BACKGROUND: From previous systematic reviews and meta-analyses there is consensus about the positive effect of exercise training on exercise capacity; however, the effects on health-related quality of life, mortality and hospital admissions in heart failure remain uncertain. OBJECTIVES: To update the previous systematic review which determined the effectiveness of exercise-based interventions on the mortality, hospitalisation admissions, morbidity and health-related quality of life for patients with systolic heart failure. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4). To update searches from the previous review, MEDLINE, EMBASE, CINAHL, and PsycINFO were searched (2001 to January 2008). ISI Proceedings and bibliographies of identified reviews were checked. SELECTION CRITERIA: Randomised controlled trials of exercise-based interventions with six months follow up or longer compared to usual medical care or placebo. The study population comprised adults of all ages (> 18 years) with evidence of chronic systolic heart failure. DATA COLLECTION AND ANALYSIS: All identified references were independently screened by two review authors and those that were clearly ineligible were rejected. Full papers of potentially relevant trials were obtained. Data were independantly extracted from the included trials and their risk of bias assessed by a single review author and checked by a second. MAIN RESULTS: Nineteen trials (3647 participants) met the inclusion criteria. One large trial recuited 2331 of the participants. There was no significant difference in pooled mortality between groups in the 13 trials with < 1 year follow up. There was evidence of a non-significant trend toward a reduction in pooled mortality with exercise in the four trials with > 1 year follow up. A reduction in the hospitalisation rate was demonstrated with exercise training programmes. Hospitalisations due to systolic heart failure were reduced with exercise and there was a significant improvement in health-related quality of life (HRQoL). The effect of cardiac exercise training on total mortality and HRQoL were independent of the degree of left ventricular dysfunction, type of cardiac rehabilitation, dose of exercise intervention, length of follow up, trial quality, and trial publication date. AUTHORS' CONCLUSIONS: The previous version of this review showed that exercise training improved exercise capacity in the short term in patients with mild to moderate heart failure when compared to usual care. This updated review provides evidence that in a similar population of patients, exercise does not increase the risk of all-cause mortality and may reduce heart failure-related hospital admissions. Exercise training may offer important improvements in patients' health-related quality of life.