To determine the effects of dual-task aerobic exercise training on community dwelling older adults with early signs of cognitive impairment. We will compare an exercise intervention (E-I) versus an exercise control (E-C) group. Each week, both groups will accumulate a minimum of 120 minutes of exercise (target 150 minutes) from community-based group classes (50 minutes of aerobic exercise) and also complete 45 minutes of beginner-level Square Stepping Exercise (SSE). The E-I group will also answer cognitively challenging questions while doing SSE (dual-task training). This study will determine whether a combined multiple modality (primary component being aerobic exercise) and dual-task exercise program is both feasible and effective for improving cognitive and mobility status, as well as vascular compliance, in older adults who may be at risk for cognitive and mobility decline.