Effects of cognitive workload during motor-cognitive training on executive function, dual-task performance, and posture control: a RCT among middle-aged and older adults.

BACKGROUND: Falls are a major concern in geriatric health, and impairments in executive function (EF), gait, and postural control are important fall-related risk factors. Interactive motor-cognitive training (IMCT) has shown promise as an intervention to mitigate these risks. This study aims to assess the acute effects of IMCT programs with three levels of cognitive load (high, medium, and low) on EF, spatio-temporal gait parameters, and postural control in middle-aged and older adults. METHODS: In this single-blind, parallel-group randomized controlled trial, 42 participants (58.1 ± 9.9 years) were randomly allocated to a low cognitive load group (LCG), medium cognitive load group (MCG), or high cognitive load group (HCG). Each group completed a 30-min IMCT session using the SpeedCourt system. EF, postural control, and single/dual-task gait performance were assessed before and after the intervention. RESULTS: Multivariate analysis showed significant between-group differences in EF (Pillai V = 0.804, p = 0.015, ηp 2  = 0.402) and gait performance (Pillai V = 1.201, p < 0.001, ηp 2  = 0.601); no significant changes were observed in postural control (Pillai V = 0.543, p = 0.323, ηp 2  = 0.271). The MCG showed greater improvement in Stroop neutral reaction time than the LCG and HCG, while 2-back accuracy improved relatively more in the LCG. The MCG also showed greater improvement in dual-task gait velocity, whereas the LCG showed a greater increase in correct responses during dual-task walking. Discriminant function analysis identified Stroop neutral reaction time, 2-back accuracy, gait velocity, and correct responses as the most sensitive variables. CONCLUSION: A single session of IMCT with different cognitive loads was associated with immediate changes in selected EF and dual-task gait outcomes in middle-aged and older adults. Moderate cognitive load appeared most favorable for processing-speed-related Stroop performance and dual-task gait velocity, whereas low cognitive load was associated with greater gains in dual-task correct responses.