Moderate-intensity Training Research Articles

Moderate-intensity exercise versus high-intensity interval training to recover walking post-stroke: protocol for a randomized controlled trial

BackgroundStroke results in neurologic impairments and aerobic deconditioning that contribute to limited walking capacity which is a major barrier post-stroke. Current exercise recommendations and stroke rehabilitation guidelines recommend moderate-intensity aerobic training post-stroke. Locomotor high-intensity interval training is a promising new strategy that has shown significantly greater improvements in aerobic fitness and motor performance than moderate-intensity aerobic training in other populations. However, the relative benefits and risks of high-intensity interval training and moderate-intensity aerobic training remain poorly understood following stroke. In this study, we hypothesize that locomotor high-intensity interval training will result in greater improvements in walking capacity than moderate-intensity aerobic training.MethodsUsing a single-blind, 3-site randomized controlled trial, 50 chronic (> 6 months) stroke survivors are randomly assigned to complete 36 locomotor training sessions of either high-intensity interval training or moderate-intensity aerobic training. Main eligibility criteria are age 40–80 years, single stroke for which the participant received treatment (experienced 6 months to 5 years prior to consent), walking speed ≤ 1.0 m/s, able to walk at least 3 min on the treadmill at ≥ 0.13 m/s (0.3 mph), stable cardiovascular condition (American Heart Association class B), and the ability to walk 10 m overground without continuous physical assistance. The primary outcome (walking capacity) and secondary outcomes (self-selected and fast gait speed, aerobic fitness, and fatigue) are assessed prior to initiating training and after 4 weeks, 8 weeks, and 12 weeks of training.DiscussionThis study will provide fundamental new knowledge to inform the selection of intensity and duration dosing parameters for gait recovery and optimization of aerobic training interventions in chronic stroke. Data needed to justify and design a subsequent definitive trial will also be obtained. Thus, the results of this study will inform future stroke rehabilitation guidelines on how to optimally improve walking capacity following stroke.Trial registrationClinicalTrials.govNCT03760016. Registered on November 30, 2018.

Effects of High and Moderate-Intensity Interval Training on Pulmonary and Performance Parameters in Miners Suffering From Chronic Obstructive Pulmonary Diseases.

To characterize the effect of 12 weeks of high and moderate-intensity interval training on pulmonary and functional parameters in miners with chronic obstructive pulmonary disease working in the polluted environment. Forty-five miners with COPD (average degree: 60 > FEV1 < 70), were randomly divided into HIIT (with 100%-125% ISWT); MIIT (with 60%-85% ISWT), and control. The study period was 12 weeks (3 sessions per week). At the beginning and end of the study, pulmonary and functional indices was evaluated. Based on results, HIIT and MIIT significantly increased FVC, FEV1, and mean traveled distance in ISWT compared with control. Comparison of training intensities showed that HIIT led to a significant change in FVC, FEV1, and ISWT record compared to MIIT. It is suggested that miners suffering from COPD, consider HIIT as part of their treatment plan.

Moderate-intensity aerobic training reduces cardiac damage attributable to experimental iron overload in rats.

What is the central question of this study? The current literature indicates that oxidative stress plays a major role in iron overload. Although exercise is a well-established approach to treat/prevent cardiovascular diseases, its effects on iron overload are not known. What is the main finding and its importance? Moderate-intensity aerobic training had benefits in a rodent model of iron-overload cardiomyopathy by improving the antioxidant capacity of the heart. After further confirmation by translational and clinical studies, we should consider using this non-pharmacological, highly accessible and easily executable adjuvant approach allied to other therapies to improve the quality of life of iron-overloaded patients. Iron is an essential micronutrient for several life processes, but its excess can damage organs owing to oxidative stress, with cardiomyopathy being the leading cause of death in iron-overloaded patients. Although exercise has long been considered as a cardioprotective tool, its effects on iron overload are not known. This study was designed to investigate the effects of moderate-intensity aerobic training in rats previously submitted to chronic iron overload. Wistar rats received i.p. injections of iron dextran (100mg/kg, 5days/week for 4weeks); thereafter, the rats were kept sedentary or exercised (60min/day, progressive aerobic training, 60-70% of maximal speed, 5days/week on a treadmill) for 8weeks. At the end of the experimental period, haemodynamics were recorded and blood samples, livers and hearts harvested. Myocardial mechanics of papillary muscles were assessed in vitro, and cardiac remodelling was evaluated by histology and immunoblotting. Iron overload led to liver iron deposition, liver fibrosis and increased serum alanine aminotransferase and aspartate aminotransferase. Moreover, cardiac iron accumulation was accompanied by impaired myocardial mechanics, increased cardiac collagen typeI and lipid peroxidation (TBARS), and release of creatine phosphokinase-MB to the serum. Although exercise did not influence iron levels, tissue injury markers were significantly reduced. Likewise, myocardial contractility and inotropic responsiveness were improved in exercised rats, in association with an increase in the endogenous antioxidant enzyme catalase. In conclusion, moderate-intensity aerobic exercise was associated with attenuated oxidative stress and cardiac damage in a rodent model of iron overload, thereby suggesting its potential role as a non-pharmacological adjuvant therapy for iron-overload cardiomyopathy.

