function during the development of DCM and explore whether AIT will reverse the process of DCM. METHODS: 60 Wistar male rats were randomly divided into control group (CON), DCM group (DCM) and AIT intervention group (AIT). Rats in DCM group and AIT group used high fat diet and STZ to induce diabetes models. Rats in AIT group were subjected to 8 weeks AIT intervention Fasting blood glucose (FBG), lipid profiles, insulin resistance (IR) and GLP-1 levels was measured. HE staining and echocardiography were used to identify cardiac morphology and function. α-MHC and β-MHC gene expression were detected by RT-PCR. GLP-1 and GLP-1R expression were detected by western blotting. RESULTS: Compared with CON, the heart function of DCM gradually changes from impaired diastolic function to impaired systolic function,with heart developed hypertrophy at onset and gradually cardiac walls became thinner with large LV volume. The FBG, TG and LDL-c levels in AIT was 16.8%, 45.6% and 74.7% lower than that in DCM (P<0.01). AIT increased HDL-c level up to 60% than DCM (P<0.01). AIT significantly decreased IR for 37.3% (P<0.01). Histological analysis and echocardiography results revealed that AIT prevent the thinners of cardiac wall and improve systolic and diastolic function. There is a 81% increase of α-MHC mRNA expression and a 67% decrease of β-MHC mRNA expression in AIT group than in DCM (P<0.01), which represented that AIT prevent the heart transformation to embryo type. AIT protect DCM heart through improving serum GLP-1 level (80%, P<0.05) , heart GLP-1 expression (144%, P<0.01) and GLP-1R expression (219%, P<0.01). CONCLUSIONS: AIT intervention may reverse the process of DCM by activating of GLP-1/GLP-1R signaling.

The Effectiveness of Progressive Aerobic Interval Training in Cardiac Rehabilitation.

Aerobic interval training (AIT) has recently emerged as a more effective strategy than moderate-intensity continuous exercise (MICE) for improving peak oxygen consumption (V˙O2peak) in coronary artery disease (CAD) patients. The primary purpose of this retrospective study was to describe the change in V˙O2peak, and cardiovascular (CV) risk profile characteristics (secondary outcomes) after progressive AIT practiced in the largest, outpatient cardiac rehabilitation (CR) program in North America compared with usual care CR involving MICE. Electronic database records were retrieved from consecutively enrolled patients with CAD who attended the Toronto Rehabilitation Institute, between January 1, 2005, and December 31, 2015. Patients were then separated into two, age and sex propensity score-matched groups: 772 patients were prescribed 26 wk of MICE (60%-80% of V˙O2peak, five times per week) as per usual care CR (56.0 ± 9.2 yr; 12% female/88% male; V˙O2peak: 20.8 ± 5.9 mL·kg·min), and 772 patients were prescribed 26 wk of progressive walk/jog intervals (15 min·mile walking pace, 12 min·mile jogging pace, five times per week) (55.9 ± 9.3 yr; 12% female/88% male; V˙O2peak: 24.8 ± 5.7 mL·kg ·min). Treatment effect analysis of AIT on V˙O2peak and CV risk profile characteristics was performed using multiple regression with baseline values as covariates. Treatment effect analysis revealed a 3.84-mL·kg·min superior improvement in V˙O2peak in the AIT group compared to usual care MICE group (P < 0.001). Furthermore, AIT significantly improved BMI, triglycerides, hip and abdominal girth, and depression score compared with MICE (P < 0.023 for all). Progressive AIT performed in a standard, outpatient CR program appears to be superior to usual care MICE for improving V˙O2peak, CV risk profile characteristics, and depression score in stable CAD patients. These findings may have important implications for exercise training guidelines in the rehabilitation setting, and in future studies.

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

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. 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. 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. 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.

Cycling Exercise Training Alleviates Hypoxia-Impaired Erythrocyte Rheology.

