Competence inference from muscle: how and when trainers' muscle mass impacts service purchase of personal fitness training

Purpose>This study aims to examine how and when trainers' muscle mass impacts service purchase of personal fitness training, drawing upon signaling theory. Specifically, the authors investigated (1) the mediating role of perceived competence in the relationship between trainers' muscle mass (highly vs moderately muscular) and customers' service registration intention and (2) the moderating role of customer expertise in this mediating mechanism.Design/methodology/approach>The authors conceptualized trainers' muscle mass, developed its experimental stimuli and validated them through the two pretests (total n = 387). Using the validated stimuli, the authors conducted the two experiments (total n = 802). In both experiments, the authors recruited participants via MTurk using the convenience sampling method and employed a single-factor between-subject design based on random assignment.Findings>Findings supported the authors’ proporsed model. Consumers perceived highly (vs moderately) muscular trainers as more competent, which in turn engendered greater service registration intention. This effect emerged for expert consumers but not for novice consumers.Originality/value>This study is one of the first attempts to empirically test the influence of trainers' muscle mass on consumer acquisition in the context of personal fitness training. It also expands the sport marketing literature to the consumer psychology and behavior fields addressing the characteristics of sport-service providers. The findings also provide fitness organizations with managerial insights into how to effectively leverage trainers' physical appearance as a marketing tool.