Effects Of Chronic Aerobic Exercise Research Articles

Effects of chronic aerobic exercise on attentional bias among women with methamphetamine addiction

ObjectiveTo explore the effects of chronic exercise on attentional bias toward drug-related stimuli and on brain electrophysiological characteristics among women with methamphetamine addiction. MethodsIn total, 63 women with methamphetamine addiction were randomized to participate in a dance (n = 21; mean age, 32.16 ± 2.07 years), bicycle (n = 21; mean age, 32.59 ± 2.12 years), or control (maintained regular activities with little exercise; n = 21; mean age, 30.95 ± 2.81 years) group for 12 weeks. The participants in the three groups were not significantly different in terms of methamphetamine use or detoxification. Before and after the intervention, attentional bias was assessed using the dot-probe task, and event-related potentials were recorded during the task. ResultsThe mean attentional bias scores decreased significantly after the intervention in both exercise groups but not in the control group. After 12 weeks of dance exercise, the amplitudes of the N170, N2, P2, and P3 components of the event-related potentials decreased significantly during attentional bias processing. In addition, differences in N170 amplitudes for congruent vs. incongruent conditions in the dot-probe task were no longer observed. After 12 weeks of cycling exercise, N2 and P2 amplitudes decreased significantly. By contrast, there were no significant differences in N170, N2, P2, and P3 amplitudes in the control group before vs. after the intervention. ConclusionsChronic (12 weeks of) aerobic exercise reduced attentional bias toward drug-related cues by improving attentional inhibition and reducing the maintenance of extra attention to drug-related cues among women with methamphetamine addiction. Both dance and bicycle exercise improved the early recognition of drug-related cues, weakened the influence of the memory of previous drug use, and improved attentional bias behavior by strengthening attention control. Dance exercise, but not bicycling, also regulated emotional control and improved the attention selection process. These results provide theoretical and empirical evidence that chronic aerobic exercise may reduce the attentional bias toward drug-related cues to assist in the recovery of women with methamphetamine addiction.

Brain Mapping the Effects of Chronic Aerobic Exercise in the Rat Brain Using FDG PET

Exercise is a key component to health and wellness and is thought to play an important role in brain activity. Changes in brain activity after exercise have been observed through various neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). The precise impact of exercise on brain glucose metabolism (BGluM) is still unclear; however, results from PET studies seem to indicate an increase in regional metabolism in areas related to cognition and memory, direction, drive, motor functions, perception, and somatosensory areas in humans. Using PET and the glucose analog [18F]-Fluorodeoxyglucose (18F-FDG), we assessed the changes in BGluM between sedentary and chronic exercise in rats. Chronic treadmill exercise treatment demonstrated a significant increase in BGluM activity in the following brain regions: the caudate putamen (striatum), external capsule, internal capsule, deep cerebellar white matter, primary auditory cortex, forceps major of the corpus callosum, postsubiculum, subiculum transition area, and the central nucleus of the inferior colliculus. These brain regions are functionally associated with auditory processing, memory, motor function, and motivated behavior. Therefore, chronic daily treadmill running in rats stimulates BGluM in distinct brain regions. This identified functional circuit provides a map of brain regions for future molecular assessment which will help us understand the biomarkers involved in specific brain regions following exercise training, as this is critical in exploring the therapeutic potential of exercise in the treatment of neurodegenerative disease, traumatic brain injury, and addiction.

Acute and chronic effects of aerobic exercise on serum irisin, adropin, and cholesterol levels in the winter season: Indoor training versus outdoor training.

