recent data have shown that exercise is considered beneficial for heart failure patients in terms of improved mortality and morbidity , quality of life [ 2 , 3 ] , functional capacity , and improved cardiac   and vascular function . characteristics of heart failure patients who participate in community - based prevalence and exercise training studies may be different with the latter likely to be younger and predominantly male [ 1 , 4 , 7 , 8 ] . north american , european , and australian   guidelines on the use of exercise training in heart failure patients have been developed , although subtle differences exist between the various guidelines . subtle differences may also exist in the demographics of heart failure patients with abnormal systolic function ( chf ) and heart failure patients with normal left ventricular ejection fraction ( hfnef ) . chf patients are normally defined as having left ventricular ejection fraction < 50% and impaired diastolic filling , while hfnef patients have a normal ( > 50% ) ejection fraction but impaired diastolic filling . the aims of this work were to review highlighted differences between the demographics of heart failure patients participating in prevalence studies and those completing exercise training studies . moreover demographic data were presented for systolic heart failure patients and those with heart failure with preserved systolic function . this work also aimed to provide a clinical update on the benefits of exercise training in heart failure patients . data relating to exercise training protocols in heart failure patients and subsequent outcomes were reviewed . pub med ( medline ) , medscape , embase , cinahl , and cochrane controlled trials registry were searched up until june 2010 . search terms used were combinations of the terms exercise training , heart failure , left ventricular dysfunction , physical training , resistance training , guidelines , position stands , systematic reviews , meta - analysis , quality of life , functional capacity , mortality , morbidity , cardiac function , heart failure with preserved systolic function , safety , cytokine expression , brain natriuretic peptide , and aerobic exercise . we examined the latest editions of relevant journals that were not yet available on electronic databases . community - based heart failure prevalence studies were also sought to draw comparisons with exercise studies in heart failure patients . outcome measures fell into three categories : demographics , clinical measures , and public health issues . demographics : age and gender of heart failure patients enrolled in community - based prevalence versus exercise training studies . clinical measures : mortality and morbidity rates , functional capacity , quality of life , cardiac function , cytokine , and brain natriuretic peptide ( bnp ) expression in those who did and did not undertake exercise training . public health : number needed to treat , cost - effectiveness , safety , and minimization of adverse events during exercise   training . heart failure patients who participate in exercise training research tend to be younger ( figure 1 ) and twice as likely to be male ( figure 2 ) compared to those heart failure patients studied in prevalence research [ 1 , 12 ] ; the latter appear to provide a better representation of heart failure patients in the community , suggesting exercise studies may be prone to participant selection bias . evidence suggests younger , male heart failure patients are more likely to participate in exercise training due to possible selection bias . 
  data from exercise training studies of heart failure patients   reports chf patients are younger , mean 59  7 years , and more likely to be male ( 79% ) compared to hfnef patients , mean age 65  5 years and 50% male . evidence suggests chf patients participating in exercise training are younger and more likely to be male . a meta - analysis of exercise training programs in heart failure patients ( extramatch ) reported benefits in terms of mortality and hospitalization . a subanalysis of this study revealed the reduction in overall and cardiac mortality and hospitalization appears to be more likely in sicker patients , specifically those with lower left ventricular ejection fraction , new york heart association class iii / iv , ischemic cardio - myopathy , lower peak vo2 , and those over 60 years of age . in terms of these exercise training program characteristics , these mortality benefits appear to be more apparent in those patients that adhere to an exercise training program for 28 weeks or more . all studies included in the extramatch meta - analysis used cycling as the training modality . in comparison the largest ( 2,300 patients ) randomized , controlled study of exercise training