Effectiveness of a computer tailored physical activity intervention in adolescents compared to a generic advice.

Objective: To investigate the differences in effects of a computer tailored physical activity advice as compared to generic information in adolescents.

Methods: Students (mean age, 14.6+/-1.2) out of 90 classes from six different Flemish schools were randomly assigned to the tailored intervention (n=563) or the generic non-tailored intervention (n=608) condition. Both interventions included information on public health recommendations and tips on becoming more active. Participants in both groups received their assessment and feedback at baseline, at 4 weeks and at 3 months during school hours. Physical activity levels were determined using an adolescent adaptation of the International Physical Activity Questionnaire (IPAQ).

Results: After 4 weeks, almost all physical activity scores increased over time in both the generic and the tailored intervention group. No differences between groups were found (all F< or =0.07). After 3 months, the generic intervention was more effective for increasing 'walking in leisure time' among students not complying with recommendations. For all other physical activity scores, no differences between groups were found (all F< or =2.3).

Conclusions: In contrast to the expectations, changes in physical activity scores did not differ between the tailored and the non-tailored intervention group. For most of the physical activity scores increases were found in both groups.