Generational theory explains the changes across generations. Important historic events and social changes could affect the attitudes, behaviors, and beliefs of people of each generation. Different generations currently co-exist, among which stand out the Baby Boomers and Generations X, Y, and Z. These generations share sport spaces and sport services; yet, their behaviors could be different. This study’s aim was to analyze the differences in the relationships among perceived quality, perceived value, satisfaction, and future intentions in customers of fitness centers according to their generation. The sample was made up of 15,725 individuals (8,423 women and 7,302 men) who were customers of fitness centers in Spain. Confirmatory factor analyses (CFA) showed evidence of adequate psychometric properties of the measures and multi-group CFA indicated the factorial stability of the measurement model among different groups. Multi-group structural equation model (SEM) was performed to verify relationship congruence among the variables of different groups. The analyses revealed that there is a stronger and more significant relationship among perceived quality, satisfaction, and future intentions in Generation Z and also in the Baby Boomers. These findings indicate the presence of different behaviors according to the generational cohorts; thus, differential management is suggested for different generations of the population.