Lower price sensitivity, high rates of recommendation or customer retention are positive consequences of loyalty management. Although it is a key aspect of management, in sports services is still a subject underdeveloped. This research aims to investigate the key antecedents of loyalty by studying a public sport service (210 subjects). Using structural equation modeling and comparative qualitative analysis, allow us to study in a new way, and from the point of view symmetrical and asymmetrical, causal conditions and variables that have influence on loyalty. The results show that congruence, credibility and especially quality, constitute sufficient grounds but not necessary conditions to achieve loyalty. As recommendations to organizations, we suggest specific strategies of communication and relationship marketing in order to build a solid and reliable brand.