Low-intensity Exercise Training Research Articles

Low-intensity exercise training improves systolic function of heart during metastatic melanoma-induced cachexia in mice

Cardiac dysfunction frequently emerges in the initial stages of cancer cachexia, posing a significant complication of the disease. Physical fitness is commonly recommended in these early stages of cancer cachexia due to its beneficial impacts on various aspects of the condition, including cardiac dysfunction. However, the direct functional impacts of exercise on the heart during cancer cachexia largely remain unexplored. In this study, we induced cancer cachexia in mice using a metastatic B16F10 melanoma model. Concurrently, these mice underwent a low-intensity exercise regimen to investigate its potential role in cardiac function during cachexia. Our findings indicate that exercise training can help prevent metastatic melanoma-induced muscle loss without significant alterations to body and fat weight. Moreover, exercise improved the melanoma-induced decline in left ventricular ejection fraction and fractional shortening, while also mitigating the increase in high-sensitive cardiac troponin T levels caused by metastatic melanoma in mice. Transcriptome analysis revealed that exercise significantly reversed the transcriptional alterations in the heart induced by melanoma, which were primarily enriched in pathways related to heart contraction. These results suggest that exercise can improve systolic heart function and directly influence the transcriptome of the heart during metastatic melanoma-induced cachexia.

Low-intensity exercise training increases systolic function of heart and MHCII low cardiac resident macrophages

Physical activities have beneficial effects on cardiovascular health, although the specific mechanisms are largely unknown. Cardiac resident macrophages (cMacs) and the distribution of their subsets are critical regulators for maintaining cardiovascular health and cardiac functions in both steady and inflammatory states. Therefore, we investigated the subsets of cMacs in mice after low-intensity exercise training to elucidate the exercise-induced dynamic changes of cMacs and the benefits of exercise for the heart. The mice were subjected to treadmill running exercise five days per week for five weeks using a low-intensity exercise training protocol. Low-intensity exercise training resulted in a suppression of body weight gain in mice and a significant increase in the ejection fraction, a parameter that represents the systolic function of the heart. Low-intensity exercise training induced the alterations in the transcriptome of the heart, which are associated with muscle contraction and mitochondrial function. Furthermore, low-intensity exercise training did not alter the number of lymphocyte antigen 6 complex, locus C1 (Ly6c)− cMacs but instead remodeled the distributions of Ly6c− cMac subsets. We observed an increase in the percentage of major histocompatibility complex class II (MHCII)low cMacs and a decrease in the percentage of MHCIIhigh cMacs in the heart after low-intensity exercise training. Therefore, the benefits of exercise for cardiovascular fitness might be associated with the redistribution of cMac subsets and the enhancement of the ejection fraction.

Influences of high vs. low-intensity exercises on muscle strength, function, and quality of life in post-COVID-19 patients with sarcopenia: a randomized controlled trial.

The aim of this study was to compare the effectiveness of high vs. low-intensity exercise training on muscle strength, physical function, and quality of life in post-COVID-19 patients with sarcopenia secondary to chronic kidney disease (CKD). 82 subjects were randomized into 2 groups: high intensity (HIG, n=42), which received high-intensity resistance training, and low intensity (LIG, n=40), which conducted low-intensity aerobic activities. Exercises were performed for 30 min, 3 times per week for 6 weeks. A handheld dynamometer, pinch press, and 1 min sit-to-stand (STS) test were used to assess muscle strength. Modified physical performance test and sarcopenia Quality of Life questionnaire (SAR-QoL) were used to assess function and quality of life, respectively. Measures were collected before and at the end of the treatment program. Participants were similar at baseline. The within-group comparisons demonstrated statistically significant improvement in both HIG and LIG groups in all outcome measures (p<0.001). Between groups, comparisons revealed statistically significant better achievements with high effect size in Modified Physical Performance Test (MMPT) (p<0.001, d=1.28), handgrip (p<0.001, d=3.6), STS (p<0.001, d=2.38), and SAR-QoL (p<0.001, d=3.24) in favor of the HIG. On the other hand, pinch press strength was equally improved in both groups (p=0.09, d=0.36). High-intensity exercise is better than low-intensity exercises in post-COVID-19 patients with sarcopenia secondary to chronic kidney disease regarding muscle strength, physical function, and quality of life.

