Working (out) with fitness influencers - benefits for the fitness influencer, user health, and the endorsed brand: Key factors and the role of gender and brand familiarity.

Objective: Fitness influencers have become important digital health communicators with regard to influencing consumer health behaviours, such as physical activity. We investigate how working (out) with these new communicators can generate benefits for the fitness influencer, user health, and endorsed brands. Based on the source credibility, social identity theory, and gender congruity research, this paper aims to identify the main factors that affect users' attitudes toward the fitness influencer (influencer benefit), users' exercise intentions (user health benefit) and their purchase intentions (brand benefit), considering user and influencer gender. Methods: Two studies were conducted, both with male and female influencers and users. In study 1 (n = 496), the fitness influencer endorsed an unfamiliar brand, and in study 2 (n = 529) a familiar brand was endorsed. To test the proposed models and to estimate the path coefficients, structural equation modelling was performed. Results: Key influencing factors were identified in the two studies: For attitude toward the influencer, source credibility is the most important; for exercise intention, parasocial interaction and attitude toward the behaviour are crucial; and purchase intention is largely predicted by the brand attitude. The studies revealed gender-congruent and non-congruent tendencies for female and male respondents, and different effects of unfamiliar and familiar brands. Conclusions: Working (out) with fitness influencers can improve user attitudes toward the influencer, increase users' exercise intentions, and increase brand purchase intentions, for both unfamiliar and familiar brands. Some gender congruity and some gender incongruity effects exist. The paper discusses important implications for theory and practice.