in heart failure patients to date , the heart failure action ( hf - action ) study , reported nonsignificant reductions in mortality and hospitalization , especially in those who do not have factors highly prognostic of mortality . specifically , duration of baseline cardiopulmonary exercise testing , left ventricular ejection fraction , beck depression inventory ii score , and history of atrial fibrillation or flutter were identified as highly prognostic of the primary endpoint of all - cause mortality or hospitalization . after adjusting for prognostic hence exercise training was found to reduce the incidence of all - cause mortality or all - cause hospitalization by 11% . the data from extramatch and hf - action appear to contrast one another , while the former showed a mortality benefit that was most obvious in the sickest patients , the latter only showed a mortality benefit once the patients with prognostic symptoms had been removed from the analysis . evidence equivocal for mortality and hospitalization benefits and also whether disease severity predicts which patients may benefit most . meta - analysis reported that heart failure patients can typically expect to improve their functional capacity by 15%17% following exercise training   and this is a powerful predictor of prognosis in this population . peak vo2 values > 13 - 14  ml / kg / min may confer a 50% cardiac mortality reduction , while a 1  ml / kg / min increase may be associated with a 10% lower cardiac mortality . peak vo2 changes appear to be independent of the type of exercise training undertaken , for example , aerobic , intermittent or resistance training . in comparison , the ( hf - action ) study   reported only a 4% improvement in peak vo2 . meta - analysis data was generated from generally smaller , single site studies which often had facilitated good short - term exercise training adherence rates . hf - action trial authors reported poor adherence in the early part of the training program , and the multicentre study design may have affected the magnitude of change in peak vo2 . moreover , the meta - analysis data was generated mainly from short ( <3 month ) duration studies with only two studies > 12 months duration [ 15 , 16 ] , while hf - action reported both 3 month and 12 month data . twelve months is a difficult period to retain patients , due to either attrition , illness , or death , and also maintain exercise adherence in those who do not withdraw from the study . it has been suggested that exercise training studies tend to overestimate the size of change in peak vo2 of exercise training participants , due to variations in patient motivation and the impracticality of blinding exercise training subjects . the more robust design of hf - action may have minimized the overestimation of peak vo2 and therefore changes were smaller , but perhaps more reliable . only one published exercise training study in hfnef has provided functional capacity data to date suggesting the size of the change in peak vo2 may be similar , or even greater , to that seen in chf patients . evidence suggest functional capacity undoubtedly improves , but what is uncertain is the size of change in peak vo2 which is likely to be between 4%15% . 
  in a systematic review of exercise training in heart failure patients , qol assessment was improved in 11 of 16 randomized controlled studies . a more recent meta - analysis of 35 randomized controlled trials , reported that heart failure patients can expect an improvement of nearly 10 points in minnesota living with heart failure questionnaire scores following exercise training . meta - analysis   showed that exercise training improved left ventricular ejection fraction ( lvef ) , end - diastolic volume ( edv ) , and end - systolic volume ( esv ) in patients with heart failure . the weighted mean difference ( wmd ) of lvef was significantly improved after aerobic exercise training ( 9 trials , 538 patients , wmd = 2.59% ; 95% confidence interval ( ci ) 1.44% to 3.74% ) , edv ( 371 patients ; wmd = 11.49  ml ; 95% ci 19.95 to 3.02  ml ) , and esv ( 371 patients ; wmd = 12.87  ml ; 95% ci 17.80 to 7.93  ml . the authors concluded that aerobic training , but not combined aerobic and strength training , or isolated strength training reverse lv remodelling in clinically stable individuals with heart failure . other data suggest that high intensity ( 95% peak heart rate ) aerobic interval walking will confer even greater improvements in systolic function ( baseline lvef 28% , posttraining lvef 38% ) . evidence suggests exercise training will improve systolic function and should be predominantly aerobic , and if tolerated , intermittent high intensity , in nature as this will convey the greatest improvements in systolic function . 
