From virtual trainers to companions? Examining how digital agency types, anthropomorphism, and support shape para-social relationships in online fitness

The role of virtual trainers in online fitness has increasingly captured the attention of consumers and brands as digital technology becomes more interwoven with daily life. This study extends the para‐social relationship theory by developing and testing a research model through five studies that simulate online fitness interactions. In Study 1, we examine the model and find that three characteristics (interactivity, authenticity, and companionship) positively influence consumers' social perceptions (perceived warmth and competence), para‐social relationship building, and intentions to continue using the service. Our findings also reveal that the moderating roles of coach types (human vs. avatar vs. agent) in Study 2, anthropomorphic appearance levels (high vs. low) in Study 3, and the nature of support provided (emotional vs. technical) in Study 4 significantly affect users' social perceptions and their intentions to continue using the service. Interestingly, compared to humans and avatars, using agent coaches requires greater authenticity to strengthen the para‐social relationship. When using lowanthropomorphic digital agents and avatars, building para‐social relationships more effectively promotes consumers' continued usage intentions. Additionally, the relationship between para‐social relationship building and continued usage intentions was stronger in the emotional support group than in the technical support group. In Study 5, we found that continued usage intention positively affects online fitness subscription behaviors. These findings have implications for integrating digital agencies to enhance consumer experience and engagement in health‐focused digital environments, especially for physical fitness service providers and platform course designers.