The Impact of Aerobic Exercise on Fronto-Parietal Network Connectivity and Its Relation to Mobility: An Exploratory Analysis of a 6-Month Randomized Controlled Trial

Abstract

Impaired mobility is a major concern for older adults and has significant consequences. While the widely accepted belief is that improved physical function underlies the effectiveness of targeted exercise training in improving mobility and reducing falls, recent evidence suggests cognitive and neural benefits gained through exercise may also play an important role in promoting mobility. However, the underlying neural mechanisms of this relationship are currently unclear. Thus, we hypothesize that 6 months of progressive aerobic exercise training would alter frontoparietal network (FPN) connectivity during a motor task among older adults with mild subcortical ischemic vascular cognitive impairment (SIVCI)—and exercise-induced changes in FPN connectivity would correlate with changes in mobility. We focused on the FPN as it is involved in top-down attentional control as well as motor planning and motor execution. Participants were randomized either to usual-care (CON), which included monthly educational materials about VCI and healthy diet; or thrice-weekly aerobic training (AT), which was walking outdoors with progressive intensity. Functional magnetic resonance imaging was acquired at baseline and trial completion, where the participants were instructed to perform bilateral finger tapping task. At trial completion, compared with AT, CON showed significantly increased FPN connectivity strength during right finger tapping (p < 0.05). Across the participants, reduced FPN connectivity was associated with greater cardiovascular capacity (p = 0.05). In the AT group, reduced FPN connectivity was significantly associated with improved mobility performance, as measured by the Timed-Up-and-Go test (r = 0.67, p = 0.02). These results suggest progressive AT may improve mobility in older adults with SIVCI via maintaining intra-network connectivity of the FPN.

Interventions to Improve Gait in Older Adults with Cognitive Impairment: A Systematic Review

“…Nineteen studies investigated the effect of exercise programs on gait (Table ). All except 2 were RCTs.…”

“…Sample sizes ranged from 16 to 200 and mean age from 69.8 to 88.3, and the majority of participants were female (range 50.0-100%) except 2 studies. 43,51 Participants were recruited from aged care facilities (9 studies), outpatient clinics (5 studies), the community (4 studies), and inpatient rehabilitation (1 study). Participants were diagnosed with dementia, AD (or probable AD), or MCI.…”

Physical exercise increases involvement of motor networks as a compensatory mechanism during a cognitively challenging task

“…[10][11][12][13] Despite these findings, the biological mechanism underlying enhanced cognition through physical exercise training remains to be completely elucidated. [19][20][21] Thus far, we did not find any study investigated whether physical exercise improves cognitive function through increasing neural compensatory ability, one of manifestation of cognitive reserve. [19][20][21] Thus far, we did not find any study investigated whether physical exercise improves cognitive function through increasing neural compensatory ability, one of manifestation of cognitive reserve.…”

“…Previous results revealed direct effects of exercise on the brain through (1) reducing the loss of brain volume in the frontal, prefrontal, and temporal regions (especially in hippocampus) [14][15][16] ; (2) improved neural function, evidenced by increased task-relevant activation in executive and attention network 17,18 ; and (3) improved resting-state functional connectivity and efficiency of functional connectivity in large-scale brain networks related to cognitive function. [19][20][21] Thus far, we did not find any study investigated whether physical exercise improves cognitive function through increasing neural compensatory ability, one of manifestation of cognitive reserve. Our previous findings have identified a positive correlation between physical fitness (measure with gait speed) and neural compensatory ability.…”

Brain–Machine Interface-Driven Post-Stroke Upper-Limb Functional Recovery Correlates With Beta-Band Mediated Cortical Networks

“…Fronto-parietal connectivity is known to be involved in top-down attentional control and visuospatial processing [65]. Recently, its association with mobility has been established through a randomized controlled trial involving aerobic exercise [66]. However, the hemispheric lateralization showed specificity of the intervention effect on the FP network.…”