Are more exercise components in combined cognitive and physical training better for older adults?: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND: Age-related cognitive problems are becoming increasingly prevalent in older adults; thus, maintaining normal cognitive abilities and delaying cognitive decline are essential for promoting healthy aging. METHODS: This systematic review and network meta-analysis examined the effects of combining cognitive and physical training by including various exercise components to improve memory and executive function in older adults. The Cochrane Risk Assessment Tool was used to assess the risk of bias in the included literature. Pairwise meta-analysis was conducted using RevMan 5.3, while network meta-analysis was performed with Stata 15.1, and interventions were ranked based on the results. RESULTS: A total of 8180 articles were screened, and 16 randomized controlled trials were included. Pairwise meta-analysis showed that cognitive-physical interventions with 2 (SMD = 0.26, 95% CI: 0.07-0.44, P = .007) and 3 or more exercise components (SMD = 0.43, 95% CI: 0.13-0.73, P = .004) significantly improved memory compared to controls. For executive function, both interventions with 2 (SMD = 0.40, 95% CI: 0.15-0.65, P = .002) and 3 or more exercise components (SMD = 0.55, 95% CI: 0.16-0.93, P = .005) outperformed the control group. Network meta-analysis confirmed that interventions with 2 (SMD = 0.24, 95% CI: 0.06-0.42) and 3 or more components (SMD = 0.43, 95% CI: 0.13-0.73) improved memory, while a single exercise component was most effective for executive function (SMD = 1.27, 95% CI: 0.05-2.49). Overall, we demonstrated that combined cognitive-physical intervention training with multiple exercise components significantly improved memory and executive function compared to controls. The effects of combined training with 3 or more exercise components were likely the most effective in improving memory. CONCLUSION: Cognitive-physical combined interventions are increasingly applied in clinical research on age-related cognitive decline. Our meta-analysis indicates that interventions incorporating multiple exercise components are more effective than those with a single exercise component. These findings provide a basis for future cognitive and physical interventions for older adults and can inform the design of effective intervention programs.