Leisure Activities: A Narrative Review of Established Evidence and New Perspectives on the Cognitive Reserve Framework in Healthy Populations Across the Adult Lifespan

Background/Objectives: The concept of Cognitive Reserve (CR) has assumed a central role in research on the prevention of cognitive decline. The term refers to the brain’s capacity to manage age-related changes or pathologies by enhancing neural efficiency and utilizing alternative networks or more efficient cognitive strategies. In human subjects, CR is commonly estimated through indicators such as educational attainment, occupational complexity, and involvement in leisure activities. Leisure activities have been identified as a significant behavioral indicator and can be classified into three main subcomponents: cognitive, physical, and social activities. This narrative review aims to summarize how leisure activities provide cognitive and/or emotional benefits and how these activities help build CR and brain resilience. Methods: Given the conceptual and methodological heterogeneity of this literature, a narrative review design was adopted for an integrative synthesis across cognitive, social, and physical domains in healthy individuals aged 18 and older. Selected studies’ primary outcomes were cognitive and/or emotional effects, with neurophysiological effects as secondary outcomes, a prerequisite for inclusion. Results: Across adulthood, participation in cognitive, social, and physical leisure activities was consistently associated with better cognitive performance and emotional well-being, with cognitive activities more closely linked to cognitive gains and social and physical activities more closely linked to combined benefits; however, evidence is observational or short-term, limiting causal inference. Conclusions: Leisure activities are consistently associated with cognitive and emotional well-being in healthy adults and may support CR development, although longitudinal and intervention research is needed to clarify causal pathways and confounders such as education and socioeconomic status.