Electronic word of mouth on twitter about physical activity in the United States: exploratory infodemiology study.

Background: Twitter is a widely used social medium. However, its application in promoting health behaviors is understudied.

Objective: In order to provide insights into designing health marketing interventions to promote physical activity on Twitter, this exploratory infodemiology study applied both social cognitive theory and the path model of online word of mouth to examine the distribution of different electronic word of mouth (eWOM) characteristics among personal tweets about physical activity in the United States.