The aim of this study is to investigate the acute and chronic effects of aerobic training performed indoors and outdoors on irisin, adropin, and cholesterol levels in winter. Thirty-two healthy males participated in this study. Participants were divided into two groups: outdoor group (n = 16) and indoor group (n = 16). They then performed 40-min aerobic running exercises 4 days/week for 18 weeks. The outdoor group trained at -5°C-5°C environmental temperature, while the indoor group trained at 21°C-25°C. Blood samples were collected before and after the 18-week training period and immediately after the first training. The results showed that single aerobic exercise induced minimal increase in serum irisin concentrations in both groups. In addition, irisin levels did not change in the outdoor group but significantly decreased in the indoor group after the 18-week training period. Aerobic exercise had no acute or chronic effects on serum adropin levels in the indoor group. However, the aerobic training caused a decrease in adropin levels chronically, but there was no acute effect after single aerobic exercise in the outdoor group. Furthermore, there was no acute effect on high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, and total cholesterol after single aerobic exercise in both groups. However, after the 18-week training period, there was a significant increase in HDL-C levels in both groups. Moreover, the increase in HDL-C in the outdoor group was higher than in the indoor group. Thus, this study provides evidence for the beneficial chronic effects of aerobic exercise and cold on HDL-C levels as well as the beneficial acute effects on irisin concentrations.

Chronic aerobic exercise improves insulin sensitivity and modulates Nrf2 and NF‑κB/IκBα pathways in the skeletal muscle of rats fed with a high fat diet.

The present study aimed to investigate the molecular mechanisms of the ameliorative effects of chronic aerobic exercise on non-alcoholic steatohepatitis (NASH) in rat skeletal muscle. Female Sprague-Dawley rats (n=6–9 per group) were divided into four groups: i) Rats fed with normal chow; ii) exercise rats fed with normal chow + exercise (run on a rotarod for 30 min per day from 9–12 weeks); iii) rats fed with a high-fat diet (HFD); iv) rats fed with an HFD + exercise. All HFD rats were fed with an HFD consisting of 30% fat from fish oil throughout the study for 12 weeks. Exercise decreased the levels of hepatic lipogenic markers carbohydrate-responsive element-binding protein, fat-specific protein 27 and liver X receptor and improved systemic glucose and insulin intolerance in the NASH animal model. The beneficial effects may have been mediated partly via the tripartite motif-containing family protein 72 (TRIM72)/PI3K/Akt/mTOR pathway, accompanied with an upregulation of glucose transporter 4 in the skeletal muscle. The exercise regimen activated the master regulator of antioxidant enzymes, nuclear factor erythroid 2-related factor 2, with upregulation of superoxide dismutase [Cu-Zn] expression and a corresponding decrease in kelch-like ECH-associated protein 1 expression, but failed to decrease the levels of the oxidative marker malondialdehyde in the HFD rat skeletal muscle. Chronic exercise decreased the expression of the inflammation marker NF-κB, followed by a decrease in interleukin-6 and tumor necrosis factor-α levels, as verified by a corresponding increase in the level of NF-κB inhibitor α expression. Exercise may exert its beneficial effects by improving muscle insulin sensitivity via the TRIM72/PI3K/Akt/mTOR pathway, contributing to the improvement of systemic insulin intolerance, and finally leading to decreased hepatic lipogenesis during NASH. The attenuation of insulin resistance by exercise may be partly achieved through a decrease in the level of inflammation and an increased antioxidant response.

Influence of different rehabilitative aerobic exercise programs on (anti-) inflammatory immune signalling, cognitive and functional capacity in persons with MS \u2013 study protocol of a randomized controlled trial

BackgroundStudies have shown positive effects of therapeutic exercise on motor- and cognitive function as well as on psychosocial outcomes in persons with multiple sclerosis (MS). A reduction of inflammatory stress through physical exercise has been suspected as one key mechanism, mediating the positive effects of exercise in the context of MS. The primary objective of this trial is to investigate the acute and chronic effects of different exercise modalities on (anti-)inflammatory immune signalling as well as on cognitive and functional capacity in persons with MS.MethodsA two armed single-blind randomized controlled design will investigate 72 persons with relapsing remitting or secondary progressive MS (EDSS 3.0–6.0), during 3 weeks of inpatient rehabilitation. Participants will be randomized into either a high-intensity interval training (HIIT) or a moderate continuous training group; the latter represents the local standard therapy (ST). Both groups will exercise 3x per week. The HIIT group will perform 5 × 1.5-min high-intensive exercise bouts at 95–100% of their maximum heart rate (HRmax) followed by active breaks of unloaded pedalling (60% HRmax) for 2 min. In contrast, the ST group will exercise for 24 min continuously at 65% of HRmax. The proportion of circulating regulatory T-cells will be measured as primary outcome. Secondary outcomes comprise numbers and proportions of further immune cells including Th17-cells, soluble factors ((anti-) inflammatory cytokines, tryptophan metabolites), endurance capacity, cognitive performance, processing skills for activities of daily living, fatigue, depression and healthcare-related quality of life. Outcomes will be assessed before (T0) and after (T3) the 3-week exercise intervention program. Blood samples of T0 will be taken immediately before the first exercise session. Additionally, blood samples for the soluble factors will be collected immediately after (T1) and three hours (T2) after the first exercise session of each group.DiscussionThis study will be the first to investigate both acute and chronic effects of aerobic exercise on immune function and disease associated biomarkers in persons with MS. Combining biological analyses with cognitive and functional capacity assessments may contribute to a better understanding of responses to rehabilitative training, needed to improve exercise recommendations for persons with MS.Trial registrationThis trial was prospectively registered at ClinicalTrials.gov (NCT03652519; 29 August 2018).

Effects of a Ketogenic Diet and Chronic Aerobic Exercise on C57BL6 Mice

INTRODUCTIONLow carbohydrate ketogenic diets (LCKD) alter metabolic processes and have been proposed as a means to attenuate adiposity and reduce hyperglycemia. Aerobic exercise training promotes a suite of metabolic adaptations effective in reducing the incidence of metabolic syndrome. There is potential for combined LCKD and aerobic exercise training to alter substrate metabolism in a manner that could enhance body composition. To investigate whether a LCKD could favorably alter metabolic function and potentiate the effects of chronic aerobic exercise, mice were fed a LCKD for a total of 7 weeks, while during the final 3 weeks half of the mice concurrently engaged in daily treadmill exercise.METHODS40 C57BL6 mice were randomized into 4 groups (n=10/group): 2 groups were fed a low‐fat control diet (16% protein, 72% carbohydrate, 12% fat) with one group performing vigorous intensity (blood lactate >4mM post‐exercise) daily treadmill exercise (CEX) and the other serving as sedentary controls (CSED). The remaining 2 groups were fed a LCKD (84% fat, 16% protein) with one exercise group (KEX) and a group of sedentary controls (KSED). Body composition (NMR) was measured weekly. At the end of the 4 week exercise training program, mice were euthanized and substrate oxidation was assessed using 14C labelled substrates, while blood was analyzed for lipids, glucose and β‐OHB.RESULTSThe LCKD resulted in a mild increase in circulating ketones; however, mice on this diet did not exhibit differences in serum fatty acids, triglycerides (TG), or glucose levels despite consuming a lipid‐enriched, carbohydrate‐deficient diet. Body weight and fat mass increased in response to the LCKD, but exercise training limited weight gain. A LCKD did not alter TG levels in liver or muscle; however, exercise training increased TG accrual in both tissues and this effect was more prominent in mice fed the control diet. In the liver, LCKD reduce carbohydrate oxidation, but increased leucine oxidation, incomplete palmitate oxidation, and peroxisomal oxidation. Alternatively, in skeletal muscle carbohydrate oxidation did not change in response to LCKD, whereas mitochondrial and peroxisomal fat oxidation both increased. Exercise training had minimal effect on hepatic substrate oxidation, but increased oxidation of leucine, palmitate, and lignocerate in skeletal muscle; however, no synergistic effects were detected between a ketogenic diet and exercise training.CONCLUSIONOur results indicate that mice fed an 84% fat, 16% protein diet demonstrate a shift in substrate utilization toward an increased reliance on fatty acid and branch‐chain amino acid catabolism in liver and skeletal muscle, while vigorous‐intensity exercise effects were more prominent in muscle. Despite the fact that both LCKD and exercise independently induced shifts in substrate metabolism, the effects do not appear to be additive or synergistic and mice fed an LCKD retained greater adiposity than mice fed a protein‐matched control dietSupport or Funding InformationThis work was supported by NIH R01 DK103860‐01 (R.C.N).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of Aerobic Exercise on Anxiety Symptoms and Cortical Activity in Patients with Panic Disorder: A Pilot Study.

Background:The effects of the aerobic exercise on anxiety symptoms in patients with Panic Disorder (PD) remain unclear. Thus, the investigation of possible changes in EEG frontal asymmetry could contribute to understand the relationship among exercise, brain and anxiety.Objective:To investigate the acute effects of aerobic exercise on the symptoms of anxiety and the chronic effects of aerobic exercise on severity and symptoms related to PD, besides the changes in EEG frontal asymmetry.Methods:Ten PD patients were divided into two groups, Exercise Group (EG; n=5) and Control Group (CG; n=5), in a randomized allocation. At baseline and post-intervention, they submitted the psychological evaluation through Panic Disorder Severity Scale (PDSS), Beck Anxiety Inventory (BAI), Beck Depression Inventory-II (BDI-II), EEG frontal asymmetry, and maximal oxygen consumption (VO2max). On the second visit, the patients of EG being submitted to the aerobic exercise (treadmill, 25 minutes, and 50-55% of heart rate reserve) and the CG remained seated for the same period of time. Both groups submitted a psychological evaluation with Subjective Units of Distress Scale (SUDS) at baseline, immediately after (Post-0), and after 10 minutes of the rest pause (Post-10). The patients performed 12 sessions of aerobic exercise with 48-72 hours of interval between sessions.Results:In EG, SUDS increased immediately after exercise practice and showed chronic decrease in BAI and BDI-II as well as increased in VO2max (Post-intervention).Conclusion:Aerobic exercise can promote increase in anxiety acutely and regular aerobic exercise promotes reduction in anxiety levels.

The Effects of Chronic Aerobic Exercise on Cardiovascular Risk Factors in Persons with Diabetes Mellitus.

Aerobic exercise training is a component of diabetes mellitus (DM) care guidelines due to its favorable effects on glycemic control and cardiovascular disease (CVD) risk factors. The purpose of this review is to outline the recent evidence regarding the clinical effects of chronic aerobic exercise on CVD risk factors in persons with DM and to compare the effects of varying intensities and types of exercise. Among individuals with DM, all types of aerobic exercise training can impact positively on some traditional and non-traditional risk factors for CVD. Training programs with a higher volume or intensity induce greater improvements in vascular function, cardiorespiratory fitness (CRF), and lipid profiles. The beneficial outcomes of aerobic training include improvements in glycemic control, endothelial function, oxidative stress, dyslipidemia, myocardial function, adiposity, and CRF. Findings regarding markers of inflammation are discrepant and further research should focus on the role of exercise to impact upon the chronic inflammation associated with DM.

Acute and chronic effects of aerobic exercise on blood pressure in resistant hypertension: study protocol for a randomized controlled trial

BackgroundResistant hypertension is a specific condition that affects approximately 10% of subjects with hypertension, and is characterized by persistently high blood pressure levels even using therapy of three or more antihypertensive agents or with blood pressure control using therapy with four or more antihypertensive agents. Changes in lifestyle, such as physical exercise, are indicated for controlling blood pressure. However, investigating studies about this therapy in individuals with resistant hypertension are few.Methods/designThis is a randomized controlled clinical trial. Forty-eight patients with resistant hypertension will be submitted to perform four short-term interventions: aerobic exercise sessions (mild-, moderate- and high-intensity) and control session, in random order and on separate days. After the short-term sessions, the patients will be randomly allocated into four groups for 8 weeks of follow-up: mild-, moderate- and high-intensity aerobic exercise, and a control group. The primary outcome is the occurrence of blood pressure reduction (office and ambulatory analysis, and acute and chronic effects). Secondary outcomes are autonomic and hemodynamic mechanisms: cardiac and vasomotor autonomic modulation, spontaneous baroreflex sensitivity, forearm blood flow and vascular resistance.DiscussionThe importance of exercise for hypertension has been known for decades, but little is known about the effects on patients with resistant hypertension. This study will help to understand whether different aerobic exercise intensities can induce different responses, as well as by what mechanisms adjustments in blood pressure levels may occur.Trial registrationClinicalTrials.gov, ID: NCT02670681. Registered on 28 January 2016 (first version); Brazilian Registry Platform Clinical Trials: protocol RBR-5q24zh. Registered on 24 June 2015.

