An intervention crossing two types of action planning with mental simulation for the promotion of physical activity among adolescents.

ABSTRACT

BACKGROUND: Four of every five adolescents do not meet the current physical activity (PA) recommendations. Therefore, there is a need for effective interventions that promote PA behavior among adolescents. OBJECTIVE: The present study aimed to evaluate the effectiveness of an integrated theory-based intervention to promote leisure-time PA (LTPA) among adolescents over a 1-month follow-up period. METHODS: Following the completion of self-reported LTPA at baseline, 316 adolescents aged 14-16 years were randomized into one of six conditions based on a 2 (outcome mental simulation present vs. absent)×3 (action planning standard vs. reasoning vs. absent) factorial design. The LTPA was measured again 1 month later. RESULTS: The intervention did not change adolescents' self-reported LTPA over a 1-month follow-up period. Participants receiving either of the intervention manipulation or combination of these intervention manipulations did not demonstrate significantly higher levels of LTPA compared with partcipants who did not receive intervention manipulations. This might be due to several reasons such as complexity of the target behavior, lack of booster sessions within the follow-up period, or seasonality issues. CONCLUSION: The results of this study suggest that such an integrated intervention may not yet be ready for implementation in promoting LTPA behavior among adolescents.