This dissertation explores the transformative role of social media in shaping and reshaping stable cultures within equestrian sports. Although equestrianism is Sweden’s second-largest youth sport, there is a limited body of research on the impact of social media on its practices. Social media has expanded traditional stable cultures—once confined to physical spaces—into digital environments, where riders of all ages exchange knowledge, experiences, and insights. However, this shift also raises concerns regarding the accuracy of information and the quality of online knowledge.Adopting a mixed-methods approach, this thesis aims to explore in what way equestrians shape their social media affordances and analyze how the mediatization process influences and reshapes existing stable cultures. Drawing on theories of social media affordances, self-presentation, and social interaction, the research explores how equestrians create, perceive, and navigate their media environments. The findings reveal that while sports federations acknowledge the importance of social media, they often face resource constraints that limit their ability to fully leverage these platforms. In contrast, influencers within the equestrian community have become highly mediatized, strategically adapting their content to engage followers and drive community interaction. These influencers play a pivotal role in reshaping stable cultures, blending entertainment, expertise, and personal narratives to connect with their audiences.While traditional stable cultures remain influential, new dynamics and power relations emerge within the digital media landscape. Social media influencers, seen as more authentic and relatable, enhance their credibility and impact on the equestrian community. However, these shifts also introduce risks, such as the potential for misinformation and the pressure to maintain idealized online personas, which can affect both horse welfare and the well-being of individuals in the sport.

Ultimately, this dissertation underscores the need for sport organizations to understand the evolving role of social media in shaping and re-shaping cultures and norms. For stakeholders, adapting to these digital changes is crucial to remain relevant, and foster meaningful engagement. The study concludes that mediatization is a key factor in the transformation of stable cultures, and understanding how traditional norms and digital practices intersect is vital for ensuring responsible knowledge exchange and the sustainable development of the sport.