Abstract P048: Effects of Aerobic Exercise on Oxidative Stress in the Kidneys of Type2 Diabetic Rats

Objective: Aerobic exercise is known to have multiple beneficial effects including renal protection in type 2 diabetes mellitus and obesity. However, the mechanisms regulating these actions of aerobic exercise remain unclear. The present study evaluated the effects of chronic aerobic exercise on early stage of diabetic nephropathy focusing on renal oxidative stress and nitric oxide (NO), using Zucker diabetic fatty (ZDF) rats as an animal model of obese type 2 diabetes. Methods: Male ZDF rats (6 weeks old) underwent forced treadmill exercise for 8 weeks (Ex-ZDF). Sedentary ZDF (Sed-ZDF) and Zucker lean (Sed-ZL) rats served as controls. After the last exercise session, all rats were subjected to an intra-peritoneal glucose tolerance test. Result: Exercise ameliorated hyperglycemia with increased insulin secretion, and raised the values of homeostasis model assessment for β-cell function (HOMA-β) in ZDF rats. Exercise also reduced albumin excretion and normalized creatinine clearance in ZDF rats. Endothelial (e) and neuronal (n) NO synthase (NOS) protein expression, and NOS activity in the kidneys of Sed-ZDF rats were lower compared with Sed-ZL rats, while both NOS expression and NOS activity were upregulated by exercise in ZDF rats. Although there was no significant difference in plasma levels of adiponectin between the groups, plasma levels of leptin were significantly higher in the Ex-ZDF group compared with the Sed-ZL and Sed-ZDF groups. Exercise decreased plasma and urinary thiobarbituric acid-reactive substances (TBARS) as an index of lipid peroxidation in ZDF rats. Additionally, renal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and expression of p47phox protein were significantly higher in the kidneys of the Sed-ZDF group compared with the Sed-ZL group, and there was no significant difference between the Ex-ZDF and Sed-ZL groups. Immunoblots for Nox4, Nox2, namely gp91phox and p22phox protein were undetected in the kidneys of the Sed-ZDF and Ex-ZDF group as well as the Sed-ZL group. In addition, expression of nitrotyrosine as an index of peroxynitrite (ONOO–) formation was significantly lower in the kidneys of the Sed-ZDF group compared with the Sed-ZL group, and was significantly higher in the Ex-ZDF group compared with the Sed-ZDF group. Further, morphometric evidence of renal damage was alleviated in response to exercise. Conclusion: Upregulated NOS activity and NOS protein, and ameliorated NADPH oxidase activity and p47phox protein in the kidneys may be potential mechanisms by which chronic aerobic exercise can reduced early diabetic nephropathy in ZDF rats. Chronic aerobic exercise does have beneficial effects and may be a novel therapeutic approach for preventing the development of renal dysfunction in patients with type 2 diabetes mellitus and obesity.

Aerobic Exercise Does Not Predict Brain Derived Neurotrophic Factor And Cortisol Alterations in Depressed Patients.

The pathophysiology of depression is related to neurobiological changes that occur in the monoamine system, hypothalamic-pituitary-adrenal axis, neurogenesis system and the neuroimmune system. In recent years, there has been a growing interest in the research of the effects of exercise on brain function, with a special focus on its effects on brain-derived neurotrophic factor (BDNF), cortisol and other biomarkers. Thus, the aim of this study is to present a review investigating the acute and chronic effects of aerobic exercise on BDNF and cortisol levels in individuals with depression. It was not possible to establish an interaction between aerobic exercise and concentration of BDNF and cortisol, which may actually be the result of the divergence of methods, such as type of exercises, duration of the sessions, and prescribed intensity and frequency of sessions.

Chronic effects of aerobic exercise on gene expression of LOX-1 receptor in the heart of rats fed with high fat diet.

