Exercise-related Theory of Planned Behavior Scales

Exploring the working mechanisms of a web-based physical activity intervention, based on self-determination theory and motivational interviewing

“…Nevertheless the mechanisms underpinning the long-term effects of the interventions may be different. In this study the effects of I Move were not mediated by intrinsic motivation or identified regulation; however, as discussed above, autonomous motivation may be especially important in maintenance of changes in PA behavior, in which case intrinsic motivation and identified regulation may be more important mediators of the long-term effects of PA interventions ( Teixeira et al, 2012 , Wasserkampf et al, 2014b , Thøgersen-Ntoumani and Ntoumanis, 2006 ). Indeed, several studies found that autonomous motivation was a significant mediator of the long-term effects of SDT-based PA interventions ( Silva et al, 2011 , Van Hoecke et al, 2013 , Silva et al, 2010a , Chatzisarantis and Hagger, 2009 ).…”

“…This finding is in line with other studies ( Armitage, 2005 , Armitage and Conner, 2001 , Wasserkampf et al, 2014a ) suggesting that perceived competence (or the related concept of self-efficacy) is an important predictor of initial PA adoption. Autonomous motivation may be especially important for sustained changes in PA behavior ( Teixeira et al, 2012 , Wasserkampf et al, 2014b , Thøgersen-Ntoumani and Ntoumanis, 2006 ). Therefore, an increase in autonomous motivation three months after baseline might be associated with long-term increases in PA following both interventions.…”