The Effect of Six Weeks of Moderate-Intensity Endurance Training on Serum Levels of Klotho and Expression of the Fibroblast-23 Growth Factor Gene (FGF23) in the Hearts of Diabetic Rats: An Experimental Study

The Effect of Six Weeks of Moderate-Intensity Endurance Training on Serum Levels of Klotho and Expression of the Fibroblast-23 Growth Factor Gene (FGF23) in the Hearts of Diabetic Rats: An Experimental Study

Effects of Moderate-Intensity Intermittent Circuit Training in Obese and Overweight Individuals

Obesity has become a serious problem in Western societies and is associated with several health problems and reduced quality of life. The purpose of this randomised, clinical trial is to investigate the effects of a moderate-intensity, intermittent, circuit training program on a range of cardiovascular risk factors such as body composition, biochemical and physiological variables and aerobic capacity in obese and overweight individuals.

Effects of Six-Week Endurance Training in Liver Enzymes, Lipid Profile, Interleukin-6 and High-Sensitivity C-Reactive Protein (hs-CRP) Responses in People with a Family History of Coronary Artery Disease

Background: Research on the effects of moderate-intensity endurance training on inflammatory indices and cardiovascular risk factors is limited. Objectives: The aim of this study was to determine the effects of six weeks of endurance training on liver enzymes, body composition, lipid profile, interleukin-6, and C-reactive protein responses in people with a family history of coronary artery disease (CAD). Methods: Thirty men (30 - 45years) participated in this study who were divided into two groups, including the control group (n = 10) and training group (n = 20) systematically. The training group program consisted of running on a treadmill for 30 minutes with an intensity of 55 to 60% of maximum heart rate. These training programs were continued three times a week for six weeks. The control group did not perform any exercise program. ELISA technique was used to measure lipid profile, liver enzymes, interlukin-6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP), respectively. Results: The results showed that the variables of weight, liver enzymes, lipid profile, IL-6, and hs-CRP were significantly different from the pre-test (P &lt; 0.05). Also, in between-group comparison, the results showed that except for the variables of fat percentage and BMI in the other variables of the study, a significant difference was observed (P &lt; 0.05). Conclusions: The results of this study suggest that moderate-intensity endurance training could be used as a useful way to reduce weight, levels of inflammatory markers, liver enzymes and cardiovascular risk factors in people with a family history of CAD.

The effect of acute aerobic exercise on the consolidation of motor memories.

Acute aerobic exercise performed prior to training may assist with motor skill acquisition through enhancement of motor cortical plasticity. In addition, high-intensity exercise performed after training improves retention, although the mechanisms of this are unclear. We hypothesized that acute continuous moderate-intensity exercise performed post-motor training would also assist with motor skill retention and that this behavioral change would be positively correlated with neural markers of training-related cortical adaptation. Participants [n = 33; assigned to an exercise (EXE) or control (CON) group] completed a single visuomotor training session using bilateral wrist movements while movement-related cortical potentials (MRCPs) were collected. After motor training, the EXE group exercised for 20min [70% of heart rate reserve (HRR)] and the CON group read for the same amount of time. Both groups completed two post-training tests after exercise/rest: 10min and ~ 30min once heart rate returned to resting level in EXE. Retention and transfer tests were both completed 1 and 7days later. MRCPs measured training-related neural adaptations during the first visit and motor performance was assessed as time and trajectory to the target. The EXE group had better performance than CON at retention (significant 7days post-training). MRCP amplitudes increased from early to late motor training and this amplitude change was correlated with motor performance at retention. Results suggest that moderate-intensity exercise post-motor training helps motor skill retention and that there may be a relationship with motor training-related cortical adaptations that is enhanced with post-motor training exercise.

