Combined aerobic and resistance exercise training improves functional capacity and strength in CHF

A comparison of the acute haemodynamic response to aerobic and resistance exercise in subjects with exercise-induced pulmonary arterial hypertension

BACKGROUND

Exercise-induced pulmonary arterial hypertension (EIPAH) is associated with reduced exercise capacity and abnormal central haemodynamic responses to maximal aerobic exercise. Aerobic and resistance exercise training are commonly employed to treat reduced exercise capacity; however, the haemodynamic response to aerobic and resistance exercise, at training intensities, in subjects with EIPAH is unknown.

METHODS

Fourteen subjects (11 with scleroderma, 12 females) with EIPAH underwent cardiopulmonary exercise testing on a cycle ergometer, a one-repetition maximum (1RM) strength test and resistance exercise at 40% and 60% of maximum on a bilateral leg press machine. All tests were performed with a pulmonary artery catheter in situ. Haemodynamic and symptomatic responses to aerobic and resistance exercise, performed at 40% of peak oxygen consumption and 40% of 1RM, and at 60% of peak oxygen consumption and 60% of 1RM, were compared. For maximal exercise, the highest haemodynamic responses recorded during the cycling and 1RM tests were compared.

RESULTS

There were no differences in haemodynamic or symptomatic responses between the two modalities of submaximal exercise. At maximal exercise, all haemodynamic and symptomatic responses were lower during resistance compared with aerobic exercise (p < 0.05).

CONCLUSIONS

At the intensities studied, lower-limb resistance exercise was well tolerated and was mostly associated with similar or lower haemodynamic responses compared with aerobic exercise, in subjects with EIPAH.

Impact of exercise training on arterial wall thickness in humans

Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been consistently reported in asymptomatic subjects and those with cardiovascular risk factors and diseases. In the present review, we summarize evidence pertaining to the impact of exercise and physical activity on arterial wall remodelling of the carotid artery and peripheral arteries in the upper and lower limbs. We consider the potential role of exercise intensity, duration and modality in the context of putative mechanisms involved in wall remodelling, including haemodynamic forces. Finally, we discuss the impact of exercise training in terms of primary prevention of wall thickening in healthy subjects and remodelling of arteries in subjects with existing cardiovascular disease and risk factors.

Australian perspective regarding recommendations for physical activity and exercise rehabilitation in pulmonary arterial hypertension

AIM

To determine the opinion of health care professionals within Australia, regarding acceptable levels of exertion and symptoms, and referral for exercise rehabilitation in patients with pulmonary arterial hypertension (PAH).

METHOD

In 2010, 76 health care professionals at a specialist pulmonary hypertension meeting in Australia were surveyed using a self-administered questionnaire. The questionnaire included case studies of patients with PAH in World Health Organization (WHO) functional classes II-IV. For each case study, respondents were asked to report their opinion regarding the acceptable level of exertion and symptoms during daily activities, and whether they would refer the patient for exercise rehabilitation. Three additional questions asked about advice in relation to four specific physical activities.

RESULTS

The response rate was 70% (n = 53). Overall, 58% of respondents recommended patients undertake daily activities 'as tolerated'. There was no consensus regarding acceptable levels of breathlessness or fatigue, but the majority of respondents considered patients should have no chest pain (73%) and no more than mild light-headedness (92%) during daily activities. Overall, 63% of respondents would have referred patients for exercise rehabilitation. There was little difference in opinion regarding the acceptable level of exertion or symptoms, or referral for exercise rehabilitation, according to functional class. However, the patients' functional class did influence the advice given regarding the specific physical activities.

CONCLUSION

In 2010, there were inconsistencies between individual health care professionals within Australia regarding appropriate levels of physical exertion and acceptable symptoms during daily activities. Almost two-thirds of the respondents reported they would refer patients for exercise rehabilitation.

Exercício físico aeróbico em mulheres com doença de Chagas

INTRODUÇÃO: A forma cardíaca da doença de Chagas causa modificações orgânicas e funcionais, sendo o exercício físico aeróbio uma alternativa de proposta terapêutica. OBJETIVO: avaliar o exercício físico aeróbio em mulheres com doença de Chagas crônica. MATERIAIS E MÉTODOS: Quatorze mulheres com doença de Chagas na faixa etária entre 40 e 60 anos, classe I da New York Heart Association (NYHA) foram divididas em dois grupos. Sete no G1 que realizaram exercício físico, com duas sessões diárias semanais por seis semanas e sete no G2 sem tal intervenção. O efeito do exercício físico foi avaliado por 27 variáveis fisioterapêuticas e ergoespirométricas no tempo zero (T0) e após seis semanas (T6). RESULTADO: No T6 em relação ao T0 a avaliação fisioterapêutica mostrou diferenças significativas na pressão arterial sistólica, no pico do fluxo expiratório, nas pressões inspiratória e expiratória máximas e na frequência cardíaca. Na ergoespirometria houve aumento significativo no DP máximo, no MET máximo, no estágio do protocolo de Bruce, no VO2 máximo, na duração do teste e na distância percorrida para as participantes de G1 e apenas na duração do teste para G2. Para G1 foi ainda observada em T6 uma diminuição significativa do duplo produto na intensidade moderada e alta na mesma carga de esforço. CONCLUSÃO: O treinamento aeróbio de curto período, de simples aplicação e com supervisão pode ser realizado com segurança, aumentando a tolerância ao exercício em pacientes com doença de Chagas crônica classe I da NYHA.

Clinical research in cardiac rehabilitation and secondary prevention: looking back and moving forward

Cardiac rehabilitation/secondary prevention (CR/SP) programs are considered standard of care and provide critically important resources for optimizing the care of cardiac patients. The objective of this article is to briefly review the evolution of CR/SP programs from a singular exercise intervention to its current, more comprehensive multifaceted approach. In addition, we offer perspective on critical concerns and suggest future research considerations to optimize the effectiveness and utilization of CR/SP program interventions.

