The regular effects of concurrent aerobic and resistance exercise on global cognition in healthy elderly populations: A systematic review with meta-analysis of randomized trials

Aerobic and resistance exercises are widely recognized as essential for preserving and enhancing cognitive function. However, the effects of concurrent exercise on cognition in older adults remain unclear. This systematic review sought to evaluate the regular effects of concurrent aerobic and resistance training on global cognition in healthy older adults. A comprehensive search was conducted across PubMed, Web of Science, EMBASE, Google Scholar, Cochrane Library, and CNKI up to July 2024. Randomized controlled trials involving healthy older adults aged >= 65 years that assessed the cognitive effects of concurrent exercise were included. The methodological quality of the included studies was evaluated using the PEDro scale. Meta-analyses were performed using a random-effects model, and heterogeneity was quantified with the 1(2) statistic. The initial search identified 13,533 records, ultimately including 12 studies in the meta-analysis, which involved 2557 participants. The meta-analysis revealed non-significant effects of concurrent exercise on global cognition (SMD = 0.1(2), 95 % CI: -0.08 to 0.33, p = 0.200). The subgroup analysis indicated that concurrent exercise cannot enhance global cognition compared to active controls (SMD = -0.03, 95 % CI: -0.23 to 0.18, p = 0.80), but it does show significant improvement compared to passive controls (SMD = 0.35, 95 % CI: 0.14 to 0.56, p < 0.001). Moderate heterogeneity was observed (1(2) = 49.9 %), and sensitivity analyses confirmed the stability of the results. No significant publication bias was identified. While concurrent exercise was effective in improving global cognition in healthy older adults, the improvements were not superior to active control conditions. Future research should investigate optimal training combinations and sequences to maximize cognitive benefits.