The purpose of the Self-determination Theory is to explain motivation and behaviour based on individual differences in motivational orientations, contextual influences, and interpersonal perceptions. The theory has shown utility in explaining the antecedents and processes that underpin exercise behaviour. This review will provide an overview of the theory and its application in explaining health-related exercise motivation, behaviour, and outcomes. Recent innovative research using the theory in exercise contexts will also be reviewed in two key areas: advances in measurement and theoretical integration. Based on this evidence, recommendations for future investigations will be made advocating the development instruments to measure self-determined motivation from first principles, the adoption of experimental and intervention designs to better infer causal links between self-determined motivation and behaviour, further investigation of the role of implicit self-determined motivation in predicting behaviour, and the integration of the Self-determination Theory with other theories of motivation, e.g. the Theory of Planned Behaviour and the Achievement Goal Theory, to provide complimentary explanations of self-determined motivation in exercise contexts. Based on the evidence, the Self-determination Theory demonstrates considerable efficacy in explaining exercise motivation and behaviour. Future research should adopt these recommendations to develop the theory further with a view to informing intervention and practice.

Self-determination theory has been applied to the prediction of a number of health-related behaviors with self-determined or autonomous forms of motivation generally more effective in predicting health behavior than non-self-determined or controlled forms. Research has been confined to examining the motivational predictors in single health behaviors rather than comparing effects across multiple behaviors. The present study addressed this gap in the literature by testing the relative contribution of autonomous and controlling motivation to the prediction of a large number of health-related behaviors, and examining individual differences in self-determined motivation as a moderator of the effects of autonomous and controlling motivation on health behavior. Participants were undergraduate students (N = 140) who completed measures of autonomous and controlled motivational regulations and behavioral intention for 20 health-related behaviors at an initial occasion with follow-up behavioral measures taken four weeks later. Path analysis was used to test a process model for each behavior in which motivational regulations predicted behavior mediated by intentions. Some minor idiosyncratic findings aside, between-participants analyses revealed significant effects for autonomous motivational regulations on intentions and behavior across the 20 behaviors. Effects for controlled motivation on intentions and behavior were relatively modest by comparison. Intentions mediated the effect of autonomous motivation on behavior. Within-participants analyses were used to segregate the sample into individuals who based their intentions on autonomous motivation (autonomy-oriented) and controlled motivation (control-oriented). Replicating the between-participants path analyses for the process model in the autonomy- and control-oriented samples did not alter the relative effects of the motivational orientations on intention and behavior. Results provide evidence for consistent effects of autonomous motivation on intentions and behavior across multiple health-related behaviors with little evidence of moderation by individual differences. Findings have implications for the generalizability of proposed effects in self-determination theory and intentions as a mediator of distal motivational factors on health-related behavior.

The present study tested the cross-cultural generalizability of the measurement and structural parameters of the theory of planned behavior (TPB) among youth in a physical activity context. Pupils from five cultural groups completed measures of attitudes, subjective norms, perceived behavioral control (PBC), and intentions for physical activity. Five weeks later, participants completed self-report measures of physical activity behavior. Confirmatory factor analyses and multisample structural equation models revealed well-fitting models within each sample with minimal variations in the measurement parameters across cultures. There were a few significant cross-cultural differences in the structural relations among the TPB constructs. Attitudes predicted intentions in all samples (β range = .300 to .550), whereas the effect of the subjective norms on intention was nonsignificant in all but the Hungarian sample (β = .243). Conversely, the effect of PBC on intentions was significant (β range = .302 to .573) in all but the Hungarian sample. Findings support the generalizability of the measures and pattern of effects for the TPB among young people in a physical activity context.

We conducted a preregistered multilaboratory project ( k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result ( d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect ( d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation.