Effects of aerobic exercise on executive function of healthy middle-aged and older adults: A systematic review and meta-analysis

The deterioration of executive function is a hallmark of cognitive aging. Reports indicate that signs of decline in executive function begin to emerge as early as middle age. Aerobic exercise improves executive function in healthy middle-aged and older adults, but the optimal exercise prescription variables are still unclear.

To investigate the effects of aerobic exercise on executive function of healthy middle-aged and older adults and explore the dose-response relationship and moderators.

We conducted comprehensive searches of PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, PsycINFO, and SPORTDiscus for English literature, and CNKI, WanFang, and VIP for Chinese literature, covering the period from inception until April 25, 2024. Randomized controlled trials examining the effect of aerobic exercise on executive function in healthy middle-aged and older adults aged 45 or older were included. The Cochrane Collaboration's RoB2 tool was used to assess the methodological quality of the included studies. And subgroup analyses and meta-regressions were conducted to elucidate the impact of aerobic exercise on executive function.

Forty-two eligible randomized controlled trials, involving a total of 2881 participants, met the inclusion criteria for the systematic review and meta-analysis. The pooled results showed that aerobic exercise had positive effects on improving cognitive flexibility (Hedge's g = 0.343, p < 0.001), working memory (Hedge's g = 0.392, p < 0.001), and inhibitory control (Hedge's g = 0.229, p < 0.001) in healthy middle-aged and older adults. However, it did not demonstrate an improvement in planning (Hedge's g = 0.094, p = 0.440). The dose-response relationships between different exercise parameters and subdomains of executive functions revealed that the largest effects on cognitive flexibility were observed after 13-24 weeks of progression-intensity mind-body exercise, 46-60 min per session, and 5-7 days per week. Regarding working memory, the largest effects were observed after 13-24 weeks of progression-intensity general aerobic exercise, 20-45 min per session, and 5-7 days per week. For inhibitory control, the greatest effects were noted after 13-24 weeks of low-intensity general aerobic exercise, 20-45 min per session, and 3-4 days per week.

Aerobic exercise can significantly improve cognitive flexibility, working memory, and inhibitory control in healthy middle-aged and older adults. The effect of aerobic exercise on different aspects of executive function is influenced by specific exercise parameters, suggesting that personalized aerobic exercise programs may be more effective for enhancing executive function of healthy middle-aged and older adults.