| The purpose of this study was to determine the effects of an eight-week intervention program based on the Transtheoretical Model (Prochaska & DiClemente, 1983) on physical activity levels and stage of exercise behavior in high school females. A second purpose was to analyze changes in determinants, barriers, and values following the intervention program. The participants were 57 female high school students (mean age = 15). Participants were divided into control and experimental groups. All participants completed pre- and post-tests that measured physical activity, stages of exercise behavior, values, barriers, and determinants. The experimental group received an eight-week physical activity intervention program between the pre- and post-tests. The intervention included a physical activity counseling component based on the processes from the Transtheoretical Model along with workouts designed to be repeated as leisure time physical activities. The control group received no treatment between the pre- and post-tests. MANCOVA were performed on all variables. It was found that physical activity was significantly different between the experimental and control groups from the pre- to the post-test at p < .05. There was also a significant difference in the stage of exercise behavior between the control and experimental group participants at p < .05. In both instances, the differences favored the experimental group. Of the 12 values that were measured, two showed significant differences using the MANCOVA procedure. The significant values were "makes me feel good" and "improved health." Nineteen barriers of physical activity were also measured. Of these barriers, six reached levels of significance using the MANCOVA procedure favoring the experimental group. The barriers were fear of injury, lack of motivation, self-conscious about looks, time spent with family, lack of skill, and too inconvenient. Finally, nine determinants of physical activity were measured. None of the nine determinants reached significance with the MANCOVA procedure.;Overall, the intervention program was successful. Approximately 50% of the high school females (who were not in the action or maintenance stage at the pre-test) progressed at least one stage during the eight-week intervention program. The group receiving the intervention also doubled their physical activity on a two-day self-report instrument following the treatment. |
