This paper analyzes the relationship between size, age and scaling up processes in the sports third sector entities of the Valencian Region to find the patterns that lead them to grow and become social enterprises. The study is based on a field survey of 520 organizations. The results show that the majority of entities maintain simple organizational models and rudimentary financial structures that do not allow them to start growth processes, maintaining their original size. However, a smaller percentage of organizations (approximately 25%) enter in expansion processes, developing more complex financial structures, diversifying their sources of financing, generating mostof job creation in the sector and increasing their socioeconomic impact. Within these organizations, a total of three differentiated models have been found, the first arises from the alliance with public administrations, obtaining an important part of financing from the public sector and focusing its activities on offering sports services to citizens; the second is oriented to commercialize sports goods and services, obtaining a significant part of its funds from the market; thirdly, there are also organizations with a balance between their own, public and market financing, which show greater robustness by avoiding excessive dependencies on specific sources. Finally, the presence of a hybrid growth mechanism has been identified that is initially supported by public resources to boost and allow the internal development necessary to achieve the conversion of these organizations into social enterprises.