OBJECTIVE Abnormal expression of cellular adhesion molecules may be related to endothelial dysfunction, a key feature in chronic heart failure. This study compares the effects of 10-wk supervised moderate-intensity continuous aerobic exercise (CAE) and intermittent aerobic exercise (IAE) programs on markers of endothelial damage, disease severity, functional and metabolic status, and quality-of-life in chronic heart failure patients. DESIGN Fifty-seven patients between 41 and 81 yrs with New York Heart Association class II-III chronic heart failure and with a left ventricular ejection fraction of 35%-55% were randomized into three groups: nonexercising control, CAE, and IAE, which exercised three times a week for 10 wks. Endothelial damage was assessed by serum markers of vascular cell adhesion molecule-1, serum intercellular adhesion molecule-1, and nitric oxide; disease severity was measured by left ventricular ejection fraction and N-terminal probrain natriuretic peptide; metabolic status was evaluated by body composition analysis and lipid profile levels; functional status was evaluated by cardiorespiratory exercise stress test and 6-min walking distance; quality-of-life was assessed with Left Ventricular Dysfunction-36 and Short-Form 36 questionnaires at the baseline and at the end of the 10th week. RESULTS Significant decreases in serum vascular cell adhesion molecule-1 or serum intercellular adhesion molecule-1 in IAE and CAE groups after training were found, respectively. Resting systolic and diastolic blood pressure, peak systolic and diastolic blood pressure, 6-min walking distance, and the mental health and vitality components of Short-Form 36 improved in the CAE group, whereas left ventricular ejection fraction and 6-min walking distance improved in the IAE group compared with the control group. CONCLUSIONS Both moderate-intensity CAE and IAE programs significantly reduced serum markers of adhesion molecules and prevented the change in VO2 in patients with chronic heart failure.