Young people's engagement with digital health technologies is dominated by risk narratives. Yet, there are very limited understandings, from the perspectives of young people, about the health-related issues and opportunities generated by digital health technologies. This article presents new evidence on the types of health-related apps and devices young people find, select and use, and the reasons for their choices. Data were generated from a participatory mixed method design with 245 young people (age 13-18). The data were analysed using a content-led pedagogical framework. The data illustrate, vividly, young people's agency in digital health contexts and the complexity and fluidity of young people's decision-making. Schools, PE lessons and sport, as well as family members and peers, were powerful influencers on young people's digital health-related knowledge and behaviours. It is argued that better understanding young people's agency in digital health contexts offers important insights into developing effective health-related pedagogies.