Few Structural Brain Changes Associated With Moderate-Intensity Interval Training and Low-Intensity Continuous Training in a Randomized Trial of Fitness and Older Adults.

This study utilized a randomized control trial to examine whether structural changes in the precuneus, insula, caudate, hippocampus, and putamen were related to exercise. A total of 197 healthy older adults with no evidence of dementia participated in moderate-intensity interval training or low-intensity continuous training for 16 weeks. Size decreased in the right hippocampus such that the effect of time was significant but the interaction with condition was not. For the left hippocampus, size decreased in the low-intensity continuous training condition but increased in the moderate-intensity continuous training plus interval training condition at the trend level. Finally, there was a significant time-by-condition interaction such that the thickness of the left insula increased for low-intensity continuous training and decreased for moderate-intensity continuous training plus interval training. Few structural changes were associated with the exercise intervention. Future studies should examine the effects of exercise on brain structure in high-risk or clinical populations for a longer period of time.

PROGRAMAS DE EJERCICIO FÍSICO EN PERSONAS CON ENFERMEDAD DE LAS ARTERIAS CORONARIAS

The aim of this study was to know the influence of physical exercise programs (PEP) and their prescription characteristics on variables of cardiac rehabilitation in people with coronary artery disease (CAD). We conducted a review of systematic reviews and meta-analyzes, with articles published up to September 1, 2019. A total of 3902 articles were identified, of which 4 were selected. The studies presented a moderate and high quality. Evidence was found on the best ranges of the duration of high intensity interval training, and of the frequency, duration, intensity and session time of continuous moderate intensity training. More studies are needed to reach consistent conclusions about the characteristics of these and other PEP.

Task-Oriented Circuit Training as an Alternative to Ergometer-Type Aerobic Exercise Training after Stroke.

Moderate-intensity aerobic exercise training is an important treatment strategy to enhance functional recovery and decrease cardiometabolic risk factors after stroke. However, stroke related impairments limit access to ergometer-type exercise. The aims of the current study were (1) to evaluate whether our task-oriented circuit training protocol (intermittent functional training; IFT) could be used to sustain moderate-intensity aerobic workloads over a 10-week intervention period, and (2) to investigate its preliminary effects on cardiorespiratory fitness and metabolic profiles compared to constant-load ergometer-type exercise (CET). Forty chronic hemiparetic stroke survivors were randomized to receive 30 sessions of IFT or CET over ten weeks. Similar proportions of participants were randomized to IFT (7/19) and CET (9/18) sustained workloads associated with moderate-intensity aerobic exercise over the study period (p = 0.515). However, CET was associated with more substantial changes in maximal oxygen uptake (MD = 2.79 mL min−1 kg−1 CI: 0.84 to 4.74) compared to IFT (MD = 0.62 mL min−1 kg−1 CI: −0.38 to 1.62). Pre to post changes in C-reactive protein (−0.9 mg/L; p =0.017), short-term glycemia (+14.7 µmol/L; p = 0.026), and resting whole-body carbohydrate oxidation (+24.2 mg min−1; p = 0.046) were observed when considering both groups together. Accordingly, IFT can replicate the aerobic intensities sustained during traditional ergometer-type exercise training. More work is needed to evaluate the dose–response effects of such task-oriented circuit training protocols on secondary prevention targets across the continuum of stroke recovery.

