Resistance Exercise Training in Patients with Heart Failure

Practical guidelines for exercise prescription in patients with chronic heart failure

Chronic heart failure (HF) is a major cause of morbidity, mortality, disability, and health care costs. A hallmark feature of HF is severe exercise intolerance, which is multifactorial and stems from central and peripheral pathophysiological mechanisms. Exercise training is internationally recognized as a Class 1 recommendation for patients with HF, regardless of whether ejection fraction is reduced or preserved. Optimal exercise prescription has been shown to enhance exercise capacity, improve quality of life, and reduce hospitalizations and mortality in patients with HF. This article will review the rationale and current recommendations for aerobic training, resistance training, and inspiratory muscle training in patients with HF. Furthermore, the review provides practical guidelines for optimizing exercise prescription according to the principles of frequency, intensity, time (duration), type, volume, and progression. Finally, the review addresses common clinical considerations and strategies when prescribing exercise in patients with HF, including considerations for medications, implantable devices, exercise-induced ischemia, and/or frailty.

Cardiovascular Benefits of Resistance Training in Patients With Heart Failure With Reduced Ejection Fraction: A Systematic Review

Cardiovascular diseases pose a serious problem for health globally. Among these, congestive heart failure is the leading cause of mortality and morbidity worldwide. According to the recent census, heart failure contributes to a huge financial burden annually. Exercise therapy is an integral part of the non-pharmacological management of heart failure. Due to the availability of various types of exercise therapies and rapid advancements in the existing evidence, it is often challenging to prescribe an appropriate exercise program. Although there is unequivocal evidence supporting the cardiovascular benefits of aerobic therapy, the incorporation of resistance training into exercise regimens should also be encouraged due to its effects on muscular endurance and ameliorating skeletal myopathy in heart failure. In this study, we used a systematic literature review (SLR) approach to give an overview of the current literature and highlight the cardiovascular benefits of resistance training, alone or in combination with aerobic training. We reviewed articles from well-recognized journals published between 2013 and 2023, finally narrowing down to nine selected papers for a thorough analysis. The inclusion criteria comprise studies dealing with heart failure with reduced ejection fraction (HFrEF), resistance training alone or in combination with aerobic therapy, and studies available for free in either the PubMed or Google Scholar databases. The systematic review revealed that resistance training in combination with aerobic therapy has greater cardiovascular benefits than either resistance or aerobic therapy alone. A few unique approaches, like periodic intermittent muscular exercise (PRIME) and super circuit training (SCT), have demonstrated an improvement in cardiac and non-cardiac clinical outcomes compared to conventional exercise therapies. Moreover, various factors, like lack of motivation and lack of time, contribute to poor adherence to exercise therapy. Approaches like telerehabilitation and designing exercise regimens with activities that patients enjoy have led to improvements in long-term adherence rates. Nevertheless, further exploration and research by conducting randomized controlled trials on a larger scale is essential to explore the potential of resistance training in the rehabilitation of patients with heart failure with reduced ejection fraction and to develop the most effective exercise therapy.

Exercise Mode in Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Optimising exercise prescription in heart failure (HF) with a preserved (HFpEF) or reduced (HFrEF) ejection fraction is clinically important. As such, the aim of this meta-analysis was to compare traditional moderate intensity training (MIT) against combined aerobic and resistance training (CT) and high-intensity interval training (HIIT) for improving aerobic capacity (VO₂), as well as other clinically relevant parameters.

METHODS

A comprehensive systematic search was performed to identify randomised controlled trials published between 1990 and May 2021. Research trials reporting the effects of MIT against CT or HIIT on peak VO₂ in HFpEF or HFrEF were considered. Left-ventricular ejection fraction (LVEF) and various markers of diastolic function were also analysed.

RESULTS

Seventeen studies were included in the final analysis, 4 of which compared MIT against CT and 13 compared MIT against HIIT. There were no significant differences between MIT and CT for peak VO₂ (weighted mean difference [WMD]: 0.521 ml min^-1 kg^-1, [95% CI] =  - 0.7 to 1.8, P_fixed = 0.412) or LVEF (WMD: - 1.129%, [95% CI] =  - 3.8 to 1.5, P_fixed = 0.408). However, HIIT was significantly more effective than MIT at improving peak VO₂ (WMD: 1.62 ml min^-1 kg^-1, [95% CI] = 0.6-2.6, P_random = 0.002) and LVEF (WMD: 3.24%, [95% CI] = 1.7-4.8, P_random < 0.001) in HF patients. When dichotomized by HF phenotype, HIIT remained significantly more effective than MIT in all analyses except for peak VO₂ in HFpEF.

CONCLUSIONS

HIIT is significantly more effective than MIT for improving peak VO₂ and LVEF in HF patients. With the exception of peak VO₂ in HFpEF, these findings remain consistent in both phenotypes. Separately, there is no difference in peak VO₂ and LVEF change following MIT or CT, suggesting that the addition of resistance exercise does not inhibit aerobic adaptations in HF.

Global Trends in Research of Mitochondrial Biogenesis over past 20 Years: A Bibliometric Analysis

Background

Mitochondrial biogenesis-related studies have increased rapidly within the last 20 years, whereas there has been no bibliometric analysis on this topic to reveal relevant progress and development trends.

Objectives

In this study, a bibliometric approach was adopted to summarize and analyze the published literature in this field of mitochondrial biogenesis over the past 20 years to reveal the major countries/regions, institutions and authors, core literature and journal, research hotspots and frontiers in this field.

Methods

The Web of Science Core Collection database was used for literature retrieval and dataset export. The CiteSpace and VOSviewer visual mapping software were used to explore research collaboration between countries/regions, institutions and authors, distribution of subject categories, core journals, research hotspots, and frontiers in this field.