Lectin-like low density lipoprotein receptor (LOX-1) has pivot role in vascular complications, which is upregulated in numerous pathological conditions. Since exercise has beneficial effects in prevention of hyperlipidemic complications, present study examined protective effects of aerobic exercise through reduction of LOX-1 expression in heart during dyslipidemia. Four groups of rats were used (N=25): Normal, Normal and exercise, High fat and High fat and exercise. High fat diet (HFD) was made by adding 10% animal oil, 2% cholesterol and 0.5% colic acid to standard rodent chow. Exercise protocol consisted of swimming 1 hr/day, and 5 days/week for 8 weeks. Plasma lipids were evaluated at the end of experiment, 48 hr after final session of exercise. At the end, rats were sacrificed and heart was removed for determination of malondialdehyde (MDA) content, and LOX-1 expression. HFD meaningfully changed lipid profile (>50%), but chronic exercise had no significant effects on lipid profile. LOX-1 expression was significantly increased in heart of rats fed with HFD, while swimming exercise considerably reduced gene expression of LOX-1. MDA content was significantly enhanced in rats fed with HFD (4.37±0.6 nmol/mg, P<0.01) compared to normal group (1.56±0.48 nmol/mg), whereas swimming exercise decreased MDA level of heart in rats fed with HFD (2.28±0.32, P<0.01). Findings indicated that swimming exercise is able to diminish heart expression of LOX-1 receptor concomitant reduction of oxidative stress. Since these parameters are involved in generation of dyslipidemic complications, swimming exercise is a good candidate to reduce these complications.

Chronic effects of aerobic exercise on panic disorder: a systematic review of randomized and non-randomized trials

BACKGROUND: In general, most studies have supported an association between the acute effects of exercise and a reduced state anxiety, but failed to completely explain the relationship between the chronic effect of exercise and anxiety traits. OBJECTIVE: The aim of this study was to systematically review the literature regarding the chronic effect of exercise on symptoms associated with panic disorder. METHODS: The studies were retrieved from a MEDLINE/PubMed, ISI Web of Knowledge and SciELO. We adopted PICOS’s strategy recommended to determine the eligibility criteria. The survey was conducted using an advanced search in the ISI Web of Science and MEDLINE / PubMed with MeSH terms and Entry Terms for the keywords “Panic Disorder” basis and “Exercise”. Boolean operators “AND” and “OR” were used separately or in combination. Two independent researchers performed the selection of studies; in case of disagreement they sought a consensus on the selection. RESULTS: A total of 265 articles were identified: 199 articles from PubMed/Medline, 63 articles from ISI Web of Science and 3 articles by manual searches. Thus, 31 articles were analyzed by the eligibility criteria and the exclusion criteria, a total of five studies included in the systematic review. CONCLUSION: The regular practice of aerobic exercise seems to be an appropriate intervention to promote improvements in the severity of anxiety symptoms in PD patients.

Therapeutic Properties of Aerobic Training After a Cancer Diagnosis: More Than a One-Trick Pony?

Until recently there was a prevailing dogma that cancer patients may be unable to safely participate in, benefit from, or tolerate structured exercise training/rehabilitation. Nevertheless, two factors pointed to the potential benefit of exercise in cancer patients: 1) the robust efficacy of exercise to favorably impact multiple physiological and psychosocial outcomes in noncancer clinical populations with similar symptomatology and limitations to exercise and 2) the emergence and importance of cancer survivorship. These factors provided the ideal platform and rationale to launch initial studies testing the safety, tolerability, and efficacy of exercise in patients with cancer (1). The past decade has witnessed a relative explosion in research, as well as clinical interest, in the application of exercise, as well as more general physical activity, in the context of cancer control efforts (1).