Proteomic responses of skeletal and cardiac muscle to exercise

Regular exercise is effective in the prevention of chronic diseases and confers a lower risk of death in individuals displaying risk factors such as hypertension and dyslipidemia. Thus, knowledge of the molecular responses to exercise provides a valuable contrast for interpreting investigations of disease and can highlight novel therapeutic targets. While exercise is an everyday experience and can be conceptualized in simple terms, it is also a complex physiological phenomenon and investigation of exercise responses requires sophisticated analytical techniques and careful standardization of the exercise stimulus. Proteomic investigation of exercise is in its infancy but the ability to link changes in function with comprehensive changes in protein expression and post-translational modification holds great promise for advancing physiology. This article highlights recent pioneering work investigating the effects of exercise in skeletal and cardiac muscle that has uncovered novel mechanisms underlying the benefits of physical activity.

Current concepts underlying benefits of exercise training in congestive heart failure patients

The pathophysiology of several conditions including heart failure is partly attributable to a failure of the cell energy metabolism. Studies have shown that exercise training (ET) improves quality of life (QOL) and is beneficial in terms of reduction of symptoms, mortality and duration of hospitalization. Increasingly, ET is now achieving acceptance as complimentary therapy in addition to routine clinical practice in patients with chronic heart failure (CHF). However, the mechanisms underlying the beneficial effects of ET are far less understood and need further evaluation. Evidence suggests that while CHF induces generalized metabolic energy depletion, ET largely enhances the overall function of the heart muscle. Hence, research efforts are now aiming to uncover why ET is beneficial as a complimentary treatment of CHF in the context of improving endothelial function and coronary perfusion, decreasing peripheral resistance, induction of cardiac and skeletal muscle cells remodeling, increasing oxygen uptake, substrate oxidation, and resistance to fatigue. Here we discuss the current evidence that suggest that there are beneficial effects of ET on cardiac and skeletal muscle cells oxidative metabolism and intracellular energy transfer in patients with CHF.

Effects of interval cycle training with or without strength training on vascular reactivity in heart failure patients

BACKGROUND

Exercise training confers beneficial effects on vascular reactivity in patients with chronic heart failure (CHF). This randomized study compares the effects of interval cycle training combined with strength training versus interval training alone on vascular reactivity in CHF patients.

METHODS

Twenty-eight consecutive stable CHF patients (23 males, 53 ± 10 years, 28.4 ± 4.1 kg/m(2), left ventricular ejection fraction of 37 ± 12%) were randomly assigned to 3 times' weekly training sessions for 3 months, consisting of a) 40 minutes of interval cycle training (n = 14), versus b) 20 minutes of similar interval training plus 20 minutes of strength training of the quadriceps, hamstrings, muscles of the shoulder and biceps brachialis (n = 14). The work/recovery ratio of each session was 30/60 seconds. The intensity of interval training was set at 50% of the peak workload achieved at the steep ramp test (consisted of a 25-Watt increase on a cycle ergometer every 10 seconds until exhaustion). All patients underwent maximal, symptom-limited cardiopulmonary exercise testing and ultrasound evaluation of vascular reactivity by flow-mediated vasodilation (FMD) before and after the program.

RESULTS

A significant improvement in FMD was observed in the combined training group (P = 0.002), in contrast to the interval training alone group (P = NS); the improvement was significantly greater in the combined training than in the interval training alone group (P < .05). Peak oxygen uptake increased significantly and similarly in both groups, in the interval training group (P = .03), and in the combined training group (P = .006). No significant correlation was found between FMD improvement and cardiopulmonary exercise parameters.

CONCLUSIONS

A combined high-intensity, interval cycle exercise with strength training induces a greater beneficial effect on vascular reactivity rather than interval exercise training alone in CHF patients.

Short term effects of exercise training on exercise capacity and quality of life in patients with pulmonary arterial hypertension: protocol for a randomised controlled trial

BACKGROUND

Advances in the understanding and management of pulmonary arterial hypertension have enabled earlier diagnosis and improved prognosis. However, despite best available therapy, symptoms of exertional dyspnoea and fatigue are commonly reported and result in a reduced capacity to perform daily activities and impaired quality of life. Exercise training has demonstrated efficacy in individuals with other respiratory and cardiovascular diseases. Historically, however, exercise training has not been utilised as a form of therapy in pulmonary arterial hypertension due to the perceived risk of sudden cardiac death and the theoretical possibility that exercise would lead to worsening pulmonary vascular haemodynamics and deterioration in right heart function. Now, with the advances in pharmaceutical management, determining the safety and benefits of exercise training in this population has become more relevant. Only three studies of supervised exercise training in pulmonary arterial hypertension have been published. These studies demonstrated improvements in exercise capacity and quality of life, in the absence of adverse events or clinical deterioration. However, these studies have not utilised an outpatient-based, whole body exercise training program, the most common format for exercise programs within Australia. It is uncertain whether this form of training is beneficial and capable of producing sustained benefits in exercise capacity and quality of life in this population.

DESIGN/METHODS

This randomised controlled trial will determine whether a 12 week, outpatient-based, supervised, whole body exercise training program, followed by a home-based exercise program, is safe and improves exercise capacity and quality of life in individuals with pulmonary arterial hypertension. This study aims to recruit 34 subjects who will be randomly allocated to the exercise group (supervised exercise training 3 times a week for 12 weeks, followed by 3 sessions per week of home exercise for 12 weeks) or the control group (usual medical care). Subjects will be assessed at baseline, 12 weeks and 24 weeks.

DISCUSSION

This study will determine whether outpatient-based, whole body exercise training is beneficial and safe in individuals with pulmonary arterial hypertension. Additionally, this study will contribute to clinical practice guidelines for this patient population.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609000502235.

Clinical utility of exercise training in chronic systolic heart failure

The volume of literature attesting to the clinical benefits of exercise training in patients with stable chronic heart failure (CHF) is substantial. Training can improve symptoms and exercise capacity, as well as reducing morbidity, mortality, and rates of emergency hospitalization. These benefits are apparent in all patients with stable CHF, irrespective of age or sex, or the etiology or severity of heart failure. Training regimens for patients with stable, systolic CHF should form part of a comprehensive heart-failure support effort and are best delivered using supervised in-hospital exercise combined with some training at home or in a group setting in community centers. In this Review, the modes and intensity of exercise training, selection of patients, duration of training effects, and other clinical guidance for using this treatment option are discussed.