Amenorrhea and oligomenorrhea risk related to exercise training volume and intensity: Findings from 3705 participants recruited via the STRAVA™ exercise application.

To investigate associations between self-reported exercise training habits and amenorrhea/oligomenorrhea among physically active women. A cross-sectional survey was completed by 3705 women (median age = 40 years [quartile 1, quartile 3: 30, 45], body mass index = 22.1 kg/m2 [20.5, 24.2]) representing multiple nationalities and sports via the STRAVA™ exercise application. Respondents selected the amount of time they participated in low intensity, moderate intensity, and high intensity exercise training per week. Amenorrhea/oligomenorrhea was defined as self-reporting ≤10 menses in the last year. Associations between weekly exercise volume for low intensity training, moderate intensity training, and high intensity training and amenorrhea/oligomenorrhea were modeled with univariate logistic regression models, followed by adjustment for age and body mass index. Amenorrhea/oligomenorrhea prevalence was 16 % (n = 576/3705), with no difference by country of origin or most sport modes. In adjusted models, participating in low intensity training ≥7 h/week or moderate intensity training ≥6 h/week was associated with 1.43 (95 % confidence interval: 1.04-1.96) and 1.46 (1.10-1.95) greater odds of amenorrhea/oligomenorrhea compared to 2 to 3 h/week, respectively. Similarly, high intensity training ≥5 h/week was associated with 1.41 (1.03-1.92) greater odds of amenorrhea/oligomenorrhea compared to 1 to 2 h/week. Participating in low intensity training for ≤30 min/week compared to 2 to 3 h/week was associated with reduced amenorrhea/oligomenorrhea odds (0.65 [0.44-0.94]). Taken together, these associations suggest greater weekly exercise volume, irrespective of intensity, may increase amenorrhea/oligomenorrhea risk among physically active women.

Safety and effectiveness of standardized exercise training in patients with pulmonary hypertension associated with heart failure with preserved ejection fraction (TRAIN-HFpEF-PH): study protocol for a randomized controlled multicenter trial

BackgroundLeft heart failure (HF) is characterized by an elevation in left-sided filling pressures, causing symptoms of dyspnea, impairing exercise capacity, and leading to pulmonary venous congestion and secondary pulmonary hypertension (PH). There is an increased incidence of PH associated with left heart disease, particularly with heart failure with preserved ejection fraction (HFpEF-PH). Treatment possibilities in HFpEF-PH are non-specific and very limited, thus additional pharmacological and non-pharmacological therapeutic strategies are needed. Various types of exercise-based rehabilitation programs have been shown to improve exercise capacity and quality of life (QoL) of HF and PH patients. However, no study focused on exercise training in the population of HFpEF-PH. This study is designed to investigate whether a standardized low-intensity exercise and respiratory training program is safe and may improve exercise capacity, QoL, hemodynamics, diastolic function, and biomarkers in patients with HFpEF-PH.MethodsA total of 90 stable patients with HFpEF-PH (World Health Organization functional class II–IV) will be randomized (1:1) to receive a 15-week specialized low-intensity rehabilitation program, including exercise and respiratory therapy and mental gait training, with an in-hospital start, or standard care alone. The primary endpoint of the study is a change in 6-min walk test distance; secondary endpoints are changes in peak exercise oxygen uptake, QoL, echocardiographic parameters, prognostic biomarkers, and safety parameters.DiscussionTo date, no study has investigated the safety and efficacy of exercising specifically in the HFpEF-PH population. We believe that a randomized controlled multicenter trial, which protocol we are sharing in this article, will add important knowledge about the potential utility of a specialized low-intensity exercise and respiratory training program for HFpEF-PH and will be valuable in finding optimal treatment strategies for these patients.Trial registrationClinicalTrials.gov NCT05464238. July 19, 2022.

