Nonlinear dose-response of mind-body exercise in older adults with mild cognitive impairment: A systematic review and meta-analysis.

OBJECTIVE: This study aimed to quantify domain-specific dose-response relationships between mind-body exercise and cognitive function in older adults with mild cognitive impairment (MCI), and to derive actionable dosing recommendation. METHODS: Eight major electronic databases were systematically searched up to September 15, 2025. Randomized controlled trials (RCTs) of mind-body exercise intervention in individuals aged ≥60 years with MCI that reported at least one cognitive domain outcome were included. Hedges'g effect sizes were calculated using random-effects models, and dose-response relationships were examined using restricted cubic spline regression. RESULTS: Twenty-seven RCTs (2034 participants) were included. Moderate-certainty evidence supported improvements in global cognition (Hedges' g: 0.67, 95% CI: [0.49, 0.78]) and processing speed (0.45 [0.3, 0.6]). Global cognition exhibited a U-shaped weekly dose-response, with 240 min/week as the relative nadir that still yielded a significant pooled effect (0.37; [0.19, 0.55]); longer intervention durations significantly amplified this overall response (β = 0.012, p < 0.05), and achieving significant benefit at this dose required ≥11 weeks intervention. Memory followed a similar pattern, but with very low certainty. Processing speed showed a U-shaped cumulative dose-response (nadir: 3400 minutes), and this effect was attenuated by weekly dose (β = -0.0011, p < 0.05), yet caution is warranted because the weekly doses in the included studies were heavily clustered. CONCLUSIONS: Mind-body exercise produces domain-specific dose-response patterns in older adults with MCI. For global cognition, the observed U-shaped pattern suggests that if 240 min/week dose is adopted clinically, extending intervention to at least 11 weeks is advisable. However, prospective validation of these findings is needed before clinical application.