The Impact of Exercise Training on Conduit Artery Wall Thickness and Remodeling in Chronic Heart Failure Patients

Exercise training is an important adjunct to medical therapy in chronic heart failure, but the extent to which exercise impacts on conduit artery remodeling is unknown. The aim of this study was to evaluate the impact of aerobic and resistance exercise training modalities on arterial remodeling in patients with chronic heart failure. We randomized 36 untrained subjects with chronic heart failure to resistance training (58.8±3.5 years), aerobic training (61.3±2.8 years), or an untrained control group (64.4±2.4 years). Peak oxygen consumption during cycle ergometry increased after 12 weeks in both the resistance and aerobic training ( P <0.001) groups, but not in controls, whereas leg strength only increased after resistance training ( P <0.05). Brachial artery wall thickness decreased in the resistance training group (475±10 versus 443±13 μm; P <0.01), whereas no changes were apparent in the aerobic or control groups. Brachial diameter increased by ≈6% and ≈5% in the aerobic training and resistance training groups ( P <0.01), with no change evident in the control group. The wall:lumen ratio consequently declined in the resistance training group at 12 weeks (0.121±0.004 versus 0.107±0.004; P <0.01) and increased in the control group (0.111±0.006 versus 0.121±0.009; P <0.05). No wall:lumen change was evident in the aerobic training group. Our findings suggest that exercise has a systemic impact on remodeling of conduit arteries in humans and that resistance exercise training may be advantageous in subjects with chronic heart failure in this regard.

Effects of interval exercise training on respiratory drive in patients with chronic heart failure

BACKGROUND

Patients with chronic heart failure (CHF) suffer from ventilatory abnormalities. This study examined the effects of interval exercise training on the respiratory drive in CHF patients.

METHODS

Forty-six clinically stable CHF patients (38 males/8 women, mean age = 53 +/- 11 years) participated in an exercise rehabilitation program (ERP) 3 times/week, for 12 weeks by interval training modality with or without the addition of resistance training. All patients underwent symptom-limited cardiopulmonary exercise testing (CPET), and measurements of mouth occlusion pressure at 100 ms (P(0.1)) and maximum inspiratory muscle strength (P(Imax)) before and after ERP. Respiratory drive was estimated by mouth occlusion pressure P(0.1) and P(0.1)/P(Imax) ratio at rest, and the ventilatory pattern by resting mean inspiratory flow (V(T)/T(I)) and by V(T)/T(I) at identical CPET workloads, before and after ERP. We also studied a control non exercising group of 11 patients (8 men and 3 women).

RESULTS

P(0.1) at rest decreased from 3.04 +/- 1.52 to 2.62 +/- 0.9 cmH(2)O (p = 0.015), P(0.1)/P(Imax) % at rest from 4.56 +/- 3.73 to 3.69 +/- 2.03 (p = 0.006), resting V(T)/T(I) from 0.44 +/- 0.10 to 0.41 +/- 0.10 l/s (p = 0.014), and V(T)/T(I) at identical work rate from 2.13 +/- 0.59 to 1.93 +/- 0.58 l/s (p = 0.001) after ERP. VO(2) at peak exercise increased from 16.3 +/- 4.8 to 18.5 +/- 5.3 ml/kg/min (p < 0.001) in the exercise group. No improvement was noted in the control group.

CONCLUSIONS

ERP by interval training improves the respiratory drive and ventilatory pattern at rest and during exercise in CHF patients.

Modification of vascular function after handgrip exercise training in 73- to 90-yr-old men

PURPOSE

To examine the influence of a unilateral exercise training protocol on brachial artery reactivity (BAR) in 12 men (aged 81 +/- 5 yr).

METHODS

Brachial artery diameters and blood flow parameters were assessed, in both arms, using high-resolution ultrasonography, before and after 5 min of forearm occlusion, before and at the end of each week of a 4-wk training program. Training consisted of a unilateral handgrip training protocol (nondominant arm) at 60% of maximal voluntary handgrip strength, performed for 4 wk, 4 d x wk(-1), 20 min per session, and a cadence of one contraction per 4 s.

RESULTS

After training, handgrip strength increased 6.2% (baseline = 32.4 +/- 7.0 kg vs week 4 = 34.4 +/- 6.7 kg) in the trained arm only but failed to reach statistical significance (P = 0.10). No statistical changes were observed for blood pressure or resting HR. In contrast, BAR increased 45% (Pre = 2.9% vs Post = 4.1%, P = 0.05) in the trained arm only. Improvements in BAR were observed after the second week of training, without significant changes in the main vasodilatory trigger, defined as the relevant shear stimulus after forearm occlusion (P > 0.05).

CONCLUSIONS

These data indicate that a localized short-term exercise program results in significant improvements in vascular function in the trained arm of elderly men compared with the control arm. Furthermore, the findings indicate a statistically significant increase in BAR at the end of the second week of training, despite a similar trigger for dilation versus before training.

Arterial prehabilitation: can exercise induce changes in artery size and function that decrease complications of catheterization?

Coronary angiography and angioplasty are common invasive procedures in cardiovascular medicine, which involve placement of a sheath inside peripheral conduit arteries. Sheath placement and catheterization can be associated with arterial thrombosis, spasm and occlusion. In this paper we review the literature pertaining to the possible benefits of arterial 'prehabilitation'--the concept that interventions aimed at enhancing arterial function and size (i.e. remodelling) should be undertaken prior to cardiac catheterization or artery harvest during bypass graft surgery. The incidence of artery spasm, occlusion and damage is lower in larger arteries with preserved endothelial function. We conclude that the beneficial effects of exercise training on both artery size and function, which are particularly evident in individuals who possess cardiovascular diseases or risk factors, infer that exercise training may reduce complication rates following catheterization and enhance the success of arteries harvested as bypass grafts. Future research efforts should focus directly on examination of the 'prehabilitation' hypothesis and the efficacy of different interventions aimed at reducing clinical complications of common interventional procedures.

