## 1 Introduction  
The goal of this paper is to study the effect of 6 months of exercise on cognitive-motor integration compared to usual care in \(n=42\) PWD at two residential care facilities. Participants completed single- and dual-task standing (30 s of standing while counting backward by 1 s), walking (4 m walk while naming words), and timed-up-and-go (TUG) tests (TUG with a category task), measured using APDM inertial sensors at baseline and 6 months (age = 82 years, 35% female, Montreal Cognitive Assessment = 10.2 \(\pm\) 5.9, NCT05488951). The adapted Otago Exercise Program involved 60 min of lower-body strength and balance exercises and walking 3x/week for 6 months. Usual care involved regular social activities and healthcare appointments. Exercise provoked increased single-task stride length and increased dual-task TUG turn velocity compared to usual care (\(p<0.05\)). Usual care may reduce the ability to appropriately select cautious gait, as the usual care group exhibited faster dual-task gait speed at 6 months compared to the OEP plus usual care (\(p<0.05\)), which was faster than their single-task gait speed. Our results support implementing the OEP to improve cognitive-motor integration in PWD. **Keywords:** dementia; exercise; dual-task; cognition; posture; gait; randomized controlled trial; clinical trial  
## 1 Introduction  
Dementia is defined as cognitive decline significant enough to impair activities of daily living [1]. There are over 55 million people living with dementia (PWD) worldwide [2]. PWD have twice the risk of falling [3], which could be partly due to simultaneous impairments in dual-task cognition and mobility [4]. Cognitive-motor interference occurs when concurrently performing a cognitive and a motor task (dual-task) that results in a decline in performance on one or both tasks, relative to the performance of each task separately (single-task performance) [5]. Theoretical models postulate that cognitive-motor impairments could stem from a competition for attentional resources (e.g., central capacity sharing model, bottleneck theory) and/or a competition for shared information-processing neural pathways [6]. Typically, PWD observe greater cognitive-motor interference compared to those without dementia, with dual-tasks often performed serially rather than simultaneously [7], thereby impacting functional independence and fall risk [4]. This cognitive-motor impairment is likely a function of deteriorated neural network mapping and white matter integrity in PWD [8]. Cognitive-motor interference has been linked to falls in those with cognitive impairment [9]. Promising interventions targeting cognitive-motor integration have been shown to strengthen vulnerable brain networks in individuals at risk for developing dementia [10]. However, advancements in care-targeted improvements in cognitive-motor integration are needed for those with a diagnosis of dementia. Exercise has been shown to improve dual-task mobility in those without dementia [11; 12; 13]. However, therapeutic intervention advancements in PWD have been limited because PWD have been historically excluded from research due to researchers' eligibility criteria [14]. Exercising may be a viable strategy to improve cognitive-motor integration and functional mobility, but the evidence is mixed. Exercise seems to have a small but meaningful improvement in global cognition [15]; however, the effects of exercise on executive function appear to be unclear, with one meta-analysis showing no effect [15] and another revealing a small, meaningful effect among PWD [16]. One meta-analysis found that the type of exercise did not moderate the effect on cognition [15], while another meta-analysis found that resistance exercise drove improvements in cognition [16]. While multimodal exercise appears to improve activities of daily living, it does not affect muscular strength, posture, or mobility in PWD; however, the strength of the evidence was low to moderate [17].