Potential role of Nigella sativa supplementation with physical activity in prophylaxis and treatment of COVID-19: a contemporary review

The widespread prevalence and mortality of coronavirus diseases-2019 (COVID-19) lead many researchers to study the SARS-CoV-s2 infection to find a treatment for this disease. Discovering the mechanisms of action of COVID-19 and coping at the cellular level with this disease can have better effects. Including the target tissues of this disease are the lungs and the immune system. It is stated that COVID-19 easily infiltrates into alveoli through its receptors and then starts to proliferate. Subsequently, with the weakening of immune cells and increase inflammatory cytokines, it increases the rate of inflammation in the body. Strengthening the immune system and inhibiting COVID-19 receptors can play a preventive or even therapeutic role for this disease. Nigella sativa (N. sativa) is one of the herbal medicines to possess numerous pharmacological effects related to several organs of the body. Among the extraordinary properties of this plant is improving asthma and several lung diseases. The recent studies have shown that N. sativa at the cellular level can inhibit COVID-19 receptors. It was also stated that performing regular exercise training (especially moderate-intensity exercise training) can modulate the immune system and have an anti-inflammatory effect. Since the use of herbal supplements with exercise can have tremendous therapeutic effects at the cellular level, the hypothesis to use the Nigella sativa along with exercise training to prophylaxis and treatment COVID-19 will be highlighted in this paper.

Traditional Lègong Dance Training Is Superior to Moderate Aerobic Training on Physical Fitness Improvement Among Young Girls.

Légong dance is a famous Balinese dance with a dynamic movement. It potentially becomes an exercise of choice to improve young girls' physical fitness. This study aimed to evaluate légong dance training's effect on physical fitness compared with aerobic training. Forty young girls were randomly assigned to the aerobic training (AG) and lègong dance (DG) group and trained with jogging and lègong dancing at moderate-intensity aerobic training. Each was carried out for 30minutes, 3 times a week, for 6 weeks. Aerobic capacity (estimated maximal oxygen consumption) improved significantly in AG and DG, with a mean difference and Cohen d effect size of 0.36mL/kg/min and 0.68. The back- and leg-muscle strength increased significantly in DG and AG, with a mean difference of 5.55kg and 6.67kg, and an effect size of 0.69 and 0.77. Balance improved significantly in DG and AG, with a mean difference of 21.26 seconds and an effect size of 1.05. All significant values are reported at P < .05. There were no significant improvements in arm muscle strength, body fat percentage, and flexibility in either group (P > .05). Lègong dance training results in significant physical fitness improvement and better results than aerobic training.

Rationale and design of remotely-supervised cardiac rehabilitation study in patients with obstructive sleep apnea

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Ministry of Health Czech Republic; identification of organization 65269705 Background Although continuous positive airway pressure (CPAP) is currently still the gold standard for therapy of moderate to severe obstructive sleep apnea (OSA), another alternative or adjunct effective therapeutic options exist. Lifestyle intervention focused on nutrition and weight reduction, regular exercise, sleep hygiene, smoking and alcohol restriction represents a recommended therapeutic strategy for OSA. Though this intervention represents an effective tool for improving objective and subjective parameters of OSA, it’s effectivity depends on components of the intervention, OSA severity and gender. Comprehensive remotely-supervised cardiac rehabilitation (CR) represents possible training intervention in home conditions using elements of telemedicine. Purpose This prospective study aims to investigate the feasibility and effect of a remotely-supervised CR in patients with newly diagnosed OSA with Apnea-Hypopnea Index greater than 15 episodes per hour. Methods This monocentric study is designed as a prospective, parallel, randomised, controlled trial of remotely-supervised 12-week CR in male patients between 40-60 years old with newly diagnosed OSA indicated to CPAP therapy. The sample size is calculated by 0,05 level of significance and 80% statistical power on 25 participants in each group. The Intervention group will undergo comprehensive remotely-supervised CR in home conditions with teleconsultation (contains telecoaching, telemonitoring) via regular phone calls and e-mails at least 1-2 times a week. The intervention will include nutrition, health-related lifestyle and behavioral changes recommendations, and at least 5 times a week 30 minutes of moderate-intensity aerobic training, 10 minutes of inspiratory and expiratory muscle training with breathing device and 10 minutes of oropharyngeal exercise along with individually titrated CPAP therapy. The control group will undergo individually titrated CPAP therapy only. The participants in both groups will go through the following assessments before and after this study: polysomnography, spirometry, anthropometry and body composition examination, laboratory values examination, quality of life questionnaires, Epworth sleepiness scale, 6-min walking test. Conclusions: Comprehensive remotely-supervised CR, as mentioned in this study, may represent an adjunct therapy with a promising future in patients with OSA. The study is occupied with a current issue and can also bring new possibilities and experiences in remote rehabilitation.