Low intensity exercise training in patients with amyotrophic lateral sclerosis – factors influencing eligibility and compliance to the clinical trial

ABSTRACT Background To date, there are no evidence-based recommendations for physical therapy in amyotrophic lateral sclerosis (ALS). The reason is a low number of related clinical trials (CTs), restricted sample sizes and a high dropout rate. It may influence the profile of the participants, while the final results might not translate to the general ALS population. Objective To analyze factors affecting the ALS patients’ enrollment and retention to the study, and to describe a profile of participants as compared to the eligible group. Methods A total of 104 ALS patients were offered participation in a CT of low-intensity exercises at home. Forty-six patients were recruited. Demographic and clinical data (El Escorial criteria, site of onset, diagnosis delay, disease duration, amyotrophic lateral sclerosis functional rating scale – revised [ALSFRS-R], Medical Research Council [MRC], hand-held dynamometry) were analyzed every 3 months. Results Male gender, younger age and a higher ALSFRS predicted enrollment, while male gender, higher ALSFRS-R and MRC predicted retention in the study. A long commute to the study site and a fast disease progression were the main reasons influencing both enrollment and retention. Despite a high dropout rate, study participants were representative for the general ALS population. Conclusion The above demographic, clinical and logistic factors need to be considered when designing studies in ALS population.

Low-Intensity Exercise Affects Cardiac Fatty Acid Oxidation by Increasing the Nuclear Content of PPARα, FOXO1, and Lipin1 in Fructose-Fed Rats.

Background and Aim: Excessive fructose consumption along with a sedentary lifestyle provokes metabolic disorders and cardiovascular diseases. Fructose overload causes cardiac insulin resistance and increases reliance on fatty acid (FA) uptake and catabolism. The cardiometabolic benefits of exercise training have long been appreciated. The goal of the presented study is to shed a new light to the preventive role of exercise training on cardiac lipid metabolism in fructose-fed rats. Methods: Male Wistar rats were divided into control (C), sedentary fructose (F), and exercised fructose (EF) groups. Fructose was given as a 10% fructose solution in drinking water for 9 weeks. Low-intensity exercise training was applied for 9 weeks. The protein expression and subcellular localization of Lipin1, peroxisome proliferator-activated receptor α (PPARα), and peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC1) were analyzed in the heart using Western blot. Cardiac forkhead box transcription factor 1 (FOXO1) and sirtuin 1 (SIRT1) protein levels were also evaluated. Gene expression of long-chain acyl-CoA dehydrogenase was analyzed by quantitative polymerase chain reaction. Results: Exercise training has augmented the expression of main regulators of FA oxidation in the heart and achieves its effect by increasing the nuclear content of PPARα, Lipin1, and FOXO1 compared with the fructose group (P = 0.0422, P = 0.000045, P = 0.00958, respectively). In addition, Lipin1, FOXO1, and SIRT1 were increased in nuclear extract after exercise compared with the control group (P = 0.000043, P = 0.0417, P = 0.0329, respectively). In cardiac lysate, low-intensity exercise caused significantly increased protein level of PPARα, PGC1, FOXO1, and SIRT1 compared with control (P = 0.0377, P = 0.0275, P = 0.0096, P = 0.0282, respectively) and PGC1 level compared with the fructose group (P = 0.0417). Conclusion: The obtained results imply that the heart with a metabolic burden additionally relies on FA as an energy substrate after low-intensity running.

Inhibition of Rho/ROCK signaling pathway participates in the cardiac protection of exercise training in spontaneously hypertensive rats

Exercise training (ExT) is capable of improving the heart function of spontaneously hypertensive rats (SHRs), but the underlying molecular mechanisms remain elusive. This study was aimed to investigate whether inhibition of RhoA/ROCK signaling pathway contributes to the cardiac protection by low-intensity ExT in SHRs. The results demonstrated that, compared with Wistar-Kyoto (WKY) rats, SHRs obviously exhibited higher blood pressure, increased heart weight index and thickness of left ventricular wall, decreased left ventricular function, damaged myocardial construction, and increased collagen fiber of left ventricle (P < 0.05 or P < 0.01). Meanwhile, the mRNA and protein expression levels of RhoA and ROCK in the heart of SHRs were significantly increased, compared with those of WKY rats (P < 0.05 or P < 0.01). Interestingly, the pathological changes of heart aforementioned were all improved in SHR-ExT rats compared with SHR-Sed rats (P < 0.05 or P < 0.01), indicating the cardiac protection of exercise training. In addition, the cardiac protective effect of exercise training could be blocked by LPA, an activator of Rho/ROCK signaling, and the protective effect in SHR rats could be mimicked by Fasudil, an inhibitor of Rho/ROCK signaling. The results strongly suggest that low-intensity ExT can protect heart against structure and function through inhibiting Rho/ROCK signaling pathway in hypertensive rats.

