Examining relationships between behaviour change technique enactment, self-determined motivation and objectively measured physical activity

Abstract

Background: Although use of Behaviour Change Techniques (BCTs) is assumed to be key to changing behavior, surprisingly few studies have assessed participants’ actual use of BCTs in and outside of interventions. Individuals can use BCTs to manage their motivation (e.g. think about benefits) and self-regulate their behaviour (e.g. self-monitoring). Furthermore, self-determined motivation and other factors potentially predicting uptake of BCTs should be identified. This study aimed to assess the associations between motivational variables from self-determination theory, enactment of motivational and self-regulatory BCTs, and objectively measured physical activity (PA). Methods: During the baseline measurements of a randomized trial (Let’s Move It), among students in vocational schools (n=442, 30% female, Md age=17), self-determined motivation and BCT use were assessed in an electronic survey. PA was measured objectively over the following 7-day period. In addition to frequentist methods, correlations and regression analyses were examined using Bayes Factors to quantify their evidential value. Results: Autonomous motivation was associated with use of both self-regulatory and motivational BCTs (CI95 for r=.40-.73, Log(BF10)=27.61-88.23). Correlations between BCT use and controlled motivation were also positive but smaller (CI95 for r=.05-.26, BF10=5.62-41.59). Motivational BCT use correlated with self-regulatory BCT use (CI95 for r=0.40-.68, Log(BF10)=27.57-116.59). BCT use predicted objectively measured PA (CI95 for r=0.17-0.76, Log(BF10)=4.28-6.58). Discussion: Our results suggest that enhancing self-determined motivation may be important in promoting BCT use. These preliminary results imply that assessing participants’ use of BCTs is feasible and may aid researchers in understanding how interventions work.