Abstract Background Physical activity (PA) is a key behaviour for patients with type 2 diabetes (T2DM). However, healthcare professionals’ (HCP) recommendations (walking advice), which are short-term and individually focused, did not reduce the PA drop-out ratio in the long run. Using a socio-ecological model approach may contribute to reducing patient dropout and improving adherence to PA. The aim of this study is threefold: first, to evaluate the effectiveness of a theory-driven Nordic walking intervention using...