Regular Exercise Moderates Age-Related Cognitive Differences in Midlife Women: Domain-Specific Effects on Processing Speed and Working Memory

OBJECTIVES: This study examined whether regular exercise moderates age-related cognitive differences in midlife women, including reaction time (RT), executive planning, and working memory. We further investigated whether these effects differ across exercise modalities. METHODS: This cross-sectional study included ninety-three women (35-63 years) who completed simple RT, working memory, and executive planning tasks. Participants were categorized by exercise regularity and modality. Time-based outcomes were analyzed via Linear Mixed Models; accuracy via Generalized Estimating Equations. Pairwise comparisons utilized Welch's t-tests with FDR correction. RESULTS: Regular exercise moderated age-related slowing in simple RT (β=-3.083, p=0.032). Resistance training participants exhibited faster RTs than those in the non- regular exerciser, aerobic, and other exercise groups. Regarding working memory, the impact of exercise on response speed was significantly moderated by both age and task difficulty (β = -15.91, p < 0.001). Specifically, exercise-related benefits became more pronounced as cognitive load increased, a trend primarily driven by older participants, whereas these effects were less evident in younger cohorts. However, no modality-specific differences were observed. In contrast, executive planning performance was associated with age, with no significant effects of exercise or exercise-related interactions. CONCLUSIONS: These findings suggest that regular exercise moderates age-related cognitive differences in midlife women, particularly in processing speed and high-demand working memory. These benefits were domain-specific: modality-specific advantages emerged in simple reaction time, whereas working memory benefits were modality-independent. The notable efficacy of resistance training further highlights the importance of exercise modality. Findings identify midlife as a sensitive window for targeted exercise interventions to preserve cognitive health.