Abstract
The present study investigated the stability of relationships between basic psychological needs satisfaction as well as task and barriers self-efficacy with moderate to vigorous physical activity (MVPA) in a sample of children (aged 10-14 years). Children (N = 46; 23 females) completed physical activity specific measures of basic psychological needs satisfaction and self-efficacy at baseline. One (T1) and 6 weeks (T2) later children completed a 7 day physical activity recall tapping moderate to MVPA. Task self-efficacy, autonomy and competence were significantly correlated with T1 MVPA (r's = .34, .40 & .39, p's < .05) and accounted for 22% (p < .01) of the associated variance. The relationship between T2 MVPA and competence was significant (r = .29, p = .05) and the correlation between T2 MVPA and autonomy approached significance (r = .27, p = .07) however, these variables were not predictive of T2 MVPA when analysed by hierarchical multiple regression. Evidence that in this sample of children relationships between psychological constructs and MVPA diminished when they were measured 6 weeks apart underscores the importance of assessing these variables proximally.