Effect of exercise training on amyloid-like protein aggregates among patients with heart failure

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): MG and CS were supported by a PhD FCT grant (SFRH/BD/128893/2017) and by an individual grant from CAPES [BEX 0554/14-6], respectively. This work was financially supported by the project POCI-01-0145-FEDER-030011, funded by FEDER, through COMPETE2020-POCI, and by national funds, through FCT/MCTES (PTDC/MEC-CAR/30011/2017). iBiMED is a research unit supported by the Portuguese Foundation for Science and Technology (REF: UID/BIM/04501/2020) and FEDER/Compete2020 funds). Introduction Amyloid-like protein aggregates play a decisive role in the pathology of heart failure. Alterations in protein homeostasis, in particular, the clearance of toxic amyloid-like aggregates are emerging therapeutic targets in cardiovascular medicine. The clinical benefits of cardiac rehabilitation and exercise training are widely accepted in heart failure; however, little is known about the potential benefit of exercise training in amyloid-like protein aggregates. Purpose To assess the effects of a moderate-intensity exercise training program on amyloid-like protein aggregates levels among patients with heart failure with reduced ejection fraction. Methods Eighteen subjects participated in the study; eight patients (age: 66.6 ± 5.9 years; FEVE: 38.4 ± 8.9%) with heart failure with reduced ejection fraction participated in a 3-month exercise training program (2 x 60 min sessions per week of moderate-intensity aerobic and resistance exercise). Ten healthy subjects (age: 68. 4 ± 3.1 years) were recruited to an age-matched reference group. Amyloid-like protein aggregates were assessed before and after 3 months of exercise training. Clinical data, medication, anthropometrics, and cardiorespiratory fitness were also assessed. Thioflavin T (ThT) dye fluorescence was used to quantify the plasma levels of amyloid-like aggregates and the Fourier transform infrared spectroscopy (FTIR) was applied to evaluate the conformation of cross-β-sheet structures characteristic of amyloid protein aggregates. Results Exercise program improved cardiorespiratory fitness by 14.0 ± 17.1% (17.4 ± 3.2 to 19.7 ± 2.9 ml/kg/min) and reduced NT-proBNP levels by 16.5% (34.2) (median concentration of 632 pg/mL (720.8) to 517.5 pg/mL (707.0)) in the heart failure patients. A slight decrease of amyloid-like aggregates levels was observed in post-exercise training samples (a reduction of 3.1%); interestingly, after the exercise training program, the heart failure patients showed levels of amyloid-like aggregates similar to the reference group (1132.0 ± 114.2 vs. 1094.8 ± 132.9 a.u.). Additionally, the PLS-R multivariate analysis of the amide I region of the FTIR spectra revealed enrichment of antiparallel β-sheets (1693 cm-1) assigned to amyloid-like oligomers in the samples of heart failure patients before, but not after, the exercise program. Of note, oligomeric species, as intermediates of amyloid assembly, can contribute to the increase of amyloid burden, but also, some have been reported to be highly reactive and toxic to cells, being key elements of amyloid pathogenesis. Conclusions Our preliminary results indicate that 3 months of exercise training may have significant effects on amyloid-like oligomers, and start hindering the formation of the larger ThT-positive aggregates among patients with heart failure. Abstract Figure.

Presence and clinical significance of myocardial ischemia during aerobic exercise training in patients with ischemic burden