Results

In the last 20 years, the annual number of publications has shown an increasing trend yearly. The USA, China, and South Korea have achieved fruitful research results in this field, among which Duke University and Chinese Academy of Sciences are the main research institutions. Rick G Schnellmann, Claude A Piantadosi, and Hagir B Suliman are the top three authors in terms of number of publications, while RC Scarpulla, ZD Wu, and P Puigserver are the top three authors in terms of cocitation frequency. PLOS One, Biochemical and Biophysical Research Communications, and Journal of Biological Chemistry are the top three journals in terms of number of articles published. Three papers published by Richard C Scarpulla have advanced this field and are important literature for understanding the field. Mechanistic studies on mitochondrial biosynthesis have been a long-standing hot topic; the main keywords include skeletal muscle, oxidative stress, gene expression, activation, and nitric oxide, and autophagy and apoptosis have been important research directions in recent years.

Conclusion

These results summarize the major research findings in the field of mitochondrial biogenesis over the past 20 years in various aspects, highlighting the major research hotspots and possible future research directions and helping researchers to quickly grasp the overview of the developments in this field.

Effects of different exercise programs on cardiorespiratory reserve in HFpEF: a systematic review and meta-analysis

HFpEF represents an heterogeneous syndrome with complex pathophysiologic substrate and multiple clinical manifestations. Much attention has been recently focused on cardiac rehabilitation programs for HFpEF patients and studies have examined the effects of exercise training on this specific population. This systematic review and meta-analysis included studies of adult patients with HFpEF and evaluated the impact of exercise on cardiorespiratory fitness variables measured during CPET. The primary outcome was the difference between groups in the change of peak oxygen uptake (Δpeak VO₂). Literature search involved PubMed/MEDLINE, Cochrane/CENTRAL and Scopus databases. From an initial 5,143 literature records, we identified 18 studies fulfilling inclusion criteria; 11 studies with 515 patients were finally included in primary outcome analysis. Δpeak VO₂ between baseline and study-end was significantly higher in the groups of exercise training versus control (WMD 2.25 ml/kg/min, 95%CI 1.81-2.70). Exercise training resulted in greater change in the 6MWT distance (WMD 2.25 meters, 95%CI 1.81-2.70). Health related quality of life (WMD: -3.36, 95%CI -9.42-2.70, I²=14%, p=0.33) and echocardiographic indexes of diastolic function showed no differences between exercise and control groups at study end. In subgroup analysis, no difference between resistance versus aerobic exercise was noted on Δpeak VO₂, but high intensity interval training showed greater increase in peak VO₂ versus aerobic exercise (WMD 1.62 ml/kg/min, 95%CI 0.96-2.29, I²=0%, p=0.82). Exercise training in HFpEF results in significant improvements in peak VO₂ and 6MWT distance compared to controls. High intensity interval training may offer greater enhancement of exercise capacity of these patients than standard aerobic exercise.

Prioritizing movement to address the frailty phenotype in heart failure

Frailty is a highly prevalent multisystem syndrome in older adults with heart failure (HF) and is associated with poor clinical prognosis and increased complexity of care. While frailty is neither disease nor age specific, it is a clinical manifestation of aging-related processes that reflects a reduced physiological ability to tolerate and recover from stress associated with aging, disease, or therapy. Within this context, physical frailty, which is distinctly oriented to physical functional domains (e.g., muscle weakness, slowness, and low activity), has been recognized as a critical vital sign in older persons with HF. Identification and routine assessment of physical frailty, using objective physical performance measures, may guide the course of patient-centered treatment plans that maximize the likelihood of improving clinical outcomes in older HF patients. Exercise-based rehabilitation is a primary therapy to improve cardiovascular health in patients with HF; however, the limited evidence supporting the effectiveness of exercise tailored to older and frail HF patients underscores the current gaps in management of their care. Interdisciplinary exercise interventions designed with consideration of physical frailty as a therapeutic target may be an important strategy to counteract functional deficits characteristic of frailty and HF, and to improve patient-centered outcomes in this population. The purpose of this current review is to provide a better understanding of physical frailty and its relation to management of care in older patients with HF. Implications of movement-based interventions, including exercise and physical rehabilitation, to prevent or reverse physical frailty and improve clinical outcomes will further be discussed.

Lean Mass Abnormalities in Heart Failure: The Role of Sarcopenia, Sarcopenic Obesity, and Cachexia

The role of body composition in patients with heart failure (HF) has been receiving much attention in the last few years. Particularly, reduced lean mass (LM), the best surrogate for skeletal muscle mass, is independently associated with abnormal cardiorespiratory fitness (CRF) and muscle strength, ultimately leading to reduced quality of life and worse prognosis. While in the past, reduced CRF in patients with HF was thought to result exclusively from cardiac dysfunction leading to reduced cardiac output at peak exercise, current evidence supports the concept that abnormalities in LM may also play a critical role. Abnormalities in the LM body composition compartment are associated with the development of sarcopenia, sarcopenic obesity, and cachexia. Such conditions have been implicated in the pathophysiology and progression of HF. However, identification of such conditions remains challenging, as universal definitions for sarcopenia, sarcopenic obesity, and cachexia are lacking. In this review article, we describe the most common body composition abnormalities related to the LM compartment, including skeletal and respiratory muscle mass abnormalities, and the consequences of such anomalies on CRF and muscle strength in patients with HF. Finally, we discuss the potential nonpharmacologic therapeutic strategies such as exercise training (ie, aerobic exercise and resistance exercise) and dietary interventions (ie, dietary supplementation and dietary patterns) that have been implemented to target body composition, with a focus on HF.

Blood Pressure Increase in Hypertensive Individuals During Resistance Training Protocols With Equated Work to Rest Ratio

Introduction: Despite growing evidence regarding the benefits of resistance training in hypertension, the large and abrupt rise of systolic blood pressure (SBP) observed during resistance exercise execution has resulted in concern about its safety. However, the manipulation of the resistance training protocol (RTP) organization, maintaining the work to rest ratio equated between protocols (W:R-equated), may reduce the SBP increase.

Purpose: To compare cardiovascular responses during two W:R-equated RTPs (3 × 15:88 s vs. 9 × 5:22 s – sets × reps: rest between sets) performed in exercises for the lower and upper limbs.

Methods: Twelve medicated hypertensives (48 ± 8 years) randomly performed two RTPs in the bilateral leg extension (BLE) and unilateral elbow flexion (UEF) exercises at 50% 1RM. Increases (Δ) of SBP, heart rate (HR) and rate pressure product (RPP) during the exercises were measured by photoplethysmography.

