Self-Determination Theory and Exercise Behavior: An Examination of the Psychometric Properties of the Exercise Motivation Scale

Abstract

The purpose of these studies was to examine the psychometric properties of the Exercise Motivation Scale (EMS). One hundred forty-three undergraduates were surveyed in Study 1. Internal consistency reliability estimates ranged from .75 to .90 for the eight subscales. Discriminant validity was established via non-significant correlations with social desirability bias. The factor structure was confirmed by examining the intercorrelations of the EMS subscales which revealed a tenable simplex pattern. Differences on EMS subscales for participants at different Stages of Change supported group differentiation validity. Study 2 employed 58 undergraduates. Criterion validity was established by relationships between EMS subscales and distance walked during a self-selected intensity bout of exercise. A strong correlation between Exercise Identity Scale scores and integrated subscale scores supported the convergent validity of the integrated subscale. Overall the EMS yielded reliable scores and provided a valid means of making inferences about exercise behavior. Last, new findings about the relationship between the Self-Determination Theory and the Stages of Change Model are described which have significant applied implications.

Notes

∗, p < .05;

∗∗, p < .01