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.

Impact of inactivity and exercise on the vasculature in humans

The effects of inactivity and exercise training on established and novel cardiovascular risk factors are relatively modest and do not account for the impact of inactivity and exercise on vascular risk. We examine evidence that inactivity and exercise have direct effects on both vasculature function and structure in humans. Physical deconditioning is associated with enhanced vasoconstrictor tone and has profound and rapid effects on arterial remodelling in both large and smaller arteries. Evidence for an effect of deconditioning on vasodilator function is less consistent. Studies of the impact of exercise training suggest that both functional and structural remodelling adaptations occur and that the magnitude and time-course of these changes depends upon training duration and intensity and the vessel beds involved. Inactivity and exercise have direct "vascular deconditioning and conditioning" effects which likely modify cardiovascular risk.

Resistance exercise training improves heart function and physical fitness in stable patients with heart failure

PURPOSE

This study determined the effect of a structured isotonic strength training (ST) program on left ventricular (LV) function (ejection fraction, stroke volume, and end-diastolic and end-systolic volumes) and physical fitness (6-minute walk test, upper body strength, lower body strength, and body composition) in patients with New York Heart Association class II and III heart failure.

METHODS

Sixteen patients were randomized into 2 groups, ST and usual care. The ST group (10 patients) performed 24 ST exercise sessions (3 per week, 8 weeks), while the usual care (6 patients) group followed routine medical care. The structured isotonic ST program involved 12 different exercises on circuit weight machines. LV function (3D echocardiography) and physical fitness were assessed at baseline and 8 weeks.

RESULTS

Modest improvements (P < .05) in resting ejection fraction (0.32-0.37) and stroke volume (46 to 53 mL/beat), as well as in muscular strength and 6-minute walk distance, were found after training.

CONCLUSIONS

A short-term structured isotonic ST program appears to improve selected measures of resting LV function and fitness in patients with mild congestive heart failure. Additional studies utilizing larger numbers of subjects, including women, are needed.

Relationships of cardiac, pulmonary, and muscle reserves and frailty to exercise capacity in older women

BACKGROUND

A decline in exercise capacity (EC) is a characteristic of frailty. We hypothesized that decline is the effect of decrements in several physiological systems. We assessed whether the relationship of three main physiological systems-cardiac, pulmonary, and musculoskeletal-to EC is independent or interactive and whether their effect on EC varies with respect to frailty status.

METHODS

Observational study of 547 disabled women aged 65 years and older (Women's Health and Aging Study I) including 131 frail who participated in a test of EC. EC (seated step test), cardiac function (chronotropic index), pulmonary function (forced vital capacity, FVC), musculoskeletal function (quadriceps strength, QS), and frailty status were measured and interactive effects were modeled using linear regression and differentiation.

RESULTS

Each physiological system had a direct relationship with EC, which was lower in frail compared with nonfrail. The relationship between FVC and EC was positive and increased with increasing QS in nonfrail subjects. The effect of QS on EC was positive and increased with increasing FVC regardless of frailty. In subjects with low QS, frailty status was associated with lower EC and this effect became stronger with increasing FVC. Discussion Findings suggest but do not show that frailty status modifies the effects of physiological function in several systems on EC. Approaches to understanding emergent properties such as vulnerability to illness and death and clinical efforts to prevent and treat frailty should evaluate and possibly intervene on several physiological systems to be maximally effective.

Aerobic Exercise Intensity in Breast Cancer Patients: A Preliminary Investigation

Purpose: This study compared the heart rate (HR), rate of perceived exertion (RPE), and blood lactate (BL) responses to aerobic exercise between posttreated breast cancer patients and apparently healthy, age-matched controls. Methods: Seven patients and 7 control subjects underwent a submaximal treadmill test for the estimation of Vo2max. Exercise intensities of 40%, 60%, and 70% of Vo2max were calculated from the treadmill test and randomly examined between groups during three 9-minute exercise bouts on 3 different days. Independent samples t tests were used to examine the HR, RPE, and BL responses at each intensity between groups. Results: No significant differences were observed between the control and patient groups for HR, RPE, and BL at 40% (101 ± 9 vs 101 ± 11 bpm, P = .979; 8 ± 1 vs 9 ± 3, P = .237; and 1.11 ± 0.73 vs 1.26 ± 0.64 mmol/L, P = .188, respectively) and 60% (127 ± 17 vs 117 ± 13 bpm, P = .523; 12 ± 2 vs 11 ± 3, P = .267, and 3.83 ± 2.48 vs 2.23 ± 1.65 mmol/L, P = .237, respectively) of Vo2max . At 70% of Vo2max, no significant differences were found for HR (151 ± 27 vs 135 ± 13 bpm, P = .704) and RPE (14 ± 1 vs 13 ± 3, P = .181), but lower BL responses were observed in the patient group (7.70 ± 1.62 vs 3.29 ± 1.08 mmol/L, P < .0005). Conclusions: The results suggest similar HR, RPE, and BL responses between patients and control subjects at 40%, 60%, and 70% of Vo2max , except for BL at 70% of Vo2max. The lower BL response in the patient group at 70% of Vo2max was somewhat unexpected. Further research is needed to confirm or refute the results of this study to allow for a clearer understanding of the physiological responses of breast cancer patients to aerobic exercise at moderate or higher intensities so that safer aerobic exercise prescriptions can be developed for this population.

Effects of aerobic or aerobic and resistance training on cardiorespiratory and skeletal muscle function in heart failure: a randomized controlled pilot trial

OBJECTIVE

To examined the effects of different training modalities on exercise capacity (Vo( 2peak)), systolic function, muscular strength and endurance and quality of life in heart failure patients.

DESIGN

Randomized controlled trial.

SETTING

Cardiac rehabilitation centre in Canada.

SUBJECTS

Forty-two individuals with heart failure (62 +/- 12 years; New York Heart Association (NYHA) classes I-III).

INTERVENTIONS

Aerobic training (n = 14), combined aerobic and resistance training (n = 15) or usual care (n = 13) three times per week for 12 weeks.