The acute aerobic exercise‐induced increase in amino acid transporter expression adapts to exercise training in older adults

Exercise and nutritional interventions may prevent or delay frailty and sarcopenia in older adults. The OBJECTIVE of this ongoing study is to determine the acute and chronic effects of aerobic exercise +/− essential amino acid (EAA) supplementation on skeletal muscle amino acid (AA) transporter expression. Preliminary data are reported.METHODSHealthy untrained older adults (65–85 y; n=10) were randomized into one of two groups: exercise and 15 g EAA supplement (Ex+EAA) or exercise and placebo (Ex+Pla). Acute treatment consisted of 45 mins of walking exercise on a treadmill at ~70% heart rate max (Ex+EAA and Ex+Pla) immediately followed by the assigned supplement or placebo. Chronic treatment involved once daily supplementation (EAA or Pla) plus aerobic exercise 3 times/wk. Real‐time qPCR was used to measure mRNA expression of select muscle AA transporters.RESULTSAt baseline, CAT1, SNAT2, PAT1, CD98, and LAT1 mRNA expression increased more after Ex+EAA than Ex+Pla. After chronic treatment, only CD98 increased with Ex+EAA. There were no basal pre to post changes.CONCLUSIONMuscle AA transporter expression increases acutely with Ex+EAA. Exercise training+EAA induces adaptations reducing the acute AA transporter response to these stimuli. Supported by NIH/NIA R01 AG030070 and NIH/NIA R01 AG030070S1Grant Funding Source: NIH

Low and moderate, rather than high intensity strength exercise induces benefit regarding plasma lipid profile

BackgroundThe effects of chronic aerobic exercise upon lipid profile has been previously demonstrated, but few studies showed this effect under resistance exercise conditions.ObjectiveThe aim of this study was to examine the effects of different resistance exercise loads on blood lipids.MethodsThirty healthy, untrained male volunteers were allocated randomly into four groups based at different percentages of one repetition maximum (1 RM); 50%-1 RM, 75%-1 RM, 90%-1 RM, and 110%-1 RM. The total volume (sets × reps × load) of the exercise was equalized. The lipid profile (Triglycerides [TG], HDL-cholesterol [HDL-c], LDL-cholesterol, and Total cholesterol) was determined at rest and after 1, 24, 48 and 72 h of resistance exercise.ResultsThe 75%-1 RM group demonstrated greater TG reduction when compared to other groups (p < 0.05). Additionally, the 110%-1 RM group presented an increased TG concentration when compared to 50% and 75% groups (p = 0.01, p = 0.01, respectively). HDL-c concentration was significantly greater after resistance exercise in 50%-1 RM and 75%-1 RM when compared to 110%-1 RM group (p = 0.004 and p = 0.03, respectively). Accordingly, the 50%-1 RM group had greater HDL-c concentration than 110%-1 RM group after 48 h (p = 0.05) and 72 h (p = 0.004), respectively. Finally, The 50% group has showed lesser LDL-c concentration than 110% group after 24 h (p = 0.007). No significant difference was found in Total Cholesterol concentrations.ConclusionThese results indicate that the acute resistance exercise may induce changes in lipid profile in a specific-intensity manner. Overall, low and moderate exercise intensities appear to be promoting more benefits on lipid profile than high intensity. Long term studies should confirm these findings.

Chronic aerobic exercise enhances components of the classical and novel insulin signalling cascades in Sprague–Dawley rat skeletal muscle

The aim of this study was to provide a more extensive evaluation of the effects of chronic aerobic exercise on various components of the insulin signalling cascade in normal rodent skeletal muscle because of the limited body of literature that exists in this area of investigation. Male Sprague-Dawley rats were assigned to either control (n = 7) or chronic aerobic exercise (n = 7) groups. Aerobic exercise animals were run 3 day week(1) for 45 min on a motor-driven treadmill (32 m min(1), 15% grade) for a 12 week period. Following the training period, all animals were subjected to hind limb perfusion in the presence of 500 microU mL(1) insulin to determine what effect chronic aerobic training had on various components of the insulin signalling cascade, c-Cbl protein concentration and c-Cbl phosphorylation. Twelve weeks of aerobic training did not alter skeletal muscle Akt 1/2 protein concentration, Akt Ser 473 phosphorylation, Akt Thr 308 phosphorylation, Akt 1 activity, aPKC-zeta protein concentration, aPKC-lambda protein concentration or c-Cbl protein concentration. In contrast, chronic aerobic exercise increased insulin-stimulated phosphatidylinositol 3-kinase, Akt 2 kinase and aPKC-zeta/lambda kinase activities, as well as c-Cbl tyrosine phosphorylation, in a fibre type specific response to aerobic training. In addition, chronic aerobic exercise enhanced insulin-stimulated plasma membrane glucose transporter 4 (GLUT4) protein concentration. Collectively, these findings suggest that chronic aerobic exercise enhances components of both the classical and novel insulin signalling cascades in normal rodent skeletal muscle, which may contribute to an increased insulin-stimulated plasma membrane GLUT4 protein concentration.

