Effects of aerobic exercise and computer-based cognitive training on cognition, functional independence, quality of life, and salivary cortisol levels in older adults with mild cognitive impairment: a randomized trial

Background Mild Cognitive Impairment (MCI) represents an intermediate stage between normal aging and dementia, characterized by measurable cognitive decline without significant loss of functional independence. Non-pharmacological interventions, particularly aerobic exercise and cognitive training, have demonstrated potential benefits; however, their combined effects and underlying neurobiological mechanisms remain inadequately explored. Objective To investigate the effects of aerobic exercise combined with computer-based cognitive training on cognitive function, functional independence, health-related quality of life, and salivary cortisol levels in older adults with MCI. Methods This assessor-blinded, two-arm randomized controlled trial included 60 older adults (60–85 years) diagnosed with MCI. Participants were randomized to either an intervention group receiving aerobic exercise plus computer-based cognitive training ( n = 28) or an active comparison group receiving aerobic exercise with conventional cognitive training ( n = 28). Interventions were delivered over 12 weeks, with assessments conducted at baseline, post-intervention (12 weeks), and follow-up (16 weeks). Primary and secondary outcomes included the Montreal Cognitive Assessment (MOCA), Barthel Index (BI), Short Form-12 (SF-12), and salivary cortisol levels. Data were analyzed using repeated measures ANOVA and Pearson correlation analysis. Results Both groups demonstrated significant within-group improvements in cognitive function, functional independence, quality of life, and cortisol levels over time ( p < 0.05). The intervention group showed significantly greater improvement in MOCA scores at 16-weeks ( p < 0.05). Salivary cortisol levels differed significantly between groups at 12 weeks ( p < 0.05). A significant negative correlation between cortisol levels and cognitive performance was observed at follow-up in both groups. Conclusion Combining aerobic exercise with cognitive training improves clinical outcomes in older adults with MCI and may influence stress-related neurobiological pathways. This multimodal approach represents a promising, non-pharmacological strategy for mitigating age-related cognitive decline.