Results: In both BLE and UEF exercises, Δ SBP was significantly greater during 3 × 15:88 s than 9 × 5:22 s (peak values: BLE = + 84 ± 39 vs. + 67 ± 20 mm Hg, and UEF = + 46 ± 25 vs. + 37 ± 18 mm Hg, respectively, both p < 0.05). ΔHR and ΔRPP were significantly higher in the 3 × 15:88 s than 9 × 5:22 s in BLE (peak values + 45 ± 17 vs. + 30 ± 8 bpm, and + 15,559 ± 5570 vs. + 10,483 ± 2614 mm Hg. bpm).

Conclusion: In medicated hypertensives, a RTP combining more sets with less repetitions per set and shorter rest intervals between sets (i.e., 9 × 5:22 s) produced a smaller increase in cardiovascular load (ΔSBP, ΔHR and ΔRPP) during its execution than a protocol with fewer longer sets (i.e., 3 × 15:88 s).

Effect of Blood Flow Restricted Resistance Exercise and Remote Ischemic Conditioning on Functional Capacity and Myocellular Adaptations in Patients With Heart Failure

BACKGROUND

Patients with congestive heart failure (CHF) have impaired functional capacity and inferior quality of life. The clinical manifestations are associated with structural and functional impairments in skeletal muscle, emphasizing a need for feasible rehabilitation strategies beyond optimal anticongestive medical treatment. We investigated whether low-load blood flow restricted resistance exercise (BFRRE) or remote ischemic conditioning (RIC) could improve functional capacity and quality of life in patients with CHF and stimulate skeletal muscle myofibrillar and mitochondrial adaptations.

METHODS

We randomized 36 patients with CHF to BFRRE, RIC, or nontreatment control. BFRRE and RIC were performed 3× per week for 6 weeks. Before and after intervention, muscle biopsies, tests of functional capacity, and quality of life assessments were performed. Deuterium oxide was administered throughout the intervention to measure cumulative RNA and subfraction protein synthesis. Changes in muscle fiber morphology and mitochondrial respiratory function were also assessed.

RESULTS

BFRRE improved 6-minute walk test by 39.0 m (CI, 7.0-71.1, P=0.019) compared with control. BFRRE increased maximum isometric strength by 29.7 Nm (CI, 10.8-48.6, P=0.003) compared with control. BFRRE improved quality of life by 5.4 points (CI, -0.04 to 10.9; P=0.052) compared with control. BFRRE increased mitochondrial function by 19.1 pmol/s per milligram (CI, 7.3-30.8; P=0.002) compared with control. RIC did not produce similar changes.

CONCLUSIONS

Our results demonstrate that BFRRE, but not RIC, improves functional capacity, quality of life, and muscle mitochondrial function. Our findings have clinical implications for rehabilitation of patients with CHF and provide new insights on the myopathy accompanying CHF.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03380663.

Resistance Isn't Futile: The Physiological Basis of the Health Effects of Resistance Exercise in Individuals With Type 1 Diabetes

The importance of regular exercise for glucose management in individuals with type 1 diabetes is magnified by its acknowledgment as a key adjunct to insulin therapy by several governmental, charitable, and healthcare organisations. However, although actively encouraged, exercise participation rates remain low, with glycaemic disturbances and poor cardiorespiratory fitness cited as barriers to long-term involvement. These fears are perhaps exacerbated by uncertainty in how different forms of exercise can considerably alter several acute and chronic physiological outcomes in those with type 1 diabetes. Thus, understanding the bodily responses to specific forms of exercise is important for the provision of practical guidelines that aim to overcome these exercise barriers. Currently, the majority of existing exercise research in type 1 diabetes has focused on moderate intensity continuous protocols with less work exploring predominately non-oxidative exercise modalities like resistance exercise. This is surprising, considering the known neuro-muscular, osteopathic, metabolic, and vascular benefits associated with resistance exercise in the wider population. Considering that individuals with type 1 diabetes have an elevated susceptibility for complications within these physiological systems, the wider health benefits associated with resistance exercise may help alleviate the prevalence and/or magnitude of pathological manifestation in this population group. This review outlines the health benefits of resistance exercise with reference to evidence in aiding some of the common complications associated with individuals with type 1 diabetes.

Eficácia do treinamento resistido na melhora da capacidade funcional e na qualidade de vida de pacientes com insuficiência cardíaca: uma revisão sistemática e metanálise

RESUMO Avaliou-se a eficácia do treinamento resistido (TR) na melhoria da capacidade funcional (CF) e na qualidade de vida (QV) de pacientes com insuficiência cardíaca (IC). Uma busca eletrônica foi realizada em bancos de dados (PubMed, MEDLINE, Scopus, Web of Science, CINAHL, LILACS e Cochrane), sem restrições de linguagem ou ano de publicação, utilizando como descritores “heart failure”, “resistance training”, “exercise tolerance”, “quality of life”, “fatigue”, “dyspnea” e “muscle strength”. Foram incluídos ensaios clínicos, com amostra composta por indivíduos com IC, classe funcional I, II ou III da New York Heart Association; idade média <65 anos, sedentários, clinicamente estáveis e farmacologicamente otimizados; com fração de ejeção (FE) <45% do predito. A intervenção deveria ser o TR exclusivo. A descrição dos aspectos metodológicos pelo risco de viés e uma metanálise com uma análise por subgrupo foram executados. Sete estudos foram incluídos para análise qualitativa. O nível de concordância (índice kappa - k) entre os pesquisadores foi k=0,74. A maioria dos estudos que avalia CF e QV mostrou aumento no VO2 pico (pico de consumo de oxigênio) e nas pontuações finais dos questionários de QV para o grupo de intervenção. Os resultados de CF possibilitaram uma metanálise, exibindo um aumento final de 0,52 (0,17-0,87) mL.kg-1.min-1 (mililitros.quilograma-1.minuto-1) no VO2 pico depois do TR, com baixa heterogeneidade. Contudo, limitações estatísticas e diversidade de intervenções foram evidenciadas após a análise por subgrupos. As limitações encontradas nos estudos selecionados ainda não permitem considerar o TR eficaz na melhoria da CF e da QV em pacientes com IC.

