Background <p>The global population ageing presents new challenges in older adult care. To elevate the quality of life of older adults, it is essential to explore their intrinsic capacity over time. Engaging in leisure activities may exert a positive impact, which is crucial for promoting healthy ageing.</p> Method <p>This study used longitudinal data from the China Health and Retirement Longitudinal Study (CHARLS). Group-based trajectory modeling was applied to identify the trajectories of intrinsic capacity, and respondents were categorized accordingly. Leisure activities were assessed based on their intellectual and social components. The impact of social and intellectual activities on intrinsic capacity trajectories was analyzed through multinomial logistic regression, with odds ratios (OR) and 95% confidence intervals (CI) reported.</p> Results <p>Among the 1,344 respondents aged 65 and above at baseline, trajectory analysis revealed three distinct longitudinal patterns of intrinsic capacity: “persistently low trajectory” (<i>n</i> = 288, 21.43%), “persistently moderate trajectory” (<i>n</i> = 666, 49.55%), and “persistently high trajectory” (<i>n</i> = 390, 29.02%). After adjusting for sociodemographic factors, more frequent engagement in intellectual activities (OR 0.37, 95% CI 0.26–0.53) and social activities (OR 0.36, 95% CI 0.25–0.51) was associated with a reduced likelihood of being in the “persistently low trajectory” of intrinsic capacity.</p> Conclusion <p>This study indicates that increased participation in social and intellectual activities is linked to more favorable trajectories of intrinsic capacity. Therefore, older adults should be encouraged to engage more in leisure activities to promote better ageing outcomes.</p>