Restoring Central Motor Control Extension

Inclusion Criteria: * 65 years of age and older * Ambulatory without an assistive device or the assistance of another person * Usual 4 meter gait speed \> 0.60 m/s and \< 1.2 m/s * Physician clearance to participate in a moderate intensity exercise program * Not meeting physical activity recommendations defined as reporting less than 150 minutes of moderate intensity activity per week in the past month. Exclusion Criteria: * persistent lower extremity pain that is present on most days of the week * back pain that is present on most days of the weeks and interferes with walking and - activities of daily living or back pain that increases with walking * refuse to walk on a treadmill * plans to move out of the area in the next 5 years * dyspnea at rest or during activities of daily living or use supplemental oxygen (CHF, COPD) * any acute illness or medical condition that is not stable according to the approving physician * resting systolic blood pressure ≥ 200 mm Hg or diastolic blood pressure ≥ 100 mm Hg or resting heart rate \> 100 or \< 40 beats per minute * diagnosed dementia or cognitive impairment defined as modified Mini-Mental State (3MS) examination \<79 * hospitalized in the past 6 months for acute illness or surgery, other than minor surgical procedures * severe visual impairment f- ixed or fused lower extremity joints such as hip, knee or ankle * lower extremity strength \<3/5 on manual muscle testing * lower extremity amputation * progressive movement disorder such as Multiple Sclerosis, Amyotrophic Lateral Sclerosis or Parkinson's disease