Table 1:

Post-Intervention Interview Topic Guide

Topic	Question	Follow Up/Probe
General Experience	Tell me what it is like to be in the study	What was it about the study was good or a bit challenging for you?
Smartwatch	Tell me about your experiences working with the smartwatch.	What did you like/dislike about the smartwatch?
Comfort level	Describe how comfortable you were operating the smartwatch in general. Describe your greatest challenge using the smartwatch.	Describe how you dealt with <difficulty mentioned>.
Self-monitoring	How did you use the smartwatch to track your step/exercise How did checking steps affect your physical activity?
Notifications/messages	Describe how the notifications and messages affected you? What was your reaction to these notifications/messages?	Describe how they affected your daily activity Describe <reaction>.
Personal activity goal	Describe your ability to reach your personal activity goals.	Describe <what was helpful>. Describe <what was challenging>.
Exercise training session	Describe how the exercise training session work for you?
Phone calls	Describe how follow-up calls from the team worked for you?	Describe <what you like> Describe <what you dislike>
Financial incentives	How did the financial incentives affect you?