MAIN MEASURES

(1) Vo( 2peak) measured by symptom-limited graded exercise test on cycle ergometer; (2) systolic function assessed by two-dimensional echocardiography; (3) muscular strength and muscular endurance measured by one-repetition maximum procedure; and (4) quality of life assessed by questionnaires.

RESULTS

In the intention-to-treat analysis, neither aerobic nor combined aerobic and resistance training significantly improved Vo(2peak), systolic function or quality of life compared with usual care. However, combined aerobic and resistance training significantly improved upper extremity strength (40.7 (14.0)-48.5 (16.0) kg, P<0.05) and muscular endurance (5.7 (2.7)-11.6 (7.6) reps, P<0.05) compared with aerobic training or usual care. In compliant participants (exercise adherence 80%), Vo(2peak) increased in the aerobic group (16.9 (6.0)-19.0 (6.8), P= 0.026) and tended to increase in the combined training group (15.9 (5.0)-17.6 (5.6), P= 0.058) compared with usual care. Quality of life was improved in the aerobic group only.

CONCLUSIONS

Both aerobic and combined aerobic and resistance training are effective interventions to improve Vo(2peak) in compliant heart failure patients. Combined training may be more effective in improving muscle strength and endurance.

Sympathetic hyperactivity differentially affects skeletal muscle mass in developing heart failure: role of exercise training

Sympathetic hyperactivity (SH) is a hallmark of heart failure (HF), and several lines of evidence suggest that SH contributes to HF-induced skeletal myopathy. However, little is known about the influence of SH on skeletal muscle morphology and metabolism in a setting of developing HF, taking into consideration muscles with different fiber compositions. The contribution of SH on exercise tolerance and skeletal muscle morphology and biochemistry was investigated in 3- and 7-mo-old mice lacking both alpha(2A)- and alpha(2C)-adrenergic receptor subtypes (alpha(2A)/alpha(2C)ARKO mice) that present SH with evidence of HF by 7 mo. To verify whether exercise training (ET) would prevent skeletal muscle myopathy in advanced-stage HF, alpha(2A)/alpha(2C)ARKO mice were exercised from 5 to 7 mo of age. At 3 mo, alpha(2A)/alpha(2C)ARKO mice showed no signs of HF and preserved exercise tolerance and muscular norepinephrine with no changes in soleus morphology. In contrast, plantaris muscle of alpha(2A)/alpha(2C)ARKO mice displayed hypertrophy and fiber type shift (IIA --> IIX) paralleled by capillary rarefaction, increased hexokinase activity, and oxidative stress. At 7 mo, alpha(2A)/alpha(2C)ARKO mice displayed exercise intolerance and increased muscular norepinephrine, muscular atrophy, capillary rarefaction, and increased oxidative stress. ET reestablished alpha(2A)/alpha(2C)ARKO mouse exercise tolerance to 7-mo-old wild-type levels and prevented muscular atrophy and capillary rarefaction associated with reduced oxidative stress. Collectively, these data provide direct evidence that SH is a major factor contributing to skeletal muscle morphological changes in a setting of developing HF. ET prevented skeletal muscle myopathy in alpha(2A)/alpha(2C)ARKO mice, which highlights its importance as a therapeutic tool for HF.

Physical exercise improves the functional capacity and quality of life in patients with heart failure

OBJECTIVE

The purpose of this study was to investigate the effects of physical exercise on the functional capacity and quality of life in heart failure patients.

METHODS

Forty-two patients of both sexes with heart failure of NYHA class II and III with different etiologies were randomly divided into untrained or trained groups. The six-month exercise program consisted of aerobic training, muscle strength training, agility and joint flexibility activities. Physical fitness was evaluated by testing the performance on these trained components. Quality of life was evaluated by scored answers to a standardized questionnaire involving multiple domains.

RESULTS

Baseline values did not differ between groups. Improvement in the trained group was identified in all components of functional capacity when compared to the untrained group (p<0.001). Quality of life improved in the trained patients concerning physical, psychological, social and environmental domains (p<0.001), whereas no significant change was found in the untrained patients.

CONCLUSIONS

Guided and monitored physical exercise is safe and has the potential to improve functional capacity and quality of life in heart failure patients with multiple etiologies.

Group-based aerobic interval training in patients with chronic heart failure: Norwegian Ullevaal Model

BACKGROUND AND PURPOSE

The purpose of this case report is to describe the responses of 4 patients with chronic heart failure (CHF) to a novel rehabilitation program: a group-based, high-intensity, interval-training program that includes aerobic, resistance, flexibility, and balance activities.

CASE DESCRIPTION

Four patients (55-71 years of age) with CHF (New York Heart Association class III) participated in the rehabilitation program twice per week for 16 weeks. Outcome measures included a 6-minute walk test (6MWT), a cycle ergometer test (aerobic capacity), and a quality-of-life questionnaire.

OUTCOMES

Patients 1, 2, and 3 increased their aerobic capacity (17%, 25%, and 52%, respectively). Patient 4 did not complete the cycle ergometer test because of limitations associated with his pacemaker. All patients increased their 6MWT distance (117, 66, 135, and 143 m for patients 1, 2, 3, and 4, respectively). No adverse events were reported.

DISCUSSION

The Norwegian Ullevaal Model of cardiac rehabilitation is a novel high-intensity, interval-training program. The 4 patients with CHF in this case series who participated in this program experienced improvements in physical capacity and quality of life and had no adverse events. These results are consistent with recent evidence supporting the efficacy of high-intensity interval training in people with CHF. Randomized clinical trials are needed to evaluate the clinical efficacy of this group-based, high-intensity, aerobic interval-training program for patients with CHF.

Implications of chronic heart failure on peripheral vasculature and skeletal muscle before and after exercise training

The pathophysiology of chronic heart failure (CHF) is typically conceptualized in terms of cardiac dysfunction. However, alterations in peripheral blood flow and intrinsic skeletal muscle properties are also now recognized as mechanisms for exercise intolerance that can be modified by therapeutic exercise. This overview focuses on blood delivery, oxygen extraction and utilization that result from heart failure. Related features of inflammation, changes in skeletal muscle signaling pathways, and vulnerability to skeletal muscle atrophy are discussed. Specific focus is given to the ways in which perfusion and skeletal muscle properties affect exercise intolerance and how peripheral improvements following exercise training increase aerobic capacity. We also identify gaps in the literature that may constitute priorities for further investigation.

