Effects of exercise on cognitive performance and ERP (P3, N2) in overweight and obese populations: a systematic review and meta-analysis

Individuals with overweight/obesity often show cognitive-control deficits, reflected in slower reaction times, lower accuracy, attenuated P3, and altered N2. We meta-analysed randomized controlled and within-subject crossover studies comparing exercise versus non-exercise controls during standard cognitive-control tasks. Primary outcomes were reaction time (RT), reaction accuracy (RA), P3 amplitude, and N2 amplitude; risk of bias was assessed with Cochrane RoB 2, and ERP reporting was evaluated with a checklist aligned to RoB-2 D4/D5.Across 14 studies, exercise was associated with faster RT and larger P3 amplitude. RA and N2 showed directionally favorable but lower-certainty effects, reflecting substantial heterogeneity, small samples, and limitations in ERP quality reporting (e.g., sparse SNR/QC metrics; infrequent assessor blinding). Exploratory subgroup/meta-regression analyses offered limited explanatory power overall but suggested potential contributions of task paradigm, exercise mode, and design/comparator features-effects appeared larger in Stroop/Flanker than Go/No-Go and tended to be more pronounced for higher-arousal modes and under baseline/assessment-only controls and in designs incorporating baseline assessments-though these patterns should be interpreted cautiously given residual heterogeneity, sparse strata, and multiple comparisons.Exercise thus confers measurable behavioral and electrophysiological gains in individuals with elevated BMI, consistent with cerebral blood-flow/neuroplasticity and catecholaminergic arousal mechanisms. Improved prespecification/multiplicity control and transparent ERP reporting are needed to strengthen future evidence and clarify dose-response and timing effects.