Effects of Chronic Aerobic Exercise on Skeletal Muscle Uncoupling Protein 3

1257 Skeletal muscle uncoupling protein 3 (UCP3) is thought to uncouple oxidative phosphorylation from ATP production and therefore contribute to whole body energy metabolism. UCP3 may also have a role in the pathophysiology of obesity. It has been hypothesized that the increase in energy efficiency associated with endurance training is a result of decreased skeletal muscle UCP3. However, we have recently demonstrated that endurance training does not down regulate UCP3 mRNA. Although we did not expect changes in UCP3 protein levels it is possible that UCP3 could be regulated post-transcriptionally by endurance training. There is a lack of data that addresses the effects of exercise training on UCP3 protein levels. PURPOSE: To determine the chronic effects of aerobic exercise on basal UCP3 protein levels in endurance trained rats. METHODS: Fifteen Sprague Dawley rats were randomly assigned to control (C, n = 8) or endurance training (T, n = 7) groups. T rats trained five days weekly for a period of eight weeks on a motorized treadmill. T rats ran at 28 m/min for approximately 60 minutes per day. All rats were sacrificed 48 hours after the final training session. The soleus muscle was rapidly removed, frozen in liquid nitrogen and stored at −80° C until analysis. UCP3 levels were estimated by western blots and the optical density and area of the resultant bands was determined. Citrate synthase activity (CS) was also determined and used as a measure of aerobic conditioning. RESULTS: CS activity (nmol/mg prot./min) was significantly higher (P = 0.027) after training in the soleus muscle of T versus C. Basal UCP3 protein levels did not differ (P = 0.8) between T and C animals in the soleus muscle. CONCLUSIONS: These data suggest that eight weeks of treadmill running in rats which produced a significant aerobic training effect as measured by CS activity does not down regulate the basal protein levels of UCP3 at least in the predominantly slow twitch soleus muscle.

Protein malnutrition does not impair glucose metabolism adaptations to exercise-training

Malnutrition is a common health problem in developing countries and is associated with alterations in glucose metabolism. In the present study we examine the effects of chronic aerobic exercise on some aspects of glucose metabolism in protein-deficient rats. Two groups of adult rats (90 days old) were used: Normal protein group (17%P)- kept on a normal protein diet during intra-uterine and postnatal life and Low protein group (6%P)- kept on a low protein diet during intra-uterine and post natal life. After weaning (21 days old), half of the 17%P and 6%P rats were assigned to a Sedentary (Sed) or an Exercise-trained (Exerc = swimming, 1 hr/day, 5 days/week, supporting an overload of 5% of body weight) subgroup. The area under blood glucose concentration curve (ΔG) after an oral glucose load was higher in 17%P Sed rats (20%) than in other rats and lower in 6%P Exerc (11%) in relation to 6% Sed rats. The post-glucose increase in blood insulin (ΔI) was also higher in 17%P Sed (9%) than in other rats. On the other hand, the glucose disappearance rate after exogenous subcutaneous insulin administration (Kitt) was lower in 17%P Sed rats (66%) than in other rats. Glucose uptake by soleus muscle was higher in Exerc rats (30%) than in Sed rats. Soleus muscle glycogen synthesis was reduced in 6%P Sed rats (41%) compared to 17%P Sed rats but was restored in 6%P Exerc rats. Glycogen concentration was elevated in Exerc (32%) rats in comparison to Sed rats. The present results indicate that glucose-induced insulin release is reduced in rats fed low protein diet. This defect is counteracted by an increase in the sensitivity of the target tissues to insulin and glucose homeostasis is maintained. This adaptation allows protein deficient rats to preserve the ability to appropriately adapt to aerobic physical exercise training.