How Do Social Network Sites Influence Workout Intentions: A Social Norm Approach.

People share their workout experiences on social network sites (SNSs). The present study examined how perceived exposure to these workout-related SNS posts may affect individuals' engagement in physical activities through perceived descriptive and injunctive norms of workout in their network, and how self-efficacy in workout moderated the effect of perceived descriptive norm on their workout intention, which was measured in general and specific ways. An online survey was conducted with a convenience sample of 807 responses in China. Results show that perceived descriptive norm of workout in one's network mediated the relationship between perceived exposure to workout-related SNS posts and perceived injunctive norm. In addition, self-efficacy in workout moderated the effect of perceived descriptive norm on workout intention-both general and specific-but the normative influence was stronger at a low level of self-efficacy compared to a high level. Furthermore, perceived injunctive norm only predicted the general rather than specific workout intention, suggesting that the perception of most people's approval might not be priority when people consider details about workout. These findings develop the theory of normative social behavior by illustrating the relationship between perceived descriptive and injunctive norm and shed light on the relative strength of the motivating factors of workout in different situations.