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiovascular rehabilitation is efficient and safe for patients with coronary artery disease (CAD). Exercises are usually prescribed below the clinic and electrocardiographic ischemic threshold. Training above this threshold remains controversial, given the potential risks compared to the additional benefits. However, clinic and electrocardiographic detection of ischemia has lower accuracy than myocardial perfusion scintigraphy (MPS). Therefore, MPS during physical training can better assess ischemia. Moreover, serial maximum MPS can document the benefits of exercise that can be correlated with ischemia during training. Purpose To investigate the presence and clinical significance of scintigraphic myocardial ischemia during aerobic exercise in patients with CAD and ischemic burden. Methods Thirty-three patients with stable CAD were evaluated at maximum effort (M1) and at rest (R1) using MPS. Twelve patients were excluded; 3 did not complete the intervention, and 9 did not exhibit ischemia. The remaining 21 patients with ischemic burden were included. The intervention consisted of a 12-week training program of moderate-intensity aerobic exercises, below the clinical and electrocardiographic ischemic threshold. During weeks 1 (T1) and 12 (T2), patients underwent MPS during the exercises. After 12 weeks, patients underwent another MPS at maximum effort (M2). All images were quantitatively analyzed, and the presence, extent, and intensity of ischemia were determined. The Wilcoxon test was used to compare 2 variables, and the Friedman test to compare 3 variables, followed by the post hoc Dunn’s test. Correlations were analyzed using Spearman’s test. The level of significance was set at 5% (p &amp;lt; 0.05). Results The prevalence of scintigraphic ischemia during exercise training was 81% at T1 and 71% at T2. The median number (and interquartile range) of ischemic segments at T1 was 3 (2–5), which was significantly different (p = 0.003) from that observed at M1 [5 (3–8)]. The median values of the myocardial uptake in the ischemic segments at R1, T1, and M1 were 59.1% (53.1–68.5), 51.5% (45.3–60.3), and 40.8% (37.3–53.3), respectively, with significant differences between T1 and R1 (p &amp;lt; 0.05) and between T1 and M1 (p &amp;lt; 0.01). After 12 weeks, the extent and intensity of ischemia at maximum effort decreased. The median number of ischemic segments significantly decreased from 5 (3–8) at M1 to 4 (2–6) at M2 (p = 0.005). This reduction in the extent of ischemia after training was significantly correlated with the number of ischemic segments at M1 (r = 0.60; p = 0.004) and at T1 (r = 0.64; p = 0.002), such that patients with more extensive ischemia experienced greater benefits from training. Conclusions Scintigraphic ischemia was highly prevalent during moderate-intensity aerobic training in patients with CAD and ischemic burden. There was a correlation between the ischemic stimulus during training and the documented benefits at maximum effort. Abstract Figure. Polar maps at rest, training and maximum

Impact of interval training with probiotic (L. plantarum / Bifidobacterium bifidum) on passive avoidance test, ChAT and BDNF in the hippocampus of rats with Alzheimer’s disease

It has been suggested that gut microbiota dysbiosis can lead to Alzheimer’s disease (AD), inducing the production of many AD-related pre-inflammatory cytokines. On the other hand, daily probiotic administration and regular exercise training are assumed to improve clinical AD-related symptoms. To take this line of research further, this study was aimed at investigating the impact of moderate-intensity interval training (MIIT) with a combined administration of Lactobacillus plantarum and Bifidobacterium bifidum (probiotic, BROB) on the passive avoidance test (Shuttle Box), choline acetyltransferase (ChAT) and the brain derived neurotrophic factor (BDNF) in the hippocampus of a rat model of AD. Forty male Wistar rats (280 ± 20 g) were divided into five groups (n = 8 in each) of control, amyloid beta peptide (Aβ), Aβ + MIIT (AD rats undergoing MIIT), Aβ + PROB (AD rats fed Lactobacillus plantarum and Bifidobacterium bifidum), and Aβ + MIIT + PROB (AD rats receiving both treatments). AD was induced by the intra-cerebroventricular injection of Aβ1-42 peptide. MIIT was performed on rodent treadmill for 8 weeks (5 days per week). The probiotic was also fed daily to the related groups for 8 weeks. BDNF and ChAT in the hippocampus were measured by real time PCR (RT-PCR) and immunohistochemistry (IHC), respectively. Cresyl violet staining of brain tissue was performed to evaluate the dead cells. Results of tissue staining showed that the induction of the Alzheimer’s led to the destruction of hippocampal cells and induced neurodegeneration (p = 0.001). Results of the shuttle box test showed that short-term memory was improved in the Aβ + MIIT + PROB group compared to the Aβ group, while death cells (dark cells) were decreased in all the other three groups (MIIT, BROB, and Aβ + MIIT + PROB). Levels of ChAT as well as the BDNF mRNA in the Aβ + MIIT + PROB group showed a significant increase compared to the Aβ group. In conclusion, it seems that the use of the combined administration of Lactobacillus plantarum and Bifidobacterium bifidum with interval aerobic exercise can have neuroprotective effects on AD.

