Research shows that adolescents nowadays do not exercise enough. This lack of physical activity has a great impact on their physical and mental health. Hence, the societal need is high to motivate adolescents to sport more often and adopt a healthy lifestyle. Since adolescents are excessively vulnerable for peer influence, using social media influencers might be an effective social marketing strategy to evoke behavioral change among adolescents. Earlier studies merely focused on the negative outcomes of the #fitspiration trend (fitness, sports and health info) on social media. Nevertheless, it remains unclear when and for whom a fitfluencer may function as a source of inspiration and change adolescents’ exercise behavior for the best. The current research project therefore aims to examine how fitfluencers may motivate (instead of demotivate) adolescents to sport more often and what impact this has on their mental health. In particular, the project will first examine how fitfluencers affect adolescents’ mental health and exercise behavior. Next, the project will examine how fitfluencers should frame their social media content to achieve positive health outcomes. To conclude, the project will examine how to empower followers to critically cope with fitspiration content.