Safety and Efficacy of a Bodyweight Exercise Training Program in Symptomatic Patients With Severe Aortic Valve Stenosis

Conventional exercise therapy including aerobic and resistance training is desirable for cardiovascular disease, whereas it is generally considered contraindicated for symptomatic severe aortic valve stenosis (AS). This study aimed to evaluate the safety and efficacy of bodyweight resistance exercise training (BRET), which is low-intensity exercise training in symptomatic patients with severe AS. A BRET program consisting of 8 exercises was performed 3 times a week by patients with AS with physical therapists. For the 78 symptomatic patients with severe AS, the median aortic valve area and mean transaortic valve pressure gradient were 0.56 cm2 and 48.9 mm Hg, respectively; none showed any harmful changes in blood pressure or heart rate in 11 sessions of the BRET program. There were no adverse events during hospitalization. Meanwhile, Barthel's Index score significantly improved at the time of hospital discharge. In conclusion, the BRET program in this study did not appear to cause harmful changes in hemodynamics during the program or adverse events during hospitalization, and it improved activities of daily living in symptomatic patients with severe AS, allowing doctors and physical therapists to conduct it safely, with less emotional stress, for cardiac rehabilitation for such patients.

Increased contribution of KCa channels to muscle contraction induced vascular and blood flow responses in sedentary and exercise trained ZFDM rats

In resistance arteries, endothelium-dependent hyperpolarization (EDH)-mediated vasodilatation is depressed in diabetes. We hypothesized that downregulation of KCa channel derived EDH reduces exercise-induced vasodilatation and blood flow redistribution in diabetes. To test this hypothesis, we evaluated vascular function in response to hindlimb muscle contraction, and the contribution of KCa channels in anaesthetised ZFDM, metabolic disease rats with type 2 diabetes. We also tested whether exercise training ameliorated the vascular response. Using in vivo microangiography, the hindlimb vasculature was visualized before and after rhythmic muscle contraction (0.5s tetanus every 3s, 20 times) evoked by sciatic nerve stimulation (40Hz). Femoral blood flow of the contracting hindlimb was simultaneously measured by an ultrasonic flowmeter. The contribution of KCa channels was investigated in the presence and absence of apamin and charybdotoxin. We found that vascular and blood flow responses to muscle contraction were significantly impaired at the level of small artery segments in ZFDM fa/fa rats compared to its lean control fa/+ rats. The contribution of KCa channels was also smaller in fa/fa than in fa/+ rats. Low-intensity exercise training for 12weeks in fa/fa rats demonstrated minor changes in the vascular and blood flow response to muscle contraction. However, the KCa-derived component in the response to muscle contraction was much greater in exercise trained than in sedentary fa/fa rats. These data suggest that exercise training increases the contribution of KCa channels among endothelium-dependent vasodilatory mechanisms to maintain vascular and blood flow responses to muscle contraction in this metabolic disease rat model. KEY POINTS: Microvascular dysfunction in type 2 diabetes impairs blood flow redistribution during exercise and limits the performance of skeletal muscle and may cause early fatigability. Endothelium-dependent hyperpolarization (EDH), which mediates vasodilatation in resistance arteries, is known to be depressed in animals with diabetes. Here, we report that low-intensity exercise training in ZFDM rats increased the KCa channel-derived component in the vasodilator responses to muscle contraction compared to that in sedentary rats, partly as a result of the increase in KCNN3 expression. These results suggest that low-intensity exercise training improves blood flow redistribution in contracting skeletal muscle in metabolic disease with diabetes via upregulation of EDH.

Association of time-varying changes in physical activity with cardiac death and all-cause mortality after ICD or CRT-D implantation.