Exercise training delays cardiac dysfunction and prevents calcium handling abnormalities in sympathetic hyperactivity-induced heart failure mice

Exercise training (ET) is a coadjuvant therapy in preventive cardiology. It delays cardiac dysfunction and exercise intolerance in heart failure (HF); however, the molecular mechanisms underlying its cardioprotection are poorly understood. We tested the hypothesis that ET would prevent Ca2+ handling abnormalities and ventricular dysfunction in sympathetic hyperactivity-induced HF mice. A cohort of male wild-type (WT) and congenic α2A/α2C-adrenoceptor knockout (α2A/α2CARKO) mice with C57BL6/J genetic background (3–5 mo of age) were randomly assigned into untrained and exercise-trained groups. ET consisted of 8-wk swimming session, 60 min, 5 days/wk. Fractional shortening (FS) was assessed by two-dimensional guided M-mode echocardiography. The protein expression of ryanodine receptor (RyR), phospho-Ser2809-RyR, sarcoplasmic reticulum Ca2+ ATPase (SERCA2), Na+/Ca2+ exchanger (NCX), phospholamban (PLN), phospho-Ser16-PLN, and phospho-Thr17-PLN were analyzed by Western blotting. At 3 mo of age, no significant difference in FS and exercise tolerance was observed between WT and α2A/α2CARKO mice. At 5 mo, when cardiac dysfunction is associated with lung edema and increased plasma norepinephrine levels, α2A/α2CARKO mice presented reduced FS paralleled by decreased SERCA2 (26%) and NCX (34%). Conversely, α2A/α2CARKO mice displayed increased phospho-Ser16-PLN (76%) and phospho-Ser2809-RyR (49%). ET in α2A/α2CARKO mice prevented exercise intolerance, ventricular dysfunction, and decreased plasma norepinephrine. ET significantly increased the expression of SERCA2 (58%) and phospho-Ser16-PLN (30%) while it restored the expression of phospho-Ser2809-RyR to WT levels. Collectively, we provide evidence that improved net balance of Ca2+ handling proteins paralleled by a decreased sympathetic activity on ET are, at least in part, compensatory mechanisms against deteriorating ventricular function in HF.

Exercise therapy for elderly heart failure patients

Exercise intolerance is one of the hallmark symptoms of heart failure (HF). Exercise training in this condition was not explored as a therapeutic modality until the past two decades. In fact, bed rest was promoted as a treatment for certain forms of HF in the 1970s. Over the past two decades, however, data have shown convincingly that exercise training can be implemented safely in patients who have HF, with significant improvement in functional capacity, various other physiologic variables, and quality of life. This article reviews the accumulated literature in this area, with specific emphasis on the effects of exercise training in older patients who have HF, a subset that may have the most to gain from such training.

Effects of a home-based exercise program on clinical outcomes in heart failure

BACKGROUND

The aim of this study was to determine the effects of a home-based exercise program on clinical outcomes. Exercise training improves exercise capacity in patients with heart failure (HF) but the long-term effects on clinical outcomes remain unknown.

METHODS

We randomized 173 patients with systolic HF to control (n = 87) or home-based exercise (n = 86). The primary end point was a composite of all-cause hospitalizations, emergency department admissions, urgent transplantation, and death at 12 months. Functional performance (as assessed by cardiopulmonary exercise testing and the 6-minute walk test), quality of life, and psychological states were measured at baseline, 3 months, and 6 months.

RESULTS

There was no significant difference between experimental and control groups in the combined clinical end point at 12 months and in functional status, quality of life, or psychological states over 6 months. Patients in the exercise group had a lower incidence of multiple (2 or more) hospitalizations compared with the control group: 12.8% versus 26.6%, respectively (P = .018).

CONCLUSIONS

A home-based walking program that incorporated aerobic and resistance exercise did not result in improved clinical outcomes at 1-year follow-up in this cohort of patients with systolic HF. However, the exercise program resulted in reduced rehospitalization rates.

Muscle Strength in Relation to Disease Severity in Patients with Congestive Heart Failure

OBJECTIVE

Indices of exercise capacity such as peak oxygen uptake (VO2peak) and muscle strength are important in association with reduced mortality. The present study compared differences in VO2peak and muscle strength indices (grip strength and knee extensor and flexor muscle strength) with disease severity and investigated the relation of these variables in congestive heart failure (CHF) patients.

DESIGN

The study comprised 102 patients with stable CHF (93 men, age 61.4 +/- 10.2 yrs) with left ventricular ejection fraction (LVEF) <40% by echocardiography. We used New York Heart Association (NYHA) functional class to index disease severity. VO2peak, grip strength, knee extensor, and flexor muscle strength were determined. Patients were divided into three groups by NYHA class: class I (n = 39), class II (n = 49), and class III (n = 14).

RESULTS

Age, sex, and LVEF did not differ according to NYHA class. VO2peak and all muscle strength indices decreased with increases in NYHA class (P < 0.05). VO2peak correlated positively with all muscle strengths (P < 0.05). Stepwise linear regression analysis revealed that grip and knee extensor strength were important in predicting VO2peak.

CONCLUSIONS

Exercise capacity and disease severity in CHF patients may be influenced not only by lower-limb but also upper-limb muscle strength.

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 Normalizes Sympathetic Outflow by Central Antioxidant Mechanisms in Rabbits With Pacing-Induced Chronic Heart Failure

BACKGROUND

In a recent study, we demonstrated that an increase in oxidative stress in the rostral ventrolateral medulla plays a critical role in the sympathoexcitation observed in chronic heart failure (CHF). Growing evidence indicates that exercise training evokes an antioxidative effect in CHF. In the present study, we therefore hypothesized that long-term exercise exerts its beneficial effect on autonomic activity in CHF via central antioxidative mechanisms.

