Helping individuals to behave more healthily is vital to preventing cardiovascular disease. Thanks to low costs and broad reach, digital behaviour change interventions may be a viable option for population level prevention efforts. Current digital interventions fall short of that goal however, as they do not reliably change behaviour. While there is a wealth of evidence on which behaviour change techniques (BCTs) effectively translate behavioural intentions into action, there has been surprisingly little consideration of which BCTs support the motivational processes that underlie individuals? decisions to enact behavioural changes and engage with (digital) behaviour change interventions in the first place. A Rubicon grant will allow me to fill this gap in the literature within the Department of Social Research (DSR) at the University of Helsinki. Using my expertise in literature synthesis (systematic reviewing, meta-analysis), I will first identify which BCTs are most important in supporting motivation for health behaviour change. I will then draw on the DSR?s vast knowledge of human-computer interactions, usability and computerised gaming to develop the identified BCTs into motivational components of a smartphone app, and examine how combinations of these BCTs contribute to motivation for change, sustained engagement with the app, and increases in physical activity. Keywords: behaviour change; motivation; physical activity; meta-analysis; digital interventions