Treatment adherence
Based on the two-sample Figure  Percentage of Fitbit wear indicates the percentage of participants who wore the Fitbit for at least 1 day in that week. Any day during which a participant logged 500 or more steps on the Fitbit was regarded as a valid day and constituted wearing the tracker for that dayFigure  Percentage of Fitbit wear indicates the percentage of participants who wore the Fitbit all 7 days in that week. Any day during which a participant logged 500 or more steps on the Fitbit was regarded as a valid day and constituted wearing the tracker for that dayBased on the two-sample Figure Percentage of log-ins indicates the percentage of participants who logged in to the website at least 1 time in that week during the 12-week intervention