Purpose: Research has established that physical and psychological injury prevention training is effective in reducing injuries in youth team sports, but public health impact tends to be limited because such training is not widely, properly, or sustainably implemented. Insufficient involvement of end-users at the individual and organizational levels has been identified as a main barrier to implementation. Against this backdrop, the ‘Implementing injury Prevention training ROutines in TEams and Clubs in youth Team handball (I-PROTECT)’ project was initiated through dialogue between end-users and researchers with the goal of making injury prevention training an integral part of regular practice in youth handball through a series of studies. We have conducted studies within I-PROTECT and identified numerous barriers and facilitators, and address these determinants when designing the intervention.