Exercise-Based Rehabilitation for Heart Failure: Clinical Evidence

People with heart failure experience marked reduction in their exercise capacity which has detrimental effects on their activities of daily living, health-related quality of life, and ultimately their hospital ad-mission rate and mortality. Numerous cardiac rehabilitation studies have demonstrated functional benefits, improvement in quality of life and clinical outcomes from exercise training in patients with HFrEF. Based on evidences, the American College of Cardiology/American Heart Association, European Society of Cardiology, and National Institute for Health and Care Excellence(NICE) consistently recommend exercise-based cardiac rehabilitation(CR) as an effective and safe adjunct for patients with stable class II to III heart failure (HF) who do not have advanced arrhythmias and who do not have other limitations to exercise. This recommendation applies to patients with HFrEF as well as to patients with HFpEF besides patients with class IV HF, although the data are not as robust for patients with HFpEF. In this article, the clinical evidence on effects of exercise for HFrEF and HFpEF as well as end-stage heart failure were separately reviewed.

The effects of resistance training on muscle strength, quality of life and aerobic capacity in patients with chronic heart failure - A meta-analysis

BACKGROUND

Resistance training (RT) has been utilised to target muscle dysfunction associated with Chronic Heart Failure (CHF). However, there is limited meta-analysis evidence to support its use as a standalone therapy. This meta-analysis examined the effects of RT on muscle strength (one repetition maximum, 1RM and Peak Torque), aerobic capacity (VO_2peak and 6min walk distance) and quality of life (QoL) in patients with CHF.

METHODS

We searched Medline, EMBASE, Cochrane and CINAHL for studies published up to July 2016, combining terms related to the population (eg, heart failure, CHF) with terms for the intervention (eg, resistance, strength training) and the outcomes (eg, QoL, VO₂peak_,strength, aerobic capacity).

RESULTS

Ten studies including 240 participants were included in our meta-analysis (aged 48-76years, Ejection Fraction 18-37%). Training duration ranged from 8 to 24weeks and intensity up to 80% of 1RM. RT increased 1RM (standardised change score=0.60; 95% Confidence Interval: 0.43, 0.77) but not strength measured via peak torque at 60°/s^-1 and 180°/s^-1. RT increased VO_2peak (CSMD: 2.71ml/kg/min; 1.96, 3.45) and QoL (CSMD: -5.71; -9.85, -1.56).

CONCLUSION

RT as a single intervention can increase muscle strength, aerobic capacity and QoL in patients with CHF and may offer an alternative approach, particularly for those unable to participate in aerobic training. The effect of RT on muscle strength is mainly during slow controlled movements and not during rapid movements. Older adults and patients with advanced CHF are underrepresented in RT trials and future studies should seek to optimise their inclusion.

Assessing functional exercise capacity using telehealth: Is it valid and reliable in patients with chronic heart failure?

Introduction This study aimed to determine the validity and reliability of video-based telerehabilitation assessments in patients with heart failure. Methods Seventeen consecutive participants (mean age 69 years, SD 12 years and 88% males) undertook assessments of three functional tests via both telerehabilitation and face-to-face approaches, on the same day. The assessment order was randomised and conducted by independent assessors. Outcome measures included functional tests: timed up and go (time), six-minute walk (distance), grip strength (kilograms); system usability scale to rate participant experience with telerehabilitation assessment; and number of technical issues encountered. Validity and inter- and intra-rater reliability of telerehabilitation assessments were examined using limits of agreement, intra-class correlation coefficients (ICC), and paired t-tests. Results The limits of agreement for telerehabilitation assessments were within the clinically acceptable limits for timed up and go and grip strength. Telerehabilitation assessments for all functional tests were strongly associated with face-to-face assessments, with ICCs of between 0.85 and 0.96. Inter- and intra-rater reliability of telerehabilitation assessments for all functional tests were excellent (all ICC > 0.95). The mean (SD) system usability scale score was 85 (15)/100. Some incidences of Internet drop-outs, video freezing and auditory fading occurred. Discussion The use of telehealth for the assessment of functional exercise capacity appears to be valid and reliable in patients with heart failure.

Muscular strength as a strong predictor of mortality: A narrative review

Muscular strength, an important component of physical fitness, has an independent role in the prevention of chronic diseases whereas muscular weakness is strongly related to functional limitations and physical disability. Our purpose was to investigate the role of muscular strength as a predictor of mortality in health and disease. We conducted a systematic search in EMBASE and MEDLINE (1980-2014) looking for the association between muscular strength and mortality risk (all-cause and cause-specific mortality). Selected publications included 23 papers (15 epidemiological and 8 clinical studies). Muscular strength was inversely and independently associated with all-cause mortality even after adjusting for several confounders including the levels of physical activity or even cardiorespiratory fitness. The same pattern was observed for cardiovascular mortality; however more research is needed due to the few available data. The existed studies failed to show that low muscular strength is predictive of cancer mortality. Furthermore, a strong and inverse association of muscular strength with all-cause mortality has also been confirmed in several clinical populations such as cardiovascular disease, peripheral artery disease, cancer, renal failure, chronic obstructive pulmonary disease, rheumatoid arthritis and patients with critical illness. However, future studies are needed to further establish the current evidence and to explore the exact independent mechanisms of muscular strength in relation to mortality. Muscular strength as a modifiable risk factor would be of great interest from a public health perspective.

Feasibility of an Isometric Maximal Voluntary Contraction Test in Hematological Cancer Patients during Thrombocytopenia

Introduction. Resistance training is rarely offered to hemato-oncological patients in the daily clinical routine due to its potential harmful impact on the cardiovascular system and the long periods of thrombocytopenia experienced by these patients. Therefore, it is important to determine a valid assessment to define and control resistance training. In this study, the feasibility of a maximal voluntary contraction (MVC) test was investigated in hemato-oncological patients. This inexpensive assessment may be a practicable alternative to the one repetition maximum test which is currently described as the gold standard. Methods. 29 hemato-oncological patients with platelet counts between 30000/μL and 70000/μL were recruited for this pilot study. Complications like petechial bleedings, muscle convulsion, and pain were assessed using the Brief Pain Inventory before and 48 hours after the MVC test, which was performed unidirectionally for the quadriceps muscle. Results. We did not detect any statistically significant test-related exacerbations or pain development. Discussion. MVC testing seems to be a feasible method to control a resistance training program in hemato-oncological patients. Further studies need to extend their methods and, for example, compare the MVC test with the one repetition maximum test.

Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Oxidative function during exercise was evaluated in 11 young athletes with marked skeletal muscle hypertrophy induced by long-term resistance training (RTA; body mass 102.6 ± 7.3 kg, mean ± SD) and 11 controls (CTRL; body mass 77.8 ± 6.0 kg). Pulmonary O2 uptake (Vo2) and vastus lateralis muscle fractional O2 extraction (by near-infrared spectroscopy) were determined during an incremental cycle ergometer (CE) and one-leg knee-extension (KE) exercise. Mitochondrial respiration was evaluated ex vivo by high-resolution respirometry in permeabilized vastus lateralis fibers obtained by biopsy. Quadriceps femoris muscle cross-sectional area, volume (determined by magnetic resonance imaging), and strength were greater in RTA vs. CTRL (by ∼40%, ∼33%, and ∼20%, respectively). Vo2peak during CE was higher in RTA vs. CTRL (4.05 ± 0.64 vs. 3.56 ± 0.30 l/min); no difference between groups was observed during KE. The O2 cost of CE exercise was not different between groups. When divided per muscle mass (for CE) or quadriceps muscle mass (for KE), Vo2 peak was lower (by 15-20%) in RTA vs. CTRL. Vastus lateralis fractional O2 extraction was lower in RTA vs. CTRL at all work rates, during both CE and KE. RTA had higher ADP-stimulated mitochondrial respiration (56.7 ± 23.7 pmol O2·s(-1)·mg(-1) ww) vs. CTRL (35.7 ± 10.2 pmol O2·s(-1)·mg(-1) ww) and a tighter coupling of oxidative phosphorylation. In RTA, the greater muscle mass and maximal force and the enhanced mitochondrial respiration seem to compensate for the hypertrophy-induced impaired peripheral O2 diffusion. The net results are an enhanced whole body oxidative function at peak exercise and unchanged efficiency and O2 cost at submaximal exercise, despite a much greater body mass.

Lack of functional effects of neuromuscular electrical stimulation on skeletal muscle oxidative metabolism in healthy humans

A recent study has demonstrated that neuromuscular electrical stimulation (NMES) determines, in vitro, a fast-to-slow shift in the metabolic profile of muscle fibers. The aim of the present study was to evaluate if, in the same subjects, these changes would translate, in vivo, into an enhanced skeletal muscle oxidative metabolism. Seven young men were tested (cycle ergometer) during incremental exercises up to voluntary exhaustion and moderate and heavy constant-load exercises (CLE). Measurements were carried out before and after an 8-wk training program by isometric bilateral NMES (quadriceps muscles), which induced an ∼25% increase in maximal isometric force. Breath-by-breath pulmonary O2 uptake (V̇o2) and vastus lateralis oxygenation indexes (by near-infrared spectroscopy) were determined. Skeletal muscle fractional O2 extraction was estimated by near-infrared spectroscopy on the basis of changes in concentration of deoxygenated hemoglobin + myoglobin. Values obtained at exhaustion were considered “peak” values. The following functional evaluation variables were unaffected by NMES: peak V̇o2; gas exchange threshold; the V̇o2 vs. work rate relationship (O2 cost of cycling); changes in concentration of deoxygenated hemoglobin + myoglobin vs. work rate relationship (related to the matching between O2 delivery and V̇o2); peak fractional O2 extraction; V̇o2 kinetics (during moderate and heavy CLE) and the amplitude of its slow component (during heavy CLE). Thus NMES did not affect several variables of functional evaluation of skeletal muscle oxidative metabolism. Muscle hypertrophy induced by NMES could impair peripheral O2 diffusion, possibly counterbalancing, in vivo, the fast-to-slow phenotypic changes that were observed in vitro, in a previous work, in the same subjects of the present study.

A combined aerobic and resistance exercise program improves physical functional performance in patients with heart failure: a pilot study

BACKGROUND

Recent guidelines for exercise in patients with heart failure (HF) recommended aerobic and resistance exercise as being safe and effective; however, the clinical and functional significance of these combined training modalities has not been established. In this pilot study, combined aerobic and resistance training was hypothesized to improve physical function, muscle strength, and health-related quality of life (HRQOL) compared with an attention control wait list (ACWL).

METHODS

The 10-item Continuous Scale Physical Functional Performance Test (CS-PFP10), which simulates common household chores; muscle strength (handgrip and knee extension); and HRQOL (Kansas City Cardiomyopathy Questionnaire) were evaluated at baseline (T1) and at 12 weeks (T2). The home-based moderate-intensity walking and resistance training program was performed 5 days a week.

RESULTS

Twenty-four New York Heart Association class II to III HF patients (mean [SD] age, 60 [10] years; mean [SD] left ventricular ejection fraction, 25% [9%]) were randomized to a combined aerobic and resistance exercise program or to an ACWL group. Of the total group, 58% were New York Heart Association class III HF patients, 50% were white, and 50% were female. The CS-PFP10 total scores were significantly increased in the exercise group, from 45 (18) to 56 (16). The Kansas City Cardiomyopathy Questionnaire overall summary score was significantly improved (P < .001) at T2 in the exercise intervention group compared with the ACWL group.

CONCLUSIONS

Participants provided the home-based, combined aerobic and resistance exercise program had significantly improved physical function, muscle strength, symptom severity, and HRQOL compared with the ACWL group. The findings of this study must be interpreted cautiously owing to the limitations of a small sample, data collection from a single center, and differences between control and interventions groups at baseline. A combined aerobic and resistance exercise approach may improve physical function in stable HF patients, but further study in a larger, more diverse population is recommended. However, in this study, the CS-PFP10 instrument demonstrated its ability to identify functional health status in HF patients and thus warrants further testing in a larger sample for possible use in clinical practice.