Effect of Moderate and High Intensity Exercise on Hypoxia and Radiosensitivity in Tumor‐Bearing Rats

Background Prostate tumors typically have hypoxic regions that are resistant to traditional radiation therapy. Prior evidence from our laboratory has demonstrated improved perfusion and reduced hypoxia of prostate tumors with moderate intensity exercise training; such changes have potential to enhance radiation therapy. However, there is a dearth of evidence for the magnitude of alterations of intra-tumor hypoxia markers with exercise, as well as the ideal intensity of exercise for combating hypoxia in solid tumors. Using a pre-clinical orthotopic model of prostate cancer, we tested the hypothesis that exercise training at both moderate and high intensities would result in a decrease in hypoxia assessed via immunohistochemical analysis of hypoxic markers. Further, that enhanced radiotherapy responses would occur in exercise trained tumor bearing animals compared to sedentary counterparts. Methods Immunocompetent male Copenhagen rats aged 6 months (n=48) were injected orthotopically (ventral lobe of prostate) with 1x105 Dunning R-3327 AT-1 prostate adenocarcinoma cells. All animals were first acclimated to treadmill exercise and randomized into three groups: tumor bearing sedentary (TBS, n=20), moderate intensity training, (TBMIT, n=12), or high intensity training (TBHIT, n=16). After 7 days of recovery from surgery, both exercise groups began progressive exercise training on a motorized treadmill at either 20/min with a 5% incline, or 30m/min 15% incline for 10 minutes a day progressing to 60 min/day for TBMIT and TBHIT, respectively, for approximately 5 weeks. Immunohistochemical analysis and whole-body ionizing radiation (2 Gy) were performed at the end of the 5-week period of training followed by clonogenic cell survival assay to assess survival fraction. Results There were no significant differences (p>0.05) in tumor mass between groups (TBS 7.8±1.1; TBMIT 7.2±1.3; TBHIT 6.4±0.9 g). Overall expression levels of hypoxia inducible factor 1-alpha (HIF-1a, n=40) were significantly greater in the TBS group vs both the TBMIT and TBHIT (TBS 37.9±7.4; TBMIT 25.5±6.1; TBHIT 14.4±5.7%, p<0.05), with a trend for increased expression in TBMIT vs TBHIT (p=0.059). The survival fraction (n=8) was also significantly higher in TBS when compared to both TBMIT and TBHIT (TBS 39.9±5.3; TBMIT 23.2±3.2; TBHIT 20.7±4.9%, p<0.05). Conclusion This study suggests that compared to sedentary counterparts, both chronic moderate and high intensity exercise training modify the tumor microenvironment (decreased levels of HIF-1a) favorably. Given exercise therapy is becoming increasingly recommended to mitigate fatigue and increase quality of life in patients, a potential therapeutic component could add to the efficacy of exercise prescription in a clinical setting.

The Effect of High- and Moderate-intensity Endurance Training on Some Anabolic/Catabolic Osteokines in Old Male Wistar Rats

Background: Bone-related osteokines are crucial for bone function and metabolic response to physical activity. The present study aimed to shed light on the effect of different intensities of continuous and interval endurance training on the serum levels of some osteokines that are associated with wingless-related integration site (WNT) signaling pathway and Receptor Activator of Nuclear Factor (NF)-κB Ligand (RANKL) in old male Wistar rats. Materials and Methods: A total of 24 old male Wistar rats (mean age: 23 months, mean weight: 437.93 g) were randomly assigned to three groups: interval endurance-training group (n=8), continuous endurance-training group (n=8), and control group (n=8). The continuous and interval training interventions comprised 8 weeks of treadmill exercise, 5 days a week. The continuous endurance-training group started to exercise at 60% of velocity at maximal oxygen uptake (vVO2max) for 16 min during the first week. It continued with 70% of vVO2max for 45 min from the fourth week onward. In contrast, the interval endurance-training group switched on exercise with 40%-80% of vVO2max from the first week and persisted with 30%-110% of vVO2max from the fourth week onward. As the exercise bout was completed, the enzyme-linked immunosorbent assay was applied to measure the study dependent variables. Statistical analysis was further performed using 1-way analysis of variance, considering the significance level of P≤0.05. Results: The study results demonstrated a significant difference in the levels of Oteoprotegerin (OPG) (P=0.036) and RANKL (P=0.001) in the experimental (namely, interval and continuous training) groups compared with the controls following the exercise bout. However, the level of sclerostin was not significantly changed (P=0.549). Conclusion: High-intensity endurance training in the RANKL/OPG and WNT pathways decreased sclerostin and RANKL levels, but this decrease was significant at the RANKL level. It was effective with regard to the intensities of different types of endurance exercise.

