Despite evidence of the cost-effectiveness of physical activity (PA) promotion interventions in healthcare settings, translating them into practice remains challenging. This study aimed to identify implementation barriers and facilitators of a Portuguese PA consultation programme implemented in primary healthcare of the Portuguese National Health Service. Additionally, it sought to inform future implementation strategies, using a theoretically based approach.

Qualitative interview study, using both deductive and inductive approaches.

Primary healthcare units across all health administration regions of mainland Portugal.

Twenty-eight participants (six medical doctors, five exercise professionals and 17 patients) from all health regions of the country, involved in the implementation of the Portuguese PA prescription consultation.

Fifty-three categories of determinants were identified, using the Tailored Implementation for Chronic Diseases framework. Key barriers included ineffective referral processes to the consultation, challenges in integrating the intervention with existing healthcare demands and insufficient local/regional prioritisation of PA promotion. Key facilitators included high intervention acceptability, diverse community PA resources and good interpersonal skills of implementers. Drawing on the Behaviour Change Wheel, theoretically based inputs to design strategies addressing each barrier were provided.

The implementation of PA consultation was influenced by a broad range of determinants. The most frequently reported barriers are primarily structural and opportunity-related, suggesting system-level implementation strategies are most appropriate. Future strategies should consider implementing clinical standards/orientations for PA promotion, providing institutional incentives based on the attainment of PA indicators, expanding consultation coverage and diversifying referral strategies, reinforcing health system-community partnerships and strengthening training opportunities for implementers. These findings offer relevant insights for enhancing the future implementation of PA consultations, for scaling them up and, ultimately, to increase their effectiveness.