OBJECTIVETo evaluate the association of longitudinal changes in physical activity (PA) with long-term outcomes after implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) implantation.METHODSPatients with ICD/CRT-D implantation from SUMMIT registry were retrospectively analyzed. Accelerometer-derived PA changes over 12 months post implantation were obtained from the archived home monitoring data. The primary endpoints were cardiac death and all-cause mortality. The secondary endpoints were the first ventricular arrthymia (VA) and first appropriate ICD shock.RESULTSIn 705 patients, 446 (63.3%) patients showed improved PA over 12 months after implantation. During a mean 61.5-month follow-up duration, 99 cardiac deaths (14.0%) and 153 all-cause deaths (21.7%) occurred. Compared to reduced/unchanged PA, improved PA over 12 months could result in significantly reduced risks of cardiac death (improved PA ≤ 30 min: hazard ratio (HR) = 0.494, 95% CI: 0.288−0.848; > 30 min: HR = 0.390, 95% CI: 0.235−0.648) and all-cause mortality (improved PA ≤ 30 min: HR = 0.467, 95%CI: 0.299−0.728; > 30 min: HR = 0.451, 95% CI: 0.304−0.669). No differences in the VAs or ICD shocks were observed across different groups of PA changes. PA changes can predict the risks of cardiac death only in the low baseline PA group, but improved PA was associated with 56.7%, 57.4%, and 62.3% reduced risks of all-cause mortality in the low, moderate, and high baseline PA groups, respectively, than reduced/unchanged PA.CONCLUSIONSImproved PA could protect aganist cardiac death and all-cause mortality, probably reflecting better clinical efficacy after ICD/CRT-D implantation. Low-intensity exercise training might be encouraged among patients with different baseline PA levels.

Effects of low-intensity training on the brain and muscle in the congenital muscular dystrophy 1D model.

Congenital Muscular Dystrophy type 1D (MDC1D) is characterized by a hypoglycosylation of α-dystroglycan protein (α-DG), and this may be strongly implicated in increased skeletal muscle tissue degeneration and abnormal brain development, leading to cognitive impairment. However, the pathophysiology of brain involvement is still unclear. Low-intensity exercise training (LIET) is known to contribute to decreased muscle degeneration in animal models of other forms of progressive muscular dystrophies. The objective of this study was to analyze the effects of LIET on cognitive involvement and oxidative stress in brain tissue and gastrocnemius muscle. Male homozygous (Largemyd-/-), heterozygous (Largemyd+/-), and wild-type mice were used. To complete 28days of life, they were subjected to a low-intensity exercise training (LIET) for 8weeks. After the last day of training, 24h were expected when the animals were submitted to inhibitory avoidance and open-field test. The striatum, prefrontal cortex, hippocampus, cortex, and gastrocnemius were collected for evaluation of protein carbonylation, lipid peroxidation, and catalase and superoxide dismutase activity. LIET was observed to reverse the alteration in aversive and habituation memory. Increased protein carbonylation in the striatum, prefrontal cortex, and hippocampus and lipid peroxidation in the prefrontal cortex and hippocampus were also reversed by LIET. In the evaluation of the antioxidant activity, LIET increased catalase activity in the hippocampus and cortex. In the gastrocnemius, LIET decreased the protein carbonylation and lipid peroxidation and increased catalase and superoxide dismutase activity. In conclusion, it can be inferred that LIET for 8weeks was able to reverse the cognitive damage and oxidative stress in brain tissue and gastrocnemius muscle in MDC1D animals.

Protective effect by low-intensity downhill running training against muscle damage and oxidative stress after high-intensity downhill running in rats.

This study examined the effects of low-intensity eccentric exercise training performed before high-intensity eccentric exercise on muscle damage markers, oxidative stress and antioxidant defense. Twenty-two rats were divided into 3 groups; control (CON; n = 6), high-intensity eccentric exercise (HE; n = 8) and low-intensity eccentric exercise training plus high-intensity eccentric exercise (LET + HE; n = 8). Rats in the HE group performed HE at once. Rats in the LET + HE group performed LET and then HE protocol was applied. Blood and vastus intermedius muscle samples were taken 24 hours after the last exercise session for analyses of muscle damage, oxidative stress, and antioxidant defense markers. Muscle damage markers were higher in the HE group than the CON (137%-488%) and the LET + HE groups (82%-110%) (P < 0.05). Oxidative stress marker was higher in the HE group than the CON (65%) and the LET + HE (50%) groups (P < 0.05). Antioxidant defense markers were higher in the LTE + HE group than the HE group (39%-51%) (P < 0.05). In conclusion, low-intensity eccentric exercise training performed before high-intensity eccentric exercise conferred a protective effect against muscle damage by reducing oxidative stress and increasing antioxidant defense.