Regulation of circulating CTRP-2/CTRP-9 and GDF-8/GDF-15 by intralipids and insulin in healthy control and polycystic ovary syndrome women following chronic exercise training

BackgroundPolycystic ovary syndrome (PCOS) is associated with obesity, diabetes, and insulin resistance. The circulating C1Q/TNF-related proteins (CTRP-2, CTRP-9) and growth differentiation factors (GDF-8, GDF-15) contribute to glucose and lipid homeostasis. The effects of intralipids and insulin infusion on CTRP-2, CTRP-9, GDF-8 and GDF-15 in PCOS and control subjects before and after chronic exercise training were examined.MethodsTen PCOS and nine healthy subjects were studied at baseline status and after moderate-intensity chronic exercise training (1 h exercise, 3 times per week, 8 weeks). All participants were infused with 1.5 mL/min of saline or intralipids (20%) for 5 h, and during the last 2 h of saline or intralipids infusion hyperinsulinemic-euglycemic clamp (HIEC) was performed. CTRP-2, CTRP-9, GDF-8 and GDF-15 levels were measured at 0, 3 and 5 h.ResultsIntralipids dramatically increased CTRP-2 levels in PCOS (P = 0.02) and control (P = 0.004) subjects, which was not affected by insulin infusion or by exercise. Intralipids alone had no effects on CTRP-9, GDF-8, or GDF-15. Insulin increased the levels of GDF-15 in control subjects (P = 0.05) during the saline study and in PCOS subjects (P = 0.04) during the intralipid infusion. Insulin suppressed CTRP9 levels during the intralipid study in both PCOS (P = 0.04) and control (P = 0.01) subjects. Exercise significantly reduced fasting GDF-8 levels in PCOS (P = 0.03) and control (P = 0.04) subjects; however, intralipids infusion after chronic exercise training increased GDF-8 levels in both PCOS (P = 0.003) and control (P = 0.05) subjects and insulin infusion during intralipid infusion reduced the rise of GDF-8 levels.ConclusionThis study showed that exogenous lipids modulate CTRP-2, which might have a physiological role in lipid metabolism. Since chronic exercise training reduced fasting GDF-8 levels; GDF-8 might have a role in humoral adaptation to exercise. GDF-15 and CTRP-9 levels are responsive to insulin, and thus they may play a role in insulin responses.

High Intensity Training Increases Muscle Area Occupied by Type II Muscle Fibers of the Multifidus Muscle in Persons with Non-Specific Chronic Low Back Pain: A Pilot Trial

Low back pain is a prevalent musculoskeletal disorder with high disability. Although exercise therapy is an important part of the multidisciplinary treatment of non-specific chronic low back pain (NSCLBP), the impact of exercise therapy on muscle morphology of the paraspinal muscles is largely unknown. The main aim of this study is to evaluate the effects of a high intensity training (HIT) program on muscle fiber characteristics of the multifidus (MF) and the erector spinae (ES) musculature in persons with NSCLBP and to compare these results with the effects of a moderate intensity training (MIT) program, which is used as a control group. In total, 38 participants with NSCLBP were randomly assigned to a HIT or MIT intervention group. Participants performed a 12-week training program. At baseline and after the training program, biopsy samples from the lumbar MF and ES were obtained. Muscle fiber characteristics were analyzed by immunofluorescence. For the ES, no significant changes were found in muscle fiber CSA and distribution of muscle fiber types in response to a training program at moderate or at high intensity. For the MF, a significant higher muscle area occupied by type II muscle fibers, referred to as the relative cross-sectional area (RCSA), was found in the HIT group. Based on muscle fiber characteristics in biopsy samples, a HIT program of 12 weeks seems to result in a more glycolytic profile in the MF.