Currently, organizations that manage gyms are in constant evolution and have attained a solid position within the leisure-sports sector, although it is worth noting that they have a host of characteristics which can be analyzed but are unknown today. Therefore, the main objective of this research was to study the structural characteristics, specifically evolution, size, years operating, legal personality and number of employees. Another objective was to ascertain the effects of the economic crisis on the variables on economic evolution, including total assets and operating income, of the companies registered under the National Code of Economic Activities (CNAE) as management of gym activities in Spain, segmented by size (micro, small, medium and large) following the size criteria established by European Union directive L124\/36 (2003\/361\/EC). Generally speaking, we can conclude by stating that the organizations are small, operate with the legal personality of limited liability companies all over Spain, and that the large companies are primarily located in the Community of Madrid, Catalonia and Galicia. Furthermore, we found that their size is directly related to the economic variables studied, given that the analysis shows that the crisis has changed the positive results, given that prior to it medium-sized organizations used to have positive results whereas now small organizations do. <\/p>\n\n