  published randomized , controlled trials of exercise training in heart failure patients with outcome measures of diastolic function , assessed by tissue doppler have reported variable results . the work of belardinelli   showed improvements in isovolumic relaxation time ( ms ) , early and late diastolic filling in a 2-month exercise training study of heart failure patients with moderate - severe systolic function . similarly improved left ventricular diastolic stiffness   and reduced filling pressure ( e / ea ratio )   in heart failure patients has been reported in two other randomized , controlled trials of exercise training . several small randomized controlled trials have conducted analyses of the effect of different forms of exercise training ( high versus low intensity , cycling versus electrical stimulation , or respiratory muscle training ) on serum measures of proinflammatory cytokines in patients with congestive heart failure . interleukin-6 ( il-6 ) and tumour necrosis factor - alpha are the two most commonly studied proinflammatory cytokines [ 2027 ] . a recent , elegant review clarified the role of il-6 as a fuel ( glucose ) sensor . as glucose metabolism may be affected in heart failure patients , especially during exercise pederson 's review may explain some of the varied effects of exercise training on il-6 . bnp levels are also raised in the circulation of patients with chronic heart failure ( chf ) and may be related to disease severity or poor management . b - type natriuretic peptide ( bnp ) is a cardiac neurohormone released as pre - pro - bnp and then enzymatically cleaved to n - terminal - probnp and bnp upon ventricular myocyte stretch . blood measurements of bnp have been used to identify patients with heart failure [ 29 , 30 ] . currently , bnp assay is used as a diagnostic and prognostic aid in congestive heart failure . in general , a bnp level < 100  pg / ml excludes acutely decompensated heart failure . a recent systematic review in order to establish whether exercise training of chf patients has an effect on circulating bnp levels . meta - analysis of randomized , controlled trials showed that exercise training had a favourable effect on bnp 79  pg / ml 95% c.i . ( 141 to 17 ) p = .01 and nt - probnp 621  pg / ml 95% c.i . two of the included studies had low weekly energy expenditure ( < 400  kcal / week ) and changes in bnp and nt - pro - bnp were not significant in these studies [ 32 , 33 ] . patients who did not undergo training showed no changes , suggesting blunting of adrenergic overactivity and of natriuretic peptide overexpression . evidence unequivocal that b - type natriuretic peptides are reduced following exercise training , moreover a minimum weekly energy expenditure ( circa 400  kcalweek ) may be required to elicit changes in b - type natriuretic peptides . a summary of clinical markers of heart failure prognosis can be seen in figure 3 . as peak vo2 is a strong predictor of prognosis   and heart failure patients undertaking exercise training may expect a 4%15% improvement in peak vo2 . an associated mortality benefit has been reported [ 1 , 15 ] , although hf - action data suggest these benefits remain equivocal . a systematic review calculated the number of heart failure patients that need to undertake exercise training in order to prevent one death is 17 over two years . evidence suggests that 34 heart failure patients need to be provided with exercise training for 12 months to prevent one death from exercise training over this period . table 1 describes the estimated cost - effectiveness of three therapies for heart failure . to highlight the example the cost has been calculated for conducting a heart failure specific exercise program in australia ( in mid-2010 ) , in both a supervised hospital setting and home - based setting ( table 1 ) . a salary of aus$ 60  k p.a . for a full - time graduate exercise physiologist is typical , and would be required to manage 34 patients , however start - up equipment costs of aus$ 510  k have not been included in the estimation as these and other ongoing costs have been excluded . a home exercise program may require only 1 day per week of the same exercise physiologist to telephone patients to verify progress , but little or no equipment  the next section addresses home exercise in more detail . we have used examples cited on the university of toronto 's evidence - based medicine website   of trials of a beta-1 selective blocker   and the diuretic aldactone . when we compare treatment costs to prevent mortality in one patient , we can see that hospital - based exercise is comparable in cost to beta - blockade but noticeably less cost - effective than aldactone , while home exercise training is clearly more cost - effective than beta - blockade but not aldactone . evidence suggests exercise training , especially home - based , is a cost effective adjunct treatment . while both exercise training and the heart failure condition each convey an increased risk of sudden death or adverse event , the published works in this field are yet to identify as single death