Benefits of combined aerobic/resistance/inspiratory training in patients with chronic heart failure. A complete exercise model? A prospective randomised study

BACKGROUND

We hypothesised that combined aerobic training (AT) with resistance training (RT) and inspiratory muscle training (IMT) could result in additional benefits over AT alone in patients with chronic heart failure (CHF).

METHODS

Twenty-seven patients, age 58 ± 9 years, NYHA II/III and LVEF 29 ± 7% were randomly assigned to a 12-week AT (n=14) or a combined AT/RT/IMT (ARIS) (n=13) exercise program. AT consisted of bike exercise at 70-80% of max heart rate. ARIS training consisted of AT with RT of the quadriceps at 50% of 1 repetition maximum (1RM) and upper limb exercises using dumbbells of 1-2 kg as well as IMT at 60% of sustained maximal inspiratory pressure (SPI(max)). At baseline and after intervention patients underwent cardiopulmonary exercise testing, echocardiography, evaluation of dyspnea, muscle function and quality of life (QoL) scores.

RESULTS

The ARIS program as compared to AT alone, resulted in additional improvement in quadriceps muscle strength (1RM, p=0.005) and endurance (50%1 RM × number of max repetitions, p=0.01), SPI(max) (p<0.001), exercise time (p=0.01), circulatory power (peak oxygen consumption × peak systolic blood pressure, p=0.05), dyspnea (p=0.03) and QoL (p=0.03).

CONCLUSIONS

ARIS training was safe and resulted in incremental benefits in both peripheral and respiratory muscle weakness, cardiopulmonary function and QoL compared to that of AT. The present findings may add a new prospective to cardiac rehabilitation programs of heart failure patients whilst the clinical significance of these outcomes need to be addressed in larger randomised studies.

Exercício resistido no cardiopata: revisão sistemática

INTRODUÇÃO: A perda de massa muscular secundária à idade e à inatividade física é clinicamente relevante na população cardíaca; contudo, a prescrição do exercício resistido dinâmico para esses pacientes apresenta-se inconclusiva na literatura. OBJETIVOS: Reunir informações e apresentar as principais diretrizes relacionadas à prescrição de exercícios resistidos em cardiopatas. MATERIAIS E MÉTODOS: Foi realizada busca sistemática de literatura, a partir das bases de dados LILACS, SciELO e MEDLINE, utilizando os seguintes descritores na língua portuguesa: força muscular, exercício isométrico, esforço físico, cardiopatia e coronariopatia, e seus correspondentes na língua inglesa (muscle strength, isometric exercise, physical effort, heart disease e artery coronary disease), os quais foram pesquisados separadamente e em cruzamentos, sendo considerados para esta revisão apenas artigos publicados entre 2005 e 2010. RESULTADOS E DISCUSSÃO: De um total de 806 artigos foram selecionados 22 para integrar a revisão, sendo 14 estudos classificados como artigos originais, 2 artigos de atualização da literatura e 6 artigos de revisão, além do capítulo 8 do livro intitulado Diretrizes do ACSM (American College of Sports Medicine) para os testes de esforço e sua prescrição, publicado em 2007. CONCLUSÃO: O exercício resistido, independente da variada metodologia utilizada na prescrição dos componentes específicos do treinamento, mostrou-se eficiente para aumentar a força muscular de membros superiores e inferiores em cardiopatas e sua aplicação pode ser considerada segura para esses pacientes, desde que prescrito corretamente.

Exercise training in recently hospitalized heart failure patients enrolled in a disease management programme: design of the EJECTION-HF randomized controlled trial

AIMS

The Exercise Joins Education: Combined Therapy to Improve Outcomes in Newly-discharged Heart Failure (EJECTION-HF) study will evaluate the impact of a supervised exercise training programme (ETP) on clinical outcomes in recently hospitalized heart failure patients attending a disease management programme (DMP). Methods This multisite, pragmatic randomized controlled trial enrols patients discharged from participating hospitals with clinical evidence of heart failure who are willing and able to participate in a DMP and considered clinically safe to exercise. Enrolment includes participants with impaired and preserved left ventricular systolic function. Baseline assessment and programme commencement occur within 6 weeks of hospital discharge. The control group DMP includes individualized education and follow-up from a multidisciplinary heart failure team; a weekly education programme for 12 weeks; self-management advice; and medical follow-up. Home exercise is recommended for all participants. In addition, intervention participants are offered 36 supervised, structured gym-based 1 h exercise sessions over 24 weeks. Sessions are tailored to exercise capacity and include aerobic, resistance, and balance exercises. Enrolment target is 350 participants. Primary outcome is 12-month mortality and readmissions. Secondary outcomes include blinded evaluation of depressive symptoms, sleep quality, cognition, and functional status (activities of daily living, 6 min walk distance, grip strength) at 3 and 6 months. A cost-utility analysis will be conducted.

CONCLUSION

This study will enrol a representative group of hospitalized heart failure patients and measure a range of patient and health service outcomes to inform the design of post-hospital DMPs for heart failure. Enrolment will be completed in 2013. ACTRN12608000263392.

Resistance exercise in cardiac rehabilitation

Cardiovascular disease is the leading cause of death in developed nations, and there is a clear link with physical inactivity. The benefits of resistance training in patients with coronary heart disease are well documented and can contribute to secondary prevention of heart disease with corresponding improvements in patient survival. This review describes the benefits of resistance exercise for cardiac patients, details of its prescription in this group, and considers safety and contraindications.