Respiratory and Circulatory Responses during Low-intensity Resistance Exercise Training Using a KAATSU Device in Male Patients with Cardiovascular Disease

Respiratory and Circulatory Responses during Low-intensity Resistance Exercise Training Using a KAATSU Device in Male Patients with Cardiovascular Disease

Beta-hydroxy-beta-methylbutyrate associated with low-intensity exercise training improves skeletal muscle regeneration through the IGF-Akt pathway.

The effect of beta-hydroxy-beta-methylbutyrate (HMB) supplementation associated with exercise training at different intensities and frequencies on skeletal muscle regeneration of muscle-injured rats was investigated. Male Wistar rats were divided into sedentary and trained groups. The sedentary groups were subdivided into non-injured (SED-Ct), non-injured supplemented with HMB (SED-Ct-HMB), injured (SED), and injured with HMB (SED-HMB), and the trained groups were injured, supplemented with HMB, and then divided into training three times a week without load (HT3) or with load (HT3L) and training five times a week without load (HT5) and with load (HT5L). The rats received a daily dose of HMB associated with 60 min of swimming with or without 5% body mass load for 14 days. On the 15th day, cryoinjury was performed in the right tibialis anterior muscle (TA), and 48 h later, supplementation and training continued for 15 days. After the last session, the TA was dissected and a cross-sectional area (CSA) of muscle fibers was used to determine the percentage of CSA fibers and connective tissue (%CT), as well as the total and phosphorylated protein contents. SED-HMB showed increased CSA and decreased %CT and TGF-β when compared to SED. HT3 showed increased CSA and reduced %CT accompanied by increased IGF-1/Akt, myogenin, and MuRF1, and decreased TGF-β. The CSA of HT5L also increased, but at the cost of a higher %CT compared to the other groups. Our results demonstrated that HMB associated with training without load and with lower frequency per week may be a valuable strategy for skeletal muscle regeneration.

The Effect of Online Low-intensity Exercise Training on Fitness and Cardiovascular Parameters

Online exercise is undoubtedly useful and important; however, chronic adaptations to online exercise, particularly strength gain, muscle hypertrophy, and cardiovascular parameters, remain unclear. We investigated the effect of online exercise training using Zoom on fitness parameters compared with the same exercises supervised directly. In the present study, 34 subjects (age: 42.9±14.4 years) were included. Twenty-three subjects performed 8 weeks of body mass-based exercise training online using Zoom, and eleven subjects performed the same exercise supervised directly as the control group. The subjects performed low-load resistance exercises twice a week for 8 weeks for a total of 16 sessions. The sessions included 9 exercises: leg raises, squats, rear raises, shoulder presses, rowing, dips, lunges, Romanian dead lifts, and push-ups. Chair-stand, push-up, and sit-and-reach tests were performed on all subjects. Overall, the home exercise program effectively increased strength and muscle mass and decreased blood pressure and arterial stiffness, but there were no differences between the groups. Changes in chair-stand and sit-and-reach test results were higher in the control group than in the online group. Our results show that there is a similar training response to body mass-based training in both groups, even with virtual experiences using Zoom.

The effect of exercise intensity on exercise-induced hypoalgesia in cancer survivors: A randomized crossover trial.

Pain is experienced by people with cancer during treatment and in survivorship. Exercise can have an acute hypoalgesic effect (exercise‐induced hypoalgesia; EIH) in healthy individuals and some chronic pain states. However, EIH, and the moderating effect of exercise intensity, has not been investigated in cancer survivors. This study examined the effect of low‐ and high‐intensity aerobic exercise on EIH in cancer survivors after a single exercise session as well as a brief period of exercise training (2‐weeks, three exercise sessions per week). Participants (N = 19) were randomized to low‐ (30%–40% Heart Rate Reserve (HRR) or high‐ (60%–70% HRR) intensity stationary cycling for 15–20 min. Pressure pain thresholds (PPT) were assessed over the rectus femoris and biceps brachii before and after a single exercise session and again after a short training period at the assigned intensity. Then, following a 6‐week washout period, the intervention was repeated at the other intensity. After the first exercise session, high‐intensity exercise resulted in greater EIH over the rectus femoris than low intensity (mean difference ± SE: −0.51 kg/cm2 ± 0.15, Cohen's d = 0.78, p = 0.004). After a 2‐week training period, we found no difference in EIH between intensities (0.01 kg/cm2 ± 0.25, d = 0.00 p = 0.99), with comparable moderate effect sizes for both low‐ and high‐intensity exercise, indicative of EIH. No EIH was observed over the biceps brachii of the arm at either low or high intensity. Low‐intensity exercise training may be a feasible option to increase pain thresholds in cancer survivors.

