The purpose of this research study is to compare two different exercise treatments for walking problems in older adults. The investigators want to determine if participation in the exercise programs will improve walking and thinking abilities.

Specific Aims We will examine the impact of moderate intensity aerobic and of motor skill exercise interventions on improving gait and cognition in older adults with slow gait and psychomotor slowing. In a thrice weekly, 12 week, randomized clinical trial, we propose the following aims: 1) to define the impact of moderate intensity aerobic and motor skill gait exercise on thinking while walking, and 2) to define the impact of moderate intensity aerobic and motor skill gait exercise on gait and cognition. Brief Background The optimal exercise to improve gait and brain health in older adults is not known. Two types of exercise with potential for affects on gait and brain health, aerobic and motor skill exercise, developed out of distinct disciplines and have been studied separately, but not in older adults with the same age-related, centrally-generated slow gait dysfunction or for their effects on an integrated measure of gait and cognition, 'walking while thinking'. Summary of Methods We propose two parallel, single arm clinical trials to define the impact of aerobic and motor-skill exercise on gait and cognitive functions, in community-dwelling older adults with slow gait and psychomotor slowing, randomly assigned to moderate intensity aerobic gait (n=12) or motor skill gait (n=12) exercise, three times a week, for 12 weeks, in small groups of 2-3 supervised by a physical therapist. Primary outcomes are integrated measures of thinking while walking, with secondary outcomes of specific measures of gait and cognitive function collected pre, 4, 8 and 12 weeks post interventions, to examine impact of exercise and dose-response effects on gait and cognition. Future Use of Data The intent of the proposed pilot is to generate complementary data essential to support an R01 clinical trial grant submission. Specifically in this pilot we will: 1) recruit older adults with both slow gait speed and evidence of psychomotor slowing, 2) explore and define a primary outcome measure that integrates both gait and cognition, and thus better represents the goal of the exercise interventions - thinking while walking, 3) determine potential mean and variability estimates for gait and cognitive outcomes, particularly the less well-characterized gait outcomes of aerobic exercise (energy expenditure for walking, gait variability, gait abnormalities), and cognitive outcomes of motor skill exercise (speed of processing, executive function).

Inclusion Criteria:

• slow gait speed (<= 1.0m/s and >= .6m/s)
• slow cognitive processing (digit symbol substitution < age-adjusted norm
• medical clearance from primary physician for participation in exercise

Exclusion Criteria:

• dementia or Mild Cognitive Impairment MCI
• pain while walking that limits walking
• active medical conditions, not controlled or managed