PROJECT SUMMARY/ABSTRACT Non-pharmacological interventions, such as physical exercise or movement therapies, to prevent falls in older adults with mild cognitive impairment (MCI) have not been effective. Our long-term goal is to establish a safe and efficacious mind-body exercise intervention that can be made widely available in community settings and for clinical practice to prevent falls in a rapidly growing, at-risk population of community-dwelling older adults with MCI. The objective of this proposal is to evaluate a novel intervention—dual-task Tai Ji Quan: Moving for Better Balance (Dual-TJQMBB)—that is specifically tailored for older adults with MCI to prevent falls. The rationale underlying this proposal is that by integrating cognitive exercises with physical (tai ji quan) movements we address the impaired balance and concomitant attention (dual-tasking) deficits associated with the increased risk of falling in this population. The central hypothesis is that our therapeutically tailored and dual-task augmented tai ji quan training approach will be more efficacious than traditional tai ji quan training in preventing falls. The central hypothesis, with its premise established from our prior work and promising pilot data, will be tested by pursuing our Primary Aim in which we will determine the efficacy of a 6-month Dual- TJQMBB intervention in reducing the incidence of falls among older adults with MCI. We will address our Primary Aim using an innovative e-health (online) intervention delivery approach with a 3-arm, single-blind, randomized controlled trial involving a test of the comparative efficacy of the two tai ji quan fall prevention interventions (Dual-TJQMBB, standard TJQMBB) relative to a stretching control. We hypothesize that, by month 6, participants assigned to the Dual-TJQMBB intervention will show a significant reduction in the incidence of falls (primary outcome) and improvement in dual-task walking and physical and cognitive performances (secondary outcomes) compared to those assigned to the stretching control. The project has two secondary aims: (1) to determine how well the benefits of our Dual-TJQMBB intervention persist over a 6- month post-intervention follow-up, and (2) to examine whether the impact of Dual-TJQMBB training on reducing the incidence of falls is mediated by change in dual-task walking performance. Our proposed research is significant because it will fill a vital gap in clinical practice by providing efficacy evidence about a tailored fall prevention intervention that combines tai ji quan with cognitive task training, for the first time, for older adults with MCI who are at risk of falling and continuing cognitive decline. If the evidence supports the Dual-TJQMBB hypothesis, the proposed study can (a) make a rapid impact on clinical practice guidelines in the field of fall prevention and (b) have a widespread positive impact very quickly because it can be coupled with the standard TJQMBB program, which ...