Application of the Transtheoretical Model to Physical Activity and Exercise Behaviors in African-American Adolescents.

In this study, we examined the inter-relationships between Transtheoretical Model (TTM) constructs (stages of change, self-efficacy, decisional balance, processes of change) and determined the utility of TTM to predict physical activity in African-American youth. A community-based sample of 109 African-American youth (62% girls, age: 14.8 ± 0.2 years) were included in this analysis. TTM constructs were assessed using the Patient-Centered Assessment and Counseling for Exercise questionnaire. Moderate-to-vigorous physical activity (MVPA) and total physical activity (TPA) were measured objectively using accelerometry. Higher self-efficacy was observed at higher stages of change in both boys and girls (p = .02). Despite higher MVPA (p < .001) and TPA (p < .001) in boys, there were no sex differences in TTM constructs (p > .05). Stages of change predicted MVPA in girls, with those in the maintenance stage reporting significantly more MVPA compared to those in precontemplation/contemplation (p = .03) and preparation stages (p = .04). Cons predicted higher TPA in boys only (p = .02). These findings suggest specific TTM constructs relate to physical activity in African-American youth and the importance of these constructs may differ by sex.