Table 3.

Optimization trial outcomes and data collection schedule.

		Week
Outcome	Measure	0	8	16
	Health history, demographics	○
Primary outcome	SST (min/day)	●	●	●
Displacement effects/ causal factors	Activity intensity	●	●	●
	Activity type (ACT24)	○	○	○
	Sleep	●	●	●
	Dietary intake (ASA24)	○		○
	Snacking, mood	●●●	●●●	●●●
Mediators	e.g., Barriers, outcome expectations, and self efficacy, see Appendix 7.	○	○	○
Clinical Measures	Weight, waist circumference	●		●
User-experience	Application usage	●●●	●●●	●●●
	User burden and compliance		○	○
	Exit interviews			○

○Survey- or interviewer-administered; ●Device-based measure; ●●●● Ecological momentary assessed; SST = Sedentary screen time. Participants are asked to wear devices for 7-days during assessment weeks and devices are mailed back and forth at each time-point. Week 0 is baseline, prior to randomization.