Borg's scales in strength training; from theory to practice in young and older adults

This study is the first to apply Borg's psychophysical equation to measuring responses to strength training with weights machines. Theoretical constructs of Borg's scales were assessed in younger and older adults to estimate the appropriate load and number of repetitions required to meet recommended practice guidelines. A younger group (YG; 20 males, 20 females; aged 19-38 years) and older group (OG; 13 males, 13 females; aged 50-75 years) participated in 3 experiments. Experiment 1: YG performed 2-repetitions of incremented loads during triceps-elbow extensions and knee extensions to level 7 on Borg's CR10 Scale. Experiment 2: YG (n = 16) then performed 12-repetitions at the loads from experiment 1 that elicited CR10 ratings 1.5, 3.0, and 5.0. Experiment 3: OG performed 15-repetitions of "lat-pull" and leg press at 15-repetition maximum (RM) load. In experiments 2 and 3, CR10 or Borg RPE were measured every 2 repetitions. Experiment 1 revealed classic psychophysical response growth exponents between 1.1 and 1.8, which were greater in arms than legs (p < 0.001) and in females (p < 0.001). Theoretical estimates of 1RM were derived from the growth curves for the weights eliciting CR10 ratings of 1.5, 3, and 5. CR10 ratings of 3 to 6 fell within estimates of 40%-70% 1RM. Experiments 2 and 3 revealed, for constant load exercise "over time" (12 and 15 repetitions) from an initial CR10 rating of 4 to 6, a linear increase of 1 scale point for every 3 to 4 repetitions. In conclusion, Borg's equation has been used to set theoretical estimates of a %1RM. Relevant to current practice guidelines was the ability to set appropriate loads in relation to performing recommended numbers of repetitions (e.g., if the CR10 rating is >6 after 2 repetitions, the weight is likely be too heavy to complete 12 to 15 repetitions).

Combined aerobic and resistance exercise program improves task performance in patients with heart failure

OBJECTIVES

To assess the effects of a home-based aerobic and resistance training program on the physical function of adults with New York Heart Association (NYHA) class II and III patients and systolic heart failure (HF).

DESIGN

Randomized controlled trial.

SETTING

Home based.

PARTICIPANTS

Stable patients (N=24; mean age, 60 ± 10 y; left ventricular ejection fraction, 25% ± 9%; 50% white; 50% women) with New York Heart Association (NYHA) classes II and III (NYHA class III, 58%) systolic heart failure (HF).

INTERVENTION

A 12-week progressive home-based program of moderate-intensity aerobic and resistance exercise. Attention control wait list participants performed light stretching and flexibility exercises.

MAIN OUTCOME MEASURES

A 10-item performance-based physical function measure, the Continuous Scale Physical Functional Performance test (CS-PFP10), was the major outcome variable and included specific physical activities measured in time to complete a task, weight carried during a task, and distance walked. Other measures included muscle strength, HRQOL (Minnesota Living With Heart Failure Questionnaire, Epworth Sleepiness Scale), functional capacity (Duke Activity Status Index), and disease severity (brain natriuretic peptide) levels.

RESULTS

After the exercise intervention, 9 of 10 specific task activities were performed more rapidly, with increased weight carried by exercise participants compared with the attention control wait list group. Exercise participants also showed significant improvements in CS-PFP10 total score (P<.025), upper and lower muscle strength, and HRQOL (P<.001) compared with the attention control wait list group. Adherence rates were 83% and 99% for the aerobic and resistance training, respectively.

CONCLUSIONS

Patients with stable HF who participate in a moderate-intensity combined aerobic and resistance exercise program may improve performance of routine physical activities of daily living by using a home-based exercise approach. Performance-based measures such as the CS-PFP10 may provide additional insights into physical function in patients with HF that more commonly used exercise tests may not identify. Early detection of subtle changes that may signal declining physical function that are amenable to intervention potentially may slow further loss of function in this patient population.

Tai chi enhances the effects of endurance training in the rehabilitation of elderly patients with chronic heart failure

Purpose. To assess if Tai Chi added to endurance training (ET) is more effective than ET alone in improving exercise tolerance and quality of life (QOL) of elderly patients with chronic heart failure (CHF). Design. Sixty CHF patients, age 73.8 ± 6 years, M/F 51/9, were enlisted. Thirty pts were randomized to combined training (CT) performing Tai Chi +ET and 30 patients to ET (ET only). Methods. At baseline and after 12 weeks all patients underwent 6-minute walking test (6MWT), assessment of amino terminal probrain natriuretic peptide (NT-pro BNP), quadriceps maximal voluntary contraction (MVC) and peak torque (PT), QOL questionnaire (MacNewQLMI), blood pressure (BP), and heart rate (HR). All patients performed 4 sessions of exercise/week. Results. Distance at 6mwt improved in both groups with significant between-groups differences (P = .031). Systolic BP and NT-proBNP decreased significant in the CT group compared to ET (P = .025) and P = .015), resp.). CT group had a greater significant improvement in physical perception (P = .026) and a significant increase of PT compared to ET group. Conclusions. The association of Tai Chi and ET improves exercise tolerance and QOL of patients with CHF more efficiently than ET.

Resistance training increases 6-minute walk distance in people with chronic heart failure: a systematic review

QUESTION

Does resistance training, either alone or as an adjunct to aerobic training, improve cardiac function, exercise capacity and quality of life in people with chronic heart failure?

DESIGN

Systematic review with meta-analysis of randomised trials.

PARTICIPANTS

Adults with stable chronic heart failure.

INTERVENTION

Progressive resistance exercise training, alone or as an adjunct to aerobic training.

OUTCOME MEASURES

Cardiac function, exercise capacity and quality of life.

RESULTS

241 participants from eight trials performed 2 to 6 months of moderate-intensity resistance training (50-75% of 1RM). Most programs consisted of 5 to 6 exercises for large limb and trunk muscles with two sets of 8 to 12 repetitions, three times a week. Resistance training significantly increased 6-minute walk distance (WMD 52 m, 95% CI 19 to 85) but not peak oxygen consumption (WMD 1.4 ml/kg/min, 95% CI -0.3 to 3.1). When used as an adjunct to aerobic training, resistance training did not significantly alter left ventricular ejection fraction (WMD -0.5%, 95% CI -4.3 to 3.3), peak oxygen consumption (WMD -0.7 ml/kg/min, 95% CI -2.3 to 1.0), or Minnesota Living with Heart Failure Questionnaire scores (WMD -0.9, 95% CI -5.4 to 3.7), compared with aerobic training alone.

CONCLUSION

Resistance training increased 6-minute walk distance compared to no training, but had no other benefits on cardiac function, exercise capacity, or quality of life if used alone or as an adjunct to aerobic training in people with chronic heart failure. However, further high quality, large scale, randomised trials are needed.

