The major finding of LEAP 2 was that girls attending high schools that fully implemented a comprehensive physical activity intervention and maintained the key elements of that intervention were more physically active than girls attending other schools in the study. Girls in intervention schools were exposed to the LEAP intervention as 9th
graders, and active implementation of the intervention was terminated at the end of 9th
grade. However, personnel in the intervention schools were encouraged to implement the intervention on a permanent basis, and the follow-up assessment indicated that four of the schools that fully implemented the intervention successfully sustained the key elements three years later. The intervention had been conceptualized as an environmental intervention designed to encourage physical activity in female students. The findings of this study suggest that sustained modification of the school environment and instructional practices to encourage and support physical activity can exert a positive influence on girls’ physical activity across their entire high school careers. This sustained intervention effect would be expected to provide health benefits for girls during the critical adolescent developmental period. Further, sustained participation in higher levels of physical activity should increase the likelihood that girls will carry a physically active lifestyle into adulthood.13
LEAP 2 was unique in a number of ways. It was a large-scale study that initially involved 31 middle schools, 24 high schools, and more than 4000 adolescent girls. Approximately equal numbers of white and African American girls participated, and the participants were diverse in terms of BMI, socioeconomic status, and urban/suburban/rural location. The study used a facilitative approach and “standardized process,” rather than “standardized curriculum,”14
to implement the intervention. Teachers and school staff used a framework of “essential elements” to develop and implement an intervention that fit the environment of their school, and university-based research staff supported them with training, materials, and consultation, an approach consistent with developing school organizational capacity and enhancing sustainability of program efforts.15
The study involved post-intervention and follow-up measures, the first at the end of the intervention period (the spring of participants’ 9th
grade year) and the second three years after the active intervention had ended (the spring of the participants’ 12th
LEAP was unique in its comprehensive, systematic, and quantitative approach to measuring intervention implementation and secular trends, as well as to examining organizational change in both intervention and control schools at baseline, post-intervention, and follow-up.10
The “essential elements” of LEAP, defined prior to intervention implementation, served as the framework for the process evaluation and organizational assessments. The investigators also identified at the outset of the study activities and events that could affect implementation or outcomes of the intervention or related factors in the control schools (i.e., secular trends). These assessments allowed for identification of intervention schools that fully implemented and maintained the intervention and control schools that incorporated “LEAP-like” elements into their educational program and environment and to control for outside factors that might influence girls’ physical activity levels.
Few school-based physical activity studies have conducted follow-up assessments to examine maintenance of the intervention or intervention effects. The notable exception is CATCH, which conducted the CATCH-ON study to examine the extent of institutionalization of the CATCH program five years after the original trial ended.16
In the follow-up of CATCH-PE, students in former intervention schools had maintained the amount of PE time spent in MVPA but time spent in VPA had declined sharply, and because MVPA had increased in the former control schools there were no differences between the intervention and control schools at follow-up.17
The LEAP follow-up and CATCH-ON differed in several ways, including target group (high school vs. elementary school students), intervention focus (organizational change vs. curriculum), and follow-up measurement (individual PA and organizational measures which included a secular trend assessment vs. individual PA in PE and teacher-reported use of CATCH materials).
This study had a number of strengths and some weaknesses. Strengths included the large number of schools and participants, the nearly equal numbers of African American and white girls, the extensive