Post-hoc analysis
All participants were expected to be insufficiently active at inclusion, based on self-reported activity. However, both the accelerometer and IPAQ results revealed heterogeneous participant baseline activity. To take these differences into account, a post-hoc subgroup analysis was performed among “initially active” and “initially inactive” subgroups between the verbal advice group and PPIL group. “Initially inactive” participants were defined as those recording less than 5000 steps/day at baseline as measured by the accelerometer. Energy expenditure (MET-min/week), number of steps/week and time spent doing moderate intensity activity (min/week) were compared between the “initially inactive” subgroups in the PPIL and verbal advice groups and between the “initially inactive” subgroups in each group using linear mixed effect models as previously described. An increase of more than 500 steps/week will be considered as clinically significant.