This randomized clinical trial targets 248 community-dwelling older adults with impaired mobility (i.e. walking slowly; gait speed < 1.20 m/s). The trial compares a 12 week "standard-plus" program of strength, endurance, flexibility plus task specific timing and coordination training to a standard 12 week strength, endurance and flexibility program. The primary outcome is gait speed at 12 weeks. Secondary and tertiary outcomes represent components of the intervention and measures of activity and participation. Delayed and sustained effects of the intervention are examined at 24 and 36 weeks.

Walking difficulty is common and costly in older adults. While traditional exercise has been shown to promote physical and mental health and may prevent walking difficulty, such exercise has focused on strength and endurance, and has overlooked a critical component of walking ability; the timing and coordination of movement. Aging and disease alter timing and coordination as reflected by slowed neuromotor performance, increased gait variability and reduced smoothness of movement. Task specific timing and coordination exercise that includes practice of smooth coordinated aspects of gait over multiple walking conditions has the potential to improve walking ability greater than a standard program. Our preliminary data suggest that interventions on timing and coordination of gait impact mobility greater than the standard strength and endurance program. The next key step and the objective of this proposal is to combine the two interventions to determine if potential gains in mobility, activity and participation obtained from a standard plus timing and coordination program, are larger than the gains obtained from the standard program alone. Therefore, the primary aim of the proposed project is to evaluate the impact of adding timing and coordination training to standard strength and endurance training on mobility. Secondary aims include examining 1) additional outcomes representing the components of the intervention and measures of activity and participation, 2) the delayed and sustained effects of the intervention, and 3) the effects of the intervention within various other subgroups of interest. This randomized clinical trial in 248 community-dwelling older adults who walk slowly (i.e. < 1.20 m/s) will compare a standard 12 week strength, endurance and flexibility program to a 12 week "standard-plus" program of strength, endurance, flexibility plus task specific timing and coordination training. The primary outcome is gait speed at 12 weeks. We will also examine secondary and tertiary outcomes representing components of the intervention and measures of activity and participation and the delayed and sustained effects at 24 and 36 weeks. The findings from this efficacy trial will provide evidence for the added value of task specific timing and coordination training for promoting walking ability in older adults and will form the basis for future effectiveness trials. Future work includes translation to nonprofessional exercise leaders with the long-term goal to incorporate neurological training into standard exercise programs for health promotion for older adults.

Inclusion Criteria:

1. 65 years of age and older
2. Ambulatory without an assistive device or the assistance of another person
3. Usual 4 meter gait speed > 0.60 m/s and < 1.2 m/s
4. Physician clearance to participate in a moderate intensity exercise program
5. Not meeting physical activity recommendations defined as reporting less than 150 minutes of moderate intensity activity per week in the past month.7

Exclusion Criteria:

1. persistent lower extremity pain that is present on most days of the week
2. 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
3. refuse to walk on a treadmill
4. plans to move out of the area in the next 5 years
5. dyspnea at rest or during activities of daily living or use supplemental oxygen (CHF, COPD)
6. any acute illness or medical condition that is not stable according to the approving physician
7. resting systolic blood pressure ≥ 200 mm Hg or diastolic blood pressure ≥ 100 mm Hg or resting heart rate > 100 or < 40 beats per minute
8. diagnosed dementia or cognitive impairment defined as modified Mini-Mental State (3MS) examination <79
9. hospitalized in the past 6 months for acute illness or surgery, other than minor surgical procedures
10. severe visual impairment
11. fixed or fused lower extremity joints such as hip, knee or ankle
12. lower extremity strength <3/5 on manual muscle testing
13. lower extremity amputation
14. progressive movement disorder such as Multiple Sclerosis, Amyotrophic Lateral Sclerosis or Parkinson's disease