While previous studies have investigated online health communities and health-seeking behaviours, less attention has been directed at the growing impact of the online fitness movement. This paper draws on the concept of biopedagogies to examine the messages transmitted within fitness culture on social networking sites (SNSs), and their role as a channel for health and fitness information. To explore this, a multi-method approach was conducted. The two methods included a netnography (online ethnography) and 22 semi-structured individual interviews with female participants aged 18–24 in Australia. The study suggests that online fitness use is becoming a popular leisure activity and source of health and fitness information. It reveals how SNSs are used as a platform to gather and teach ideas of health and fitness, and the manner in which textual and photographic online communication facilitates the social construction and transmission of this knowledge. Results indicated that although fitness accounts on SNSs offer differing notions to present alternative and competing realities, users predominantly chose to follow the normalised and dominant health discourses. Noteworthy, the onus is firmly placed on the individual within these health and fitness messages to adhere to norms of correct health practices and choices. This has connotations relevant to eHealth literacy.