that could be directly linked to exercise exertion in over 100,00 patient - hours of exercise training . for this reason data from the hf - action trial were zero deaths per 1,000 exercise tests and 0.45 nonfatal major cv events per 1,000 exercise tests ( 95% ci 0.111.81 ) . recent data suggest that although , sudden cardiac death ( scd ) and cardiac events are more prevalent in the morning hours , data do not exist to suggest the time of day exercise training is conducted may not increase the risk of scd or other adverse events . supervised outpatient trials may proffer better adherence rates than home exercise , possibly due to poor motivation and concerns about safety . strategies that improve home exercise compliance require regular patient contact and methods of verifying patient adherence . nevertheless it is possible to sustain peak vo2 and quality of life ( qol ) in a  home a recent systematic review reported that home exercise for heart failure patients may elicit similar magnitude of change in peak vo2 compared to hospital based programs , although some of the data was generated from combined hospital and home exercise studies . periodic measurement of functional capacity , either directly or indirectly may protect against under- or overestimating the optimal training intensity . evidence suggests exercise training is safe for heart failure patients , but home exercise is most beneficial when it follows a supervised , hospital - based program . a summary of public health issues related to heart failure exercise training can be seen in figure 4 . prior to the 1990 's the advice almost unequivocally given to heart failure patients was to avoid physical exertion . a handful of studies prior to the 1990 's suggested exercise training was safe and possibly beneficial in reducing dyspnea and improving mood . in the 1990 's and 2000 's numerous studies and several meta - analyses have highlighted the importance of regular physical activity in improving not only improving physical fitness and quality of life , but also cardiac and blood vessel function and systemic inflammatory and neurohormonal markers of heart failure . moreover exercise appears to be safe and most people with heart failure , with the exception of new york heart association class iv and some other high risk - heart failure patient categories , should be advised to regularly exercise . the change in consensus of opinion towards safety and efficacy of exercise training was based upon data synthesis from many small- to medium - sized trials . notably , meta - analysis   had suggested significant mortality and hospitalization benefits could be derived from exercise training heart failure patients , however closer analysis of the data suggested statistical significance of mortality and hospitalization was absent if the study of belardinelli   was removed from the meta - analysis . then , in late 2008 data was released from the hf - action study   the largest ( 2,300 patients ) exercise training study of heart failure patients to date . hf - action reported nonsignificant reductions in mortality and hospitalization . after adjusting for highly prognostic predictors , exercise training was associated with modest significant reductions for both mortality and heart failure hospitalization . these findings together with the cost and efficacy data presented in this paper suggest exercise has a beneficial role in the nonpharmacological management of heart failure . differences exist in the demographics of participants of prevalence and exercise training studies in heart failure patients . evidence shows exercise training - induced improvements are possible in many indicators of heart failure patient prognosis ; functional capacity , quality of life , systolic and diastolic function , bnp and nt - pro - bnp expression . nevertheless it remains questionable whether exercise training reduces cardiac deaths and hospitalisation and whether disease severity predicts which patients are most likely to benefit .
significant benefits can be derived by heart failure patients from exercise training . 
 this paper provides an evidence - based assessment of expected clinical benefits of exercise training for heart failure patients . 
 meta - analyses and randomized , controlled trials of exercise training in heart failure patients were reviewed from a search of pubmed , cochrane controlled trial registry ( cctr ) , cinahl , and embase . 
 exercise training improves functional capacity , quality of life , hospitalization , and systolic and diastolic function in heart failure patients . 
 heart failure patients with preserved systolic function ( hfnef ) participating in exercise training studies are more likely to be women and are 57 years older than their systolic heart failure ( chf ) counterparts . 
 all patients exhibit low functional capacities , although in hfnef patients this may be age related , therefore subtle differences in exercise prescriptions are required 
 . published works report that exercise training is beneficial for heart failure patients with and without systolic dysfunction .