Abstract

This mixed-methods study aimed to develop and validate the exercise maintenance motivation (EMM) scale, designed to assess the motivation for maintaining exercise among fitness center (FC) members in Vietnam. The two-phase study was conducted to outline the development process of the EMM-FC scale, which is grounded in Self-Determination Theory (SDT). In the first qualitative phase, ten in-depth interviews and four focus groups (n = 39) were performed, identifying five components of EMM through content analysis. Following this, the scale’s content and face validity were assessed through a connecting step and pre-testing, which led to the elimination of 20 items, resulting in 40 statements. In the second phase, a cross-sectional survey (n = 280) was conducted to assess the factorial structure of the EMM-FC scale with Exploratory Factor Analysis. Findings yielded five construct dimensions with satisfactory psychometric indicators, including convergent validity, discriminant validity, and internal consistency reliability of the EMM-FC scale. The 30-item EMM-FC scale covered five SDT-driven constructs, comprising of “Exercise achievements”, “Exercise environments”, “Exercise integration with life goals”, “Exercise enjoyment”, and “Workout-aholic”, explaining 61.3% of the variance. The scores of five constructs were positively correlated with the total scores of the scale and notably distinguished between exercise maintainers and non-exercise maintainers. Further research is required to thoroughly assess the scale’s robust psychometric properties to be applied in future practical research for exercise maintenance.