1. Moving Beyond Mean Levels: Associations Between Subject-Level Variability in Psychological Determinants and Physical Activity in Older Adults.
- Author
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Maher, Jaclyn P., Labban, Jeffrey D., Hudgins, Brynn L., Hevel, Derek J., Bittel, Kelsey M., Kennedy-Malone, Laurie, and Hedeker, Donald
- Subjects
ECOLOGICAL momentary assessments (Clinical psychology) ,OLDER people ,MULTILEVEL models ,PSYCHOLOGICAL research ,MODELS & modelmaking - Abstract
Background: Research investigating the psychological determinants of physical activity (PA) tends to conceptualize determinants as stable, trait-like factors. Growing evidence suggests that people and the processes that regulate people's behavior fluctuate over short timescales (eg, hours and days). This study explores the extent to which subject-level variability (vs stability) in determinants of PA, as well as the interaction between subject-level mean and variability in those determinants, is associated with moderate- to vigorous-intensity PA (MVPA) in older adults. Methods: Older adults (N = 202) enrolled in a measurement burst design study with 3 data collection waves occurring over a 1-year period. Each data collection wave consisted of accelerometers and ecological momentary assessment to capture MVPA and psychological determinants of MVPA, respectively. Mixed-effects location scale modeling was first used to estimate subject-level means and variability in psychological determinants. These estimates were then used as predictors of daily MVPA using multilevel modeling. Results: Subject-level variability in PA intentions (β = 0.199, SE = 0.062, P =.001), self-efficacy (β = 0.133, SE = 0.064, P =.037), and planning (β = 0.154, SE = 0.062, P =.014) were positively associated with daily MVPA. Associations between subject-level variability in PA intentions and self-efficacy decreased in strength, becoming nonsignificant at higher mean levels of PA intentions (β = −0.147, SE = 0.062, P =.018) and self-efficacy (β = −0.116, SE = 0.063, P =.062). Conclusions: Greater subject-level variability in psychological determinants may be adaptive for PA engagement, especially among older adults experiencing low levels of those determinants. Moving beyond mean levels to include subject-level variability in psychological determinants of PA may help to improve our understanding of the processes that drive PA engagement. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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