The purpose of this study was to examine whether variables in the Transtheoretical Model (TTM) acted more as predictors than as consequences of exercise behavior (stage of change). Students from 13 New Zealand high schools (N = 1,434) completed questionnaires corresponding to variables in the TTM (i.e., stage of exercise change, processes of change, self-efficacy, and decisional balance) at two time periods separated by 6 months. Reciprocal relationships were found between exercise behavior and the TTM variables. The TTM might be a useful framework for understanding longitudinal exercise behavior in the adolescent population.
Maddison is with the Clinical Trials Research Unit, University of Auckland, Private Bag 92019, Auckland, New Zealand; Prapavessis is at the University of Western Ontario, Canada.