METHODS AND RESULTS

Experiments were performed on New Zealand White rabbits. All rabbits were instrumented to measure mean arterial pressure, heart rate, and renal sympathetic nerve activity and to test baroreflex sensitivity. Exercise training significantly decreased baseline renal sympathetic nerve activity (65.8+/-5.2% to 41.3+/-3.9% of Max [where "Max" is the maximum renal sympathetic nerve activity induced by a 50-mL puff of smoke directed to the external nares of the rabbit], P<0.05) and increased the maximal gain of the baroreflex curves for heart rate (2.2+/-0.2 to 4.6+/-0.7 bpm per mm Hg, P<0.01) and renal sympathetic nerve activity (1.9+/-0.2% to 4.5+/-0.4% of Max per mm Hg, P<0.01) in CHF rabbits. Exercise training increased expression of CuZn superoxide dismutase (0.3+/-0.1 to 1.5+/-0.3 [ratio of CuZn superoxide dismutase to tubulin], P<0.01) and decreased NAD(P)H oxidase subunit gp91(phox) protein expression (1.9+/-0.2 to 1.2+/-0.1 [ratio of gp91(phox) to tubulin], P<0.05) in the rostral ventrolateral medulla of CHF rabbits. Central overexpression of CuZn superoxide dismutase dose-dependently decreased baseline renal sympathetic nerve activity (control, 68.5+/-7.1% of Max; 10(10) particles of adenovirus, 53.2+/-4.4% of Max; and 10(11) particles of adenovirus, 33.7+/-3.5% of Max; P<0.05) in CHF rabbits.

CONCLUSIONS

These results suggest that an upregulation in central antioxidative mechanisms and suppressed central prooxidant mechanisms may contribute to the exercise training-induced beneficial effects on autonomic activity in CHF.

Exercise therapy for elderly heart failure patients

Exercise intolerance is one of the hallmark symptoms of heart failure (HF). Exercise training in this condition was not explored as a therapeutic modality until the past two decades. In fact, bed rest was promoted as a treatment for certain forms of HF in the 1970s. Over the past two decades, however, data have shown convincingly that exercise training can be implemented safely in patients who have HF, with significant improvement in functional capacity, various other physiologic variables, and quality of life. This article reviews the accumulated literature in this area, with specific emphasis on the effects of exercise training in older patients who have HF, a subset that may have the most to gain from such training.

Effect of physical training on exercise capacity, gas exchange and N-terminal pro-brain natriuretic peptide levels in patients with chronic heart failure

BACKGROUND

Decreased exercise capacity is the main factor restricting the daily life of patients with chronic heart failure. N-terminal pro-brain natriuretic peptide (NT pro-BNP) is strongly related to the severity of and is an independent predictor of outcome in chronic heart failure.

DESIGN

The study aimed to evaluate the effect of exercise training on functional capacity and on changes in NT pro-BNP levels and to assess the effect of exercise training on quality of life.

MATERIALS AND METHODS

Sixty patients (45 men/15 women, mean age 52.7 years; +/-5.3 SD), with stable heart failure (45 ischaemic/hypertensive and 15 idiopathic patients), in New York Heart Association (NYHA) functional class II (n=35) to III (n=25), with an ejection fraction less than 40%, were randomly assigned to a training (n=30) and a control group (n=30). The training group (30 patients) performed 3 months of supervised physical training programme using a bicycle ergometer for 30 min three times a week at a load corresponding to 60-70% of their oxygen consumption (VO2) peak. The control group did not change their previous physical activity. A graded maximal exercise test with respiratory gas analysis and an endurance test with constant workload corresponding to 85% of the peak oxygen load at the baseline and after 3 months were performed, and at the same times NT pro-BNP levels were measured.

RESULTS

The exercise capacity increased from 15.8 (+/-2.3 SD) to 29.9 (+/-2.1 SD) min (P<0.0001) and the peak VO2 tended to improve from 14.5 (+/-1.4 SD) to 17.7 (+/-2.6 SD) ml/kg per min (P<0.0001) during the supervised training period. VO2 at the anaerobic threshold increased from 12.9 (+/-1.0 SD) to 15.5 (+/-1.7 SD) ml/kg per min (P<0.0001). NT pro-BNP levels decreased from 3376 (+/-3133 SD) to 1434 (+/-1673 SD) pg/ml (P=0.043). The positive training effects were associated with an improvement in the NYHA functional class.

CONCLUSION

Physical training of moderate intensity significantly improves the exercise capacity and neurohormonal modulation in patients with chronic heart failure. This is associated with an alleviation of symptoms and improvement in quality of life.

Cardiac Rehabilitation: A Comprehensive Program for the Management of Heart Failure

Heart failure is one of the major health problems found in the United States today. Medical and interventional therapies play an important role in the treatment of this chronic condition, but they create a huge economic burden on the health care system. Nonpharmacologic interventions need further exploration. This article reviews research that examined the relationship between exercise and heart failure. A variety of exercise modalities measured outcomes of functional capacity and quality of life in both supervised and nonsupervised settings. Many investigators found exercise training to be safe and to confer benefits, especially on functional capacity, quality of life, and survival. The most favorable outcomes were observed in supervised settings. Cardiac rehabilitation provides an ideal environment for safe exercise and management of the health care needs of patients with heart failure. The multidisciplinary staff is adept at providing a paced approach to activity based on individualized exercise prescriptions, education, and management of this population's many comorbidities.

Improved exercise tolerance and cardiac function in severe chronic heart failure patients undergoing a supervised exercise program

BACKGROUND

Exercise intolerance is a widespread and serious problem in chronic heart failure (CHF) patients. However, the impact of a supervised exercise and rehabilitation program on exercise tolerance and cardiac performance in severe CHF patients has not yet been fully investigated.

METHODS

Of 56 consecutive patients with severe CHF (New York Heart Association functional class III, Stage D) 44 underwent a hospital-based supervised 18-week, cardiac exercise and rehabilitation program (exercise group), and 12 did not (control group). Cardiac performance was assessed by a 6-minute walk test, peak exercise VO(2), exercise duration time, resting and immediate post peak exercise stroke index (SI), cardiac index (CI) and systemic vascular resistance (SVR), before and after exercise.

