Effects of exercise interventions on executive function in old adults with mild cognitive impairment: A systematic review and meta-analysis of randomized controlled trials

Aims: To assess the effect of exercise interventions on subdomains of executive function (EF) in older adults with mild cognitive impairment (MCI).Methods: Nine electronic databases were comprehensively searched from their inception to February 2021. Randomized controlled trials examining the effect of exercise training on EF in MCI were included. Results: Twenty-four eligible articles involving 2278 participants were identified. The results showed that ex-ercise interventions had positive benefits on working memory, switching and inhibition in MCI. Subgroup analysis based on exercise prescriptions revealed that both aerobatic exercise and mind-body exercise had similar positive effect size on working memory. However, only mind-body exercise had significant effect on switching. Exercise training with moderate frequency (3-4 times/week) had larger effect size than low frequency (1-2 times/week) and only moderate frequency had positive benefits on switching. Both short (4-12 weeks), medium (13-24 weeks) and long (more than 24 weeks) exercise duration significantly ameliorate working memory and switching, however with short duration having slight larger effect sizes than medium and long.Conclusion: Exercise significantly improves three subdomains of EF in MCI, especially mind-body exercise. Ex-ercise training sticking to at least 4 weeks with 3-4 times a week tends to have larger effect size.