Exploring the therapeutic role of creatine supplementation

Creatine (Cr) plays a central role in energy provision through a reaction catalyzed by phosphorylcreatine kinase. Furthermore, this amine enhances both gene expression and satellite cell activation involved in hypertrophic response. Recent findings have indicated that Cr supplementation has a therapeutic role in several diseases characterized by atrophic conditions, weakness, and metabolic disturbances (i.e., in the muscle, bone, lung, and brain). Accordingly, there has been an evidence indicating that Cr supplementation is capable of attenuating the degenerative state in some muscle disorders (i.e., Duchenne and inflammatory myopathies), central nervous diseases (i.e., Parkinson's, Huntington's, and Alzheimer's), and bone and metabolic disturbances (i.e., osteoporosis and type II diabetes). In light of this, Cr supplementation could be used as a therapeutic tool for the elderly. The aim of this review is to summarize the main studies conducted in this field and to highlight the scientific and clinical perspectives of this promising therapeutic supplement.

Principles of exercise prescription for patients with chronic heart failure

Chronic heart failure (CHF) is a common and debilitating condition characterized by reduced exercise tolerance. While exercise training was once thought to be contraindicated for patients with CHF, a substantial body of data has been published over the last two decades to support the use of exercise programs for these patients. Improvements in exercise capacity, quality of life, and mortality have been demonstrated among patients with CHF who have participated in formal exercise programs. Exercise prescription is a means of assessing and interpreting clinical information and applying the principles of training to develop an appropriate regimen so that these benefits are achieved. The major principles of the exercise prescription are the mode, frequency, duration, and intensity. Importantly, safe and effective exercise prescription for patients with CHF requires more than the application of these principles; it also requires careful consideration of the individual patients' functional status, comorbid conditions, medications, contraindications, and personal goals and preferences. Recent studies have demonstrated that a wide spectrum of patients with CHF benefit from appropriately applied exercise training, including those with both systolic and diastolic dysfunction, atrial fibrillation, pacemakers, implantable cardioversion devices, and post-cardiac transplantation. Increasingly, the principles of exercise prescription are included as a component of comprehensive CHF management programs. Evidence has accumulated that CHF patients who participate in rehabilitation programs have better health outcomes in terms of reduced morbidity and mortality, as well as lower hospitalization rates and lower overall health care costs.

Resistance exercise in individuals with and without cardiovascular disease: 2007 update: a scientific statement from the American Heart Association Council on Clinical Cardiology and Council on Nutrition, Physical Activity, and Metabolism

Prescribed and supervised resistance training (RT) enhances muscular strength and endurance, functional capacity and independence, and quality of life while reducing disability in persons with and without cardiovascular disease. These benefits have made RT an accepted component of programs for health and fitness. The American Heart Association recommendations describing the rationale for participation in and considerations for prescribing RT were published in 2000. This update provides current information regarding the (1) health benefits of RT, (2) impact of RT on the cardiovascular system structure and function, (3) role of RT in modifying cardiovascular disease risk factors, (4) benefits in selected populations, (5) process of medical evaluation for participation in RT, and (6) prescriptive methods. The purpose of this update is to provide clinicians with recommendations to facilitate the use of this valuable modality.

Enhancement of isokinetic muscle strength with a combined training programme in chronic heart failure

BACKGROUND

Patients with congestive heart failure (CHF) exhibit an impaired exercised tolerance that dramatically limits their functional capacity and alters their quality of life.

DESIGN

The aim of this study was to compare the effects of two types of training programmes on isokinetic muscle strength and aerobic capacities in patients with CHF.

METHODS

A group of 23 stable CHF patients included consecutively followed an exercise training programme, 3 days a week for 8 weeks. The first group (P1, n=11) exercised on a cycloergometer for 45 min at 65% of peak VO2. The second group (P2, n=12) followed a 45-min combined bicycle and quadricipital strength training. Strength training consisted of 10 series of 10 repetitions at 70% of maximal voluntary force. Incremental maximal cardiopulmonary exercise tests as well as an isokinetic quadricipital dynamometry evaluation were performed before and after training.

RESULTS AND CONCLUSIONS

In P1, peak VO2 increased by 20% (22.3+/-4.9 versus 17.8+/-4.5 ml min(-1) kg(-1); P<0.05) without any significant change in isokinetic muscle strength. In P2, peak VO2 improved within the same range (20.5+/-2.8 versus 18.6+/-3.7 ml min(-1) kg(-1); P<0.01). This last rehabilitation programme significantly increased isokinetic muscle strength at each angular velocities (+10.5+/-13.5%, P<0.04; +5.6+/-7.0%, P<0.03; for 180 degrees s(-1) and 60 degrees s(-1) respectively). Only the combined endurance/strength training programme was associated with an improvement in both peak VO2 and peripheral muscle strength, two significant parameters of outcome and quality of life in CHF.

Exercise training for patients with cardiovascular disease

This review surveys effort training, a validated and recommended therapy, in patients with atheromatous cardiovascular disease. This true therapy reduces mortality by 25-35%, reduces clinical manifestations and complications (rhythm problems, thrombosis) and improves physical capacity, reintegration and quality of life. The effects are essentially linked to improved metabolic performance of muscles and reduced endothelial dysfunction, insulin resistance and neurohormonal abnormalities. Training also has an impact on the evolution of major risk factors, especially diabetes and arterial hypertension. The risks are limited as long as the contraindications are respected and the programmes supervised. The indications (stable angina, chronic heart failure, peripheral arterial disease) should be described more precisely by taking into account functional criteria: physical deconditioning, exclusion, compliance, mood swings, and seriousness of risk factors. The training programme should be tailor made and based on evaluation of the patient's adaptation to effort, in terms of frequency, intensity and duration of the exercises. Various types of exercise include overall or segmental physical training; concentric, eccentric, even isokinetic muscle contraction exercises; and proprioceptive rehabilitation. However, knowledge is lacking about the molecular mechanisms of the effects of training, the most effective intensity of effort, and strategies to develop physical activity in this ever-growing population for both primary and secondary prevention.