Participant characteristics and adherence
Of 280 participants randomized, 242 completed accelerometer assessments (86.4%) at 12 months, of which 236 (84.3%) provided valid accelerometer data (6 malfunctioning accelerometers); 246 (87.9%) completed valid self‐report PA questionnaires (Figure Consolidated standards of reporting trials diagram of participant flow. During months 7–12 (182 days), intervention participants tracked activity on a median (IQR) of 161 (52.5, 180.0) or 88.5% of days, which was significantly higher than self‐help participants (119.5 [11.5, 177.0], 65.7%) (