Patient characteristics
COPD
COPD, CHRONIC OBSTRUCTIVE PULMONARY DISEASE
In total, 73 patients were randomized to either the UCG (n = 37) or IG (n = 36) after 3 months of PR, of which 65 were followed up until the end of trial (Fig. 
Flow diagram of STEP trial. Numbers refer to the total number of patients evaluated at each timepoint, independently of obtaining valid physical activity measures. PR, pulmonary rehabilitation program; COPD, Chronic Obstructive Pulmonary Disease; m, months; V, visit. Each visit (i.e. V-1, V0, V1, V2, V3) has an interval of 3 months in between
Patient characteristics at randomizationValues presented as mean ± standard deviation or as number (percentage). UCG, usual care group; IG, intervention group; BMI, n, number of patients; body mass index; kg, kilograms; m,meters; FEVCharacterization of patients at the start of PR (V-1, 3 months before randomization) is included in the Additional file 3. Overall, changes in PA in the first 3 months of PR (V-1 to V0) were modest (Δ725 ± 1822 steps/day and Δ8 ± 24 min/day MVPA). As expected, patients experienced, at the group level, prior to randomization (V-1 to V0) meaningful improvements in maximal and functional exercise tolerance and Qol (ΔWork rate (WR) = 10 ± 115 Watts, Δ6MWD = 43 ± 28 m and ΔCRDQ total = 14 ± 12 points).