Relationships Among Physical Activity, Exercise Motivation, and Basic Psychological Needs in Japanese Patients with Type 2 Diabetes: A Hypothetical Model Based on Self-Determination Theory and Structural Equation Modeling

抄録

Background and Purpose:

This study examined how basic psychological needs (BPNs)-autonomy, competence, and relatedness-relate to different types of exercise motivation and physical activity levels in adults with type 2 diabetes mellitus, using a model grounded in self-determination theory.

Methods:

An online survey was conducted of 205 Japanese adults aged 40-79 years with type 2 diabetes mellitus. Participants completed validated questionnaires on exercise motivation, physical activity, and BPNs. Structural equation modeling was used to test the proposed model and assess the relationships among the variables.

Results:

Identified regulation was the most prominent motivation type, whereas intrinsic and integrated regulation were relatively low. Autonomy and self-efficacy (used as a proxy for competence) were positively associated with autonomous motivation, and relatedness was linked to controlled motivation. A revised model that included a path from relatedness to controlled motivation demonstrated acceptable model fit, reflecting both theoretical plausibility and clinical relevance.

Conclusion:

Exercise motivation among the study participants was primarily driven by personally valued health goals rather than enjoyment. Autonomy and self-efficacy supported sustained engagement, and relationships may encourage exercise initiation through social encouragement. These findings indicate the usefulness of stage-specific, individualized support that addresses psychological needs. Although our model was developed based on a Japanese sample, it holds potential for application in context-adaptive nursing support within diabetes care and may also contribute to culturally appropriate physical activity promotion.