RESULTS

Both groups were comparable regarding baseline clinical characteristics. Post exercise training, functional and hemodynamic parameters improved significantly in the exercise group compared to controls. A highly significant interaction between the groups and change was found in the 6-minute walk test (p<0.001), exercise test duration (p<0.001), METs during exercise (p<0.001), immediate post peak exercise CI (0.016), delta peak VO(2) (p=0.028), and immediate post peak exercise SVR (p=0.045).

CONCLUSIONS

A hospital-based supervised exercise and rehabilitation program significantly improves functional and hemodynamic parameters in severe CHF patients, and may partially contribute to better physical conditioning detected in these patients after exercise training.

Safety and Efficacy of Resistance Training in Patients With Chronic Heart Failure: Research‐Based Evidence

Although a rich body of research exists regarding the safety and efficacy of resistance training, health care providers continue to caution patients with heart failure not to engage in this type of exercise. Research studies utilizing resistance training demonstrate improvements in muscular strength and endurance, New York Heart Association functional class, and quality of life. Despite the hemodynamic changes which occur during resistance exercise, no negative outcomes have been reported. The purpose of this paper is to review the most current research regarding the use of resistance training with heart failure patients to provide assistance to clinicians and enable them to provide education and appropriate recommendations to their patients.

Long-term versus intermediate-term supervised exercise training in advanced heart failure: Effects on exercise tolerance and mortality

AIM

To date there have been no studies exploring the effects of long-term versus intermediate-term and short-term supervised exercise training program in patients with severe chronic heart failure (CHF) on optimal medical therapy. We assessed exercise tolerance and mortality in CHF patients undergoing long- versus intermediate-term exercise training (ET).

METHODS

Forty-two consecutive severe CHF patients (New York Heart Association functional class III) were referred for a supervised exercise and cardiac rehabilitation program and were followed-up for 3 years: 20/42 (48%) patients discontinued ET after intermediate-term period of 1.6+/-0.8 years (Group A, intermediate-term ET), and 22/42 (52%) remained on the ET program for 3.0+/-0.3 years (Group B, long-term ET). Exercise duration, 6-min walked distance and metabolic equivalents (METs) assessed by modified Bruce protocol were recorded before, 4.5 months after, and 3 years after initiation of ET.

RESULTS

Both groups were comparable regarding age, gender, prevalence of ischemic etiology, mean ejection fraction and medications. Risk factors for ischemic heart disease were similar, except for the prevalence of diabetes, which was higher in Group A compared to Group B (11/20 versus 5/22, p=0.03). Significantly more Group A patients died after ET discontinuation (4/20 versus 0/22, p=0.01). At the end of follow-up a significant improvement could be seen in Group B patients compared to A in exercise duration, 6-min walked distance and metabolic equivalents (p<0.01 for all).

CONCLUSIONS

Higher survival rate was observed in severe CHF patients undergoing long-term versus intermediate-term exercise training. Long-term supervised exercise training is safe and improves exercise tolerance in these patients.

Non-Pharmacological Interventions in Older People with Heart Failure: Effects of Exercise Training and Relaxation Therapy

BACKGROUND

Effective management of heart failure relies on optimal use of non-pharmacological therapy alongside medical treatment. Yet, there is an inadequate use of non-pharmacological therapy in caring for older people with heart failure.

OBJECTIVE

To examine the effects of relaxation therapy and exercise training on psychological outcomes and disease-specific quality of life of older heart failure patients.

METHODS

Subjects undertook relaxation (n = 59), exercise training (n = 32) or received attention placebo (n = 62) for 12 weeks. The relaxation group attended two training sessions, one revision workshop, and continued with twice-daily taped-directed home relaxation practice, with support from the intervener through bi-weekly telephone contact, for 12 weeks. The exercise group undertook 12 weekly sessions of resistance training and aerobic exercise and thrice weekly home exercise. The control group received regular telephone calls for general 'greetings'.

RESULTS

The relaxation and exercise groups reported a significantly greater improvement in psychological [F(2, 149) = 6.69, p = 0.002] and various disease-specific quality of life outcomes [dyspnea: F(2, 149) = 5.72, p = 0.004; fatigue: F(2, 149) = 3.78, p = 0.25; emotion: F(2, 149) = 6.68, p = 0.001], compared with those who received the attention placebo. While relaxation therapy was more effective to reduce psychological distress, with depression in particular (p < 0.001), exercise therapy worked better to control fatigue symptoms (p = 0.03).

CONCLUSION

Relaxation therapy and exercise training are effective to improve the psychological and physical health of older heart failure patients. They should be used as an individual treatment modality, or as care components of a disease management program.

Exercise and the heart failure patient: aerobic vs strength training--is there a need for both?

Heart failure (HF) is characterized by general muscular weakness, muscle atrophy, and exercise intolerance that lead to reductions in functional capacity, ability to perform activities of daily living, and health-related quality of life. Until recently, exercise programs for patients with HF were centered on aerobic exercise training alone. Although many activities of daily living require significant muscle strength, the role of strength training for HF patients, either alone or in combination with aerobic exercise, has not been well studied. There is suggestive evidence that combined strength-aerobic exercise training may offer additional benefits in terms of health-related quality of life and functional capacity. Strength training can be targeted to reduce muscle atrophy to a greater extent than aerobic training. Further research is required to isolate the specific role of strength training regarding improvements in prognosis, HF-related morbidity and hospitalization, and health-related quality of life for patients with HF.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

The role of exercise therapy in the treatment of patients with systolic heart failure

The predominant benefits of exercise training in systolic heart failure have been seen with aerobic training, although some information exists for the beneficial effects of resistive training as well. Although men clearly benefit from exercise training, the effects of exercise in women are less clear. Most of the studies have used supervised training 3 to 5 days a week for 8 weeks to 6 months, with 30 to 60 minutes of exercise per session. However, home exercise has been reported in a few studies, and appears to be safe and possibly efficacious. The effects of training on mortality are unknown at this time, although no study has demonstrated increased adverse events associated with training. Exercise training should be recommended for patients with stable New York Heart Association class II to III heart failure.