Inclusion Criteria- Stroke > 6 months prior with residual hemiparetic gait in women or men aged 40-85 years.
- Completion of all regular post-stroke physical therapy
- Adequate language and neurocognitive function to participate in testing and training and to give adequate informed consent.
- Able to rise from a chair unaided.
- Able to walk 10 meters without human assistance.
Exclusion Criteria- Regular structured aerobic exercise (> 2x week).
- Alcohol consumption > 3 oz. liquor, or 3 x 4 oz glasses of wine, or 3 x 12 oz. beers per day, by self-report.
- Clinical history of
- unstable angina,
- recent (< 3 months) myocardial infarction or congestive heart failure (NYHA category II),
- hemodynamically significant valvular dysfunction,
- Peripheral Arterial Obstructive Disease with claudication,
- major orthopedic, chronic pain, or non-stroke neuromuscular disorders restricting exercise,
- pulmonary or renal failure,
- poorly controlled hypertension (>190/110), measured on at least two separate occasions
- recent hospitalization for severe disease or surgery
- severe or global receptive aphasia which confounds reliable testing and training.
- Untreated major depression as documented by a Center for Epidemiological Studies-Depression score of >16 and confirmed by clinical interview.