Physical exercise consequences on memory in obesity: A systematic review.

Obesity is associated with changes in memory. Thus, the aim of this systematic review was to investigate the physical exercise consequences on memory in obesity. A search was carried out in the PubMed, Lilacs, and Scielo databases with the following descriptors: "physical exercise," "memory," and "obesity." A total of 16 studies were analyzed in this review. Low, moderate, and high intensity exercise training showed positive effects on memory in patients with obesity (100%). The animal models of obesity used in their physical exercise protocols: treadmill (72.7%) or wheel running (27.3%). Most of the animal studies (81.8%) revealed positive effects of the physical exercise protocol on memory in obesity. Mouse was the most commonly used animal (54.5%), and a 60% high-fat diet (HFD) was the most commonly method used to induce obesity (82%). We did not identify any knockout model of obesity that was used to evaluate memory and used physical exercise as the main intervention. Thus, exercise training, independently if it is resistance or endurance training, seems to be an excellent intervention to prevent and inhibit cognitive impairment and memory loss on obese patients and animal models of obesity.

High Right Ventricular Afterload during Exercise in Patients with Pulmonary Arterial Hypertension.

The right ventricle (RV) is more sensitive to an increase in afterload than the left ventricle (LV), and RV afterload during exercise increases more easily than LV afterload. Pulmonary arterial hypertension (PAH)-specific therapy has improved pulmonary hemodynamics at rest; however, the pulmonary hemodynamic response to exercise is still abnormal in most patients with PAH. In these patients, RV afterload during exercise could be higher, resulting in a greater increase in RV wall stress. Recently, an increasing number of studies have indicated the short-term efficacy of exercise training. However, considering the potential risk of promoting myocardial maladaptive remodeling, even low-intensity repetitive exercise training could lead to long-term clinical deterioration. Further studies investigating the long-term effects on the RV and pulmonary vasculature are warranted. Although the indications for exercise training for patients with PAH have been expanding, exercise training may be associated with various risks. Training programs along with risk stratification based on the pulmonary hemodynamic response to exercise may enhance the safety of patients with PAH.

Low-Intensity Exercise Improves Aerobic Exercise Capacity in Rats After Myocardial Infarction and the Possible Role of Skeletal Muscle Autophagy

Abstract Background To investigate the effects of low-intensity exercise on aerobic exercise capacity and autophagy of skeletal muscle in rats after myocardial infarction (MI) and its possible mechanisms. Methods Thirty male Sprague Dawley rats, weighing 180–200 g, were randomly divided into sham, MI, and MI with exercise training (MI + Ex) groups. MI was induced by ligation of the left anterior descending artery. One week after surgery, low-intensity exercise training was carried out on a treadmill 5 days per week for 4 weeks. Results Infarct size of MI and MI + Ex groups was 30.8 ± 5.5% and 27.6 ± 5.0% of left ventricle, respectively (P &amp;gt; 0.05). Heart weight and heart to body weight ratio in the MI group were significantly higher than those in the sham group (P &amp;lt; 0.01), and were lowered by exercise training (P &amp;lt; 0.01). The maximal exercise distance and duration in the MI group were lower than those in the sham group (P &amp;lt; 0.01), but were significantly increased by exercise training (P &amp;lt; 0.05). Autophagosome of the gastrocnemius was not detectable in the sham group, scattered in the MI group but clustered in the MI + Ex group. Microtubule-associated protein light chain 3 (LC3-I/II) and Beclin-1 protein levels in the gastrocnemius were similar between MI and sham groups, but were significantly higher in the MI + Ex group (P &amp;lt; 0.05). Conclusions Low-intensity exercise improves exercise capacity in rats after MI. The effect is associated with enhanced autophagy of the skeletal muscle.