Three-year maintenance of a teacher-led programme targeting motor competence in early adolescent girls.

Motor competence (MC) in youth is associated with positive health outcomes, yet few achieve their developmental capability. Although numerous MC studies address initial intervention effectiveness, fewer consider intervention sustainability. This study aimed to investigate whether teachers continued to implement an effective MC programme targeting girls (mean age 12.4 ± 0.3 years), three years post-intervention. Ongoing implementation was examined using three domains of the UK Medical Research Council's framework: (i) implementation, (ii) mechanisms of impact, and (iii) context. Teachers (n = 18) completed self-report questionnaires and participated in focus group discussions (FGs). Descriptive statistics analysed questionnaires. FGs were audio recorded, transcribed verbatim and analysed in NVivo 11 using a framework approach. All teachers had continued to implement the programme, or elements thereof, three years post-intervention. The intervention structure, in particular alignment to the physical education context and curriculum, most notably influenced ongoing programme implementation. Improvement, both teacher practice and student performance, emerged as a driver of sustained impact. The programme demand appeared to be the most important facilitator of programme sustainability. Adaptations made to enhance contextual fit of the programme, post-intervention, extended the programme reach. Framed by implementation science, these findings provide valuable insight into programme sustainability and potential scalability.