Effects of multicomponent exercise on global cognitive function, executive function, and brain-derived neurotrophic...

To systematically evaluate the effects of multicomponent exercise on global cognitive function, executive function, and brain-derived neurotrophic factor in older adults with mild cognitive impairment using a three-level meta-analysis.

Web of Science, Cochrane Library, Embase, EBSCOhost, PubMed, CNKI, Wanfang, and Weipu were systematically searched from inception to September 15, 2025, to identify randomized controlled trials (RCTs) examining multicomponent exercise interventions in older adults with mild cognitive impairment. Methodological quality was assessed using the PEDro scale, and the quality of evidence was evaluated using the GRADE system. Meta-analysis was conducted using a three-level random-effects model in R software, and publication bias was examined. Effect sizes were estimated using Hedges' g with 95% confidence intervals (CIs), and 95% prediction intervals (PIs) were calculated to determine the expected range of effect sizes in future comparable studies. Funnel plots and Egger's regression test were used to assess publication bias.

A total of 10 RCTs comprising 623 older adults with MCI from community settings, hospitals, and nursing homes were included. The interventions consisted primarily of multicomponent exercise at moderate intensity, with session durations of 30-90 min, frequencies of 2-5 sessions per week, and intervention periods of 8-48 weeks. Control groups received usual care or health education. Most studies reported no exercise-related adverse events. The mean PEDro score of the included studies was 6.0. The three-level meta-analysis revealed that multicomponent exercise significantly improved global cognitive function (g = 1.063, 95% CI [0.355, 1.771], p = 0.007, 95% PI [-1.141, 3.267]) and executive function (g = 0.372, 95% CI [0.140, 0.604], p = 0.005, 95% PI [0.140, 0.604]) in older adults with MCI. BDNF was assessed in only two studies, with conflicting findings, and its effects remain inconclusive. Exploratory subgroup analyses revealed that none of the moderator variables reached statistical significance: exercise duration [F(1,9) = 0.127, p = 0.730], exercise frequency [F(1,10) = 3.421, p = 0.094], intervention duration [F(1,10) = 0.0002, p = 0.988], and measurement tools [F(2,9) = 0.882, p = 0.447] all showed no significant moderating effects. Owing to the limited number of effect sizes in certain categories (k ≤ 2), interaction tests were not performed for exercise modality, and results across groups were presented descriptively. Descriptive analyses showed that the combinations of "aerobic + strength + balance + coordination + agility" training (k = 2, g = 2.109, 95% CI [0.816, 3.402], p = 0.006) and "aerobic + strength + flexibility" training (k = 2, g = 2.039, 95% CI [0.772, 3.307], p = 0.007) yielded large effect sizes. Interventions with session durations of 30-60 min improved global cognitive function (g = 1.236, 95% CI [0.151, 2.321], p = 0.030), as did those with frequencies of 4-5 sessions per week (g = 1.772, 95% CI [0.714, 2.830], p = 0.004). Assessments using both the MoCA (g = 1.337, 95% CI [0.235, 2.439], p = 0.023) and the MMSE (g = 1.054, 95% CI [0.214, 1.895], p = 0.020) supported the positive effects of multicomponent exercise on global cognition. With respect to executive function subdomains, cognitive flexibility was significantly improved (g = 0.437, 95% CI [0.112, 0.761], p = 0.014), whereas working memory and inhibitory control did not reach statistical significance.

The overall methodological quality of the included studies was moderate; however, most studies did not implement allocation concealment or fully report blinding procedures, indicating a certain risk of bias. Tests for publication bias did not indicate significant bias. GRADE assessment showed that the quality of evidence was low for global cognitive function and moderate for executive function. Multicomponent exercise exerts positive effects on global cognitive function and executive function in older adults with MCI, whereas its effects on BDNF remain inconclusive. Future studies with more rigorous designs and adequate sample sizes are warranted to promote the personalized application of multicomponent exercise in the MCI population.

This study was registered in PROSPERO (No. CRD420251164302; https://www.crd.york.ac.uk/).