Physical exercise improves working memory (WM) across the lifespan, yet the neural mechanisms underlying this benefit remain incompletely understood, and it is unclear whether intervention-induced neuroplastic changes and long-term exercise-related differences converge on common neural circuits. We systematically searched PubMed, Web of Science, PsycINFO, and CNKI through June 2026 and included 11 task-based fMRI studies (6 longitudinal interventions and 5 cross-sectional comparisons; 403 par-ticipants) reporting whole-brain activation coordinates. Activation likelihood estima-tion (ALE) meta-analyses were performed separately for activation increases and de-creases within each design. Longitudinal studies revealed exercise-induced activation increases in the bilateral cerebellum (posterior lobe, cerebellar tonsil) and decreases in the right thalamus. Cross-sectional studies revealed greater activation in the left middle temporal gyrus (BA 21) and reduced activation in the right cingulate gyrus (BA 24) and left caudate body among long-term exercisers relative to controls. Critically, the two designs yielded spatially non-overlapping patterns. These findings support a du-al-mechanism model in which exercise strengthens task-positive network engagement while optimizing the suppression of task-irrelevant processing, and they suggest that exercise shapes working memory circuitry across distinct, timescale-dependent neural circuits.