Abstract: In the context of persistent population aging, non-basic public sports services, as a vital constituent of the modern public service system, have become an essential approach to enhance grassroots governance of older-adult sports and constructing a higher-quality national fitness service system. Adopting the analytical framework of “interactive relationship-collaborative model-effective governance”, the present study systematically discusses four theoretical tensions in the governance optimization process, including exercise intensity arrangement, service supply objectives, public security levels, and grassroots resource endowments, so as to construct the fundamental theoretical logic of older-adult sports grassroots governance. On this basis, the study further explores the practical logic through three typical governance cases. 1) The professional resource expansion model underpinned by interaction among government sectors. Aligned with public agenda, this model advances cross-departmental governance and engages specialized service actors. It leverages their professional strengths and coordination capacity to restructure compartmentalized grassroots professional resources sectors. 2) The professional resource expansion model underpinned by government-society interaction. By consolidating distinctive resources to engagement between social organisations and market players, alongside institutional restructuring of governmental organizational frameworks, the model streamlines the allocation of professional resources under government-society partnerships. 3) The professional resource expansion model underpinned by government-enterprise interaction. By aligning governmental demands for professional sports resources with the resource advantages of enterprises, this model helps alleviate market failure, stimulate market vitality, improve market supervision, and promote the innovative upgrading of grassroots governance paradigms. The practical logics summarized from the three cases correspond to different theoretical tensions and collaborative governance mechanisms. On this basis, anchoring the goal of empowering grassroots governance of older-adult sports through non-basic public sports services, this study finally interprets the expansion dimensions and practical implications of inclusiveness on the perspectives of inclusiveness content, responsibility allocation and value orientation, so as to better satisfy residents’ growing diverse and high-quality demands for a better life.