Physical exercise or hypoxic exposure influences hemorheology and acid-base homeostasis. Band 3 protein in erythrocytes modulates cells' rheological properties and anion transport ability. This study investigated how cycling aerobic interval training (AIT) and moderate continuous training (MCT) affect the rheological function and band 3 activity of erythrocytes under hypoxic exercise (HE) stress. Forty-five healthy sedentary men were randomized to engage in either AIT (3-min intervals at 40% and 80% of VO2max, n = 15) or MCT (sustained 60% of VO2max, n = 15) on a bicycle ergometer for 30 min · d(-1) (5 d · wk(-1) for 5 wk) or to a control group that did not perform any exercise (n = 15). Erythrocyte rheological responses to HE (100 W under 12% O2 for 30 min) were determined before and after various regimens. Acute HE increased the aggregation and osmotic fragility of erythrocytes, decreased the deformability of erythrocytes, and depressed erythrocyte band 3 activity, as indicated by lowered anion transport ability. Following 5 wk of intervention, the AIT group exhibited maximal work rate and VO2max higher than those in the MCT and control groups. Moreover, cycling AIT and MCT diminished the extent of erythrocytes' enhanced aggregation and osmotic fragility and reduced their deformability and band 3 activity caused by HE. Additionally, erythrocyte band 3 activity was directly related to erythrocyte deformability and inversely related to erythrocyte aggregation and osmotic fragility. Cycling AIT is superior to cycling MCT in enhancing aerobic capacity. Moreover, either cycling AIT or MCT effectively alleviates HE-evoked impairments of erythrocyte rheological characteristics and band 3 function.

Interval and continuous exercise enhances aerobic capacity and hemodynamic function in CHF rats.

OBJECTIVE: The aim of the present study was to compare the effects of continuous versus interval aerobic exercise training on hemodynamic parameters, cardiac remodeling, and maximal exercise capacity (MEC) in chronic heart failure (CHF) rats. METHOD: Twenty-four male Wistar rats were subjected to myocardial infarction (MI) surgery. Five weeks post MI, the animals were assigned to one of three groups: sedentary group (CHF-Sed, n=8), aerobic continuous training group (CHF-ACT, n=8), and aerobic interval training group (CHF-AIT, n=8). Treadmill training was performed five times a week for 8 weeks (ACT: 50 min/day at 15 m/min and AIT: 40 min/day with 8 min of warm-up at 10 m/min and exercise at 15 m/min 4×4 min interspersed with 4×4 min at 23 m/min). MEC was evaluated pre and post exercise program. RESULTS: Left ventricular end-diastolic pressure (LVEDP), left ventricular mass/body mass ratio (LVM:BM), and total collagen volume fraction were lower in the trained groups compared with the sedentary group, but no difference was found between the trained groups. Systolic ventricular pressure (SVP) and maximum positive derivative of LV pressure (+dP/dtmax) were higher in the trained groups, but CHF-ACT showed higher +dP/dtmax compared to CHF-AIT. Both training regimens were able to increase MEC. However, the aerobic interval training was superior for improving MEC. CONCLUSION: Aerobic training is an important intervention to improve cardiac function and remodeling and physical capacity in CHF rats. Interval training is a potential strategy to maximize the results, but exercise type and intensity are still topics to be explored.

Beneficial effects of combined exercise training on early recovery cardiopulmonary exercise testing indices in patients with chronic heart failure.

Exercise training induces several beneficial effects in patients with chronic heart failure (CHF). This study investigated the effects of high-intensity aerobic interval training (AIT) compared with combined AIT and strength training (COM) on early ventilatory and metabolic recovery pattern after symptom-limited cardiopulmonary exercise testing (CPET) in CHF patients. Stable CHF patients (N = 42; 54 ± 10 years [mean ± SD], 35 males) participated in an exercise training program for 12 weeks, 3 times per week. Participants were randomly assigned to either AIT (n = 20) or COM group (n = 22). Cardiopulmonary exercise testing was performed before and after completion of the program. Primary measurements included absolute and percentage difference of oxygen uptake, carbon dioxide output, minute ventilation ((Equation is included in full-text article.)E), tidal volume (VT), respiratory rate, and the first-degree slope of oxygen uptake ((Equation is included in full-text article.)O2/t slope) and carbon dioxide output ((Equation is included in full-text article.)CO2/t slope) during the first minute of recovery after maximal exercise. The COM group had a greater improvement in the absolute and the percentage difference of (Equation is included in full-text article.)E (P = .03 and P = .04, respectively) and respiratory rate (P = .02 and P = .01, respectively) during the first minute of recovery period after exercise compared with the AIT group alone. No significant changes were noted for VT measurements. A significant increase in (Equation is included in full-text article.)CO2/t slope was observed in COM compared with the AIT group (P = .01). There was a trend for a greater increase in (Equation is included in full-text article.)O2/t slope in the COM group (P = .07). The addition of strength training to AIT induces significant beneficial effects in terms of ventilatory and metabolic recovery kinetics than AIT alone in CHF patients, possibly indicating greater ventilatory efficiency and metabolic improvement.

Effects of Nonlinear Resistance and Aerobic Interval Training on Cytokines and Insulin Resistance in Sedentary Men Who Are Obese

Regular exercise training has been shown to reduce systemic inflammation, but there is limited research directly comparing different types of training. The purpose of this study was to compare the effects of nonlinear resistance training (NRT) and aerobic interval training (AIT) on serum interleukin-10 (IL-10), IL-20, and tumor necrosis factor-α (TNF-α) levels, insulin resistance index (homeostasis model assessment of insulin resistance), and aerobic capacity in middle-aged men who are obese. Sedentary volunteers were assigned to NRT (n = 12), AIT (n = 12), and (CON, n = 10) control groups. The experimental groups performed 3 weekly sessions for 12 weeks, whereas the CON grouped maintained a sedentary lifestyle. Nonlinear resistance training consisted of 40-65 minutes of weight training at different intensities with flexible periodization. Aerobic interval training consisted of running on a treadmill (4 sets of 4 minutes at 80-90% of maximal heart rate, with 3-minute recovery intervals). Serum IL-10, IL-20, and TNF-α levels did not change significantly in response to training (all p > 0.05), but IL-10:TNF-α ratio increased significantly with AIT compared with CON (2.95 ± 0.84 vs. 2.52 ± 0.65; p = 0.02). After the training period, maximal oxygen uptake increased significantly in AIT and NRT compared with CON (both p < 0.001; 46.7 ± 5.9, 45.1 ± 3.2, and 41.1 ± 4.7 ml·kg·min, respectively) and in AIT than in NRT (p = 0.001). The 2 exercise programs were equally effective at reducing insulin resistance (homeostasis model assessment for insulin resistance) (both p ≤ 0.05; AIT: 0.84 ± 0.34, NRT: 0.84 ± 0.27, and CON: 1.62 ± 0.56) and fasting insulin levels (both p ≤ 0.05; AIT: 3.61 ± 1.48, NRT: 3.66 ± 0.92, and CON: 6.20 ± 2.64 μU·ml), but the AIT seems to have better anti-inflammatory effects (as indicated by the IL-10:TNF-α ratio) compared with NRT.

Validation of rate of perceived exertion-based exercise training in patients with heart failure: Insights from autonomic nervous system adaptations

BackgroundExercise prescription in cardiac patients is based on heart rate (HR) response to exercise. How to prescribe long-term exercise training outside medically-supervised settings also considering changes in individual physical capacity over time is unknown. In this study we hypothesized that in patients with chronic heart failure (CHF) the session-rate of perceived exertion (RPE), a subjective-based training methodology, provides autonomic and functional capacity changes superimposable to those observed with HR-based Training Impulses (TRIMPi) method. MethodsTwenty patients with stable CHF were randomized to either aerobic continuous training (ACT) or aerobic interval training (AIT) for 12weeks. For each TRIMPi-guided exercise session, the session-RPE was recorded. By this method, internal training load (TL) is quantified by multiplying the RPE of the whole training session, using the Borg CR10-scale, by its duration. Heart rate variability (HRV), and baroreflex sensitivity (BRS) were assessed at baseline and at 3weeks intervals. ResultsSignificant correlations were found between TRIMPi and individual session-RPE, for both ACT and AIT (r=0.63 to 0.81), (P<0.05). The same occurred when ACT and AIT groups were pooled together (r=0.72; P<0.01). R–R interval, HRV and BRS were significantly and very highly correlated with weekly RPE-session (r2 ranged from 0.77 to 0.97; P<0.001). A significant relationship between session-RPE and performance at the 6MWT was also found. ConclusionsSession-RPE is an easy-to-use, inexpensive and valid method for exercise prescription and health maintenance, consistent with objective physiological indices of training, that could be used for long-term physical activity in patients with CHF.

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.