Table 1.

Stay Strong components by trial arm.

Component	SSa Arm	SS + Coaching Arm	Intensity	Duration	Mode
Objective physical activity monitoring (Fitbit Charge 2 and data visualizations within SS)	✓	✓	Fitbit worn daily and data syncing at least once per week	1 year	Fitbit worn on wrist; Data visualizations available within the SS app
Weight self-monitoring (scale and weight data visualizations within SS)	✓	✓	Weight measured weekly with data syncing at least once per week	1 year	Data visualizations available within the SS app
Administrative message reminders (reminders for syncing, adverse event reporting, and data assessments)	✓	✓	1 message less than 230 characters	As needed over 1 year	Push notification on the smartphone
Automated personalized goal setting	—b	✓	Weekly, based on previous week’s and physical activity data	1 year	Abbreviated phone push notification plus message with image within the SS app
Automated messages: nonpersonalized	—	✓	1 message up to 225 characters, 3 per week	1 year	Abbreviated phone push notification plus a full message with visual image within the SS app
Automated messages: personalized, based on self-reported barriers	—	✓	1 message up to 225 characters, 3 per week	1 year	In-app and smartphone notification with image
Telephone-based lifestyle coaching	—	✓	Up to 30 min	3 calls in the first 9 weeks	Telephone

^aSS: Stay Strong.

^bNot applicable.