The Paradoxical Outcomes of Observing Others' Exercise Behavior on Social Network Sites: Friends' Exercise Posts, Exercise Attitudes, and Weight Concern.

This study examined the implications of observing others' exercise behavior on social network sites (SNSs). Social cognitive theory and social comparison theory were used to make predictions about the conditions under which individuals' (N = 232) exposure to exercise-related SNS posts from others in their social network were related to their weight concerns and exercise attitudes. The results revealed a paradox in which observing others' exercise posts was associated with both adaptive and maladaptive responses. The number of exercise-related SNS posts received from members of respondents' social networks was associated with greater weight concern, and this relationship was stronger among respondents who viewed exercise-related posts from network members who were similar to respondents. Yet, among respondents who had a tendency to make appearance-related upward social comparisons, the number of others' exercise-related SNS posts received was associated with pro-exercise attitudes.