title: Within-Day Time-Varying Associations Between Behavioral Cognitions and Physical Activity in Adults.
abstract: This study used time-varying effect modeling to examine time-of-day differences in how behavioral cognitions predict subsequent physical activity (PA). Adults (N = 116) participated in three 4-day "bursts" of ecological momentary assessment (EMA). Participants were prompted with eight EMA questionnaires per day assessing behavioral cognitions (i.e., intentions, self-efficacy, outcome expectations) and wore an accelerometer during waking hours. Subsequent PA was operationalized as accelerometer-derived minutes of moderate- or vigorousintensity PA in the 2 hr following the EMA prompt. On weekdays, intentions positively predicted subsequent PA in the morning (9:25 a.m.-11:45 a.m.) and in the evening (8:15 p.m.-10:00 p.m.). Self-efficacy positively predicted subsequent PA on weekday evenings (7:35 p.m.-10:00 p.m.). Outcome expectations were unrelated to subsequent PA on weekdays. On weekend days, behavior cognitions and subsequent PA were unrelated regardless of time of day. This study identifies windows of opportunity and vulnerability for motivation-based PA interventions aiming to deliver intervention content within the context of adults' daily lives.
authors.affiliation: 1 University of Southern California.
authors.forename: Jaclyn P
authors.initials: JP
authors.lastname: Maher
authors.affiliation: 1 University of Southern California.
authors.forename: Eldin
authors.initials: E
authors.lastname: Dzubur
authors.affiliation: 1 University of Southern California.
authors.forename: Jimi
authors.initials: J
authors.lastname: Huh
authors.affiliation: 2 Northeastern University.
authors.forename: Stephen
authors.initials: S
authors.lastname: Intille
authors.affiliation: 1 University of Southern California.
authors.forename: Genevieve F
authors.initials: GF
authors.lastname: Dunton
mesh_terms: D061725:Accelerometry; D000328:Adult; D000072860:Ecological Momentary Assessment; D015444:Exercise / Q000502:physiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D020377:Self Efficacy; D013997:Time Factors
keywords: ecological momentary assessment; exercise; motivation; time-varying effect models