Table 1.

The eight variables selected for the nomothetic model using random forest

Nature of variable	Variable	Source of data
Stress experience (emotional)	1. Midday stress	EMA on the intra-personal appraisal of stress (on a scale of 0–10) prompted on user’s smartphone in the mid-point of a 15-hour awake time window
	2. Stress two days ago	EMA on self-reported perceived stress in the end of a 15-hour awake time window
Exercise behavior (temporal feedback to stress perception)	3. Exercise yesterday	The device-recorded occurrence of cumulative high intensity physical activity, measured with at least one 30-minutes in a 24-hours period (see definition under “Physical Activity and Exercise”)
	4. Exercise two days ago
Expected exercise (self-determination)	5. Whether expected to exercise on the target day	EMA on the likelihood (on a scale of 0–10) to do at least 30 minutes of cumulative exercise that day
	6. Whether expected to exercise on the day before
Exogenous factor (environment/external)	7. Temperature range	Measured in Fahrenheit (°F)
	8. Day of a week	Cyclic weekly pattern coded as M, T, W, Th, F, Sa, Su