Inclusion Criteria: - At least 21 years of age - Symptomatic CHF for at least 3 months - Limited exercise tolerance on a treadmill - Reduced left ventricular ejection fraction - Stable heart failure medication - Hemoglobin concentration between 9.0 and 12.5 g/dL Exclusion Criteria: - Hypertension - Unstable angina pectoris or recent myocardial infarction - Likely to receive cardiac transplant - Unable to do cardiopulmonary exercise testing - Major organ transplant (e.g., lung, liver, heart) or in renal replacement therapy (e.g., dialysis) - Recent or current treatment for malignancy - Systemic hematologic disease - Anemia due to acute or chronic bleeding - Recent epogen or darbepoetin alfa therapy - Recent blood transfusion