Effects of Personalized Messaging From a Social Media Influencer on Followers' Step Counts: A Parallel-Group...

Physical activity during adolescence is crucial for long-term health; however, many young individuals lack adequate activity levels. Social networking services (SNS) and influencers have shown promise in shaping behaviors; however, their potential to promote physical activity remains underexplored, especially when influencers are not fitness-related. This study investigated whether personalized messages from a non-fitness influencer could increase followers' physical activity.

A parallel-group randomized controlled trial was conducted for four weeks in December 2019 among followers of a non-fitness influencer of a Japanese idol group. Participants were assigned to either an individual message group (personalized messages) or an automated message group (standardized messages). Step counts were tracked via a smartphone application. Statistical analyses assessed the differences in daily steps and goal achievement (baseline average plus 1,000 steps) between the groups.

With a total of 120 participants, the mean difference in step count during Weeks 3 and 4 was significantly greater in the individual message group than in the automated message group. Goal attainment was also greater in the individual message group than in the automated message group at Weeks 2-4.

Personalized messages from non-fitness influencers effectively increased physical activity, suggesting a scalable strategy for promoting health in young populations through SNS platforms.