Table 3.

Measures, instruments and time points

Variables	Instruments	Time point	Role
Physical activity1	Godin Leisure-Time Exercise Questionnaire41	B, A, T, M	Primary outcome
Cardiorespiratory endurance1	Submaximal Arm Ergometer Spirometry	B, A, M	Secondary outcome
Strength1	Grip strength	B, A, M	Secondary outcome
Adherence1	Tracking data	ongoing	Secondary outcome
Secondary health conditions2	National Institutes of Health Patient-Reported Outcome Measurement Information System questionnaires (pain, fatigue, sleep, quality of life)	B, A, T, M	Secondary outcome
Social cognitive theory constructs2	Exercise Self-Efficacy Scale53 Exercise Goal-setting Scale54 Multidimensional Outcomes Expectations for Exercise Scale55 Barriers in Physical Activity Questionnaire-Mobility Impairment56 Social Provisions Scale57	B, A, T, M	Mediation
Demographics2	Questionnaire	Baseline	Covariate
Health history2	Questionnaire	B, A, M	Covariate
Physical function1	Timed up and go, repeated chair stands, Timed 25-foot walk	B, A, M	Secondary outcome
Blood pressure1	Blood pressure monitor	B, A, M	Covariate
Anthropometrics1	Height, weight, BMI, waist circumference	B, A, M	Covariate
App quality and usability	eHealth Literacy Scale65 Systems Usability Scale66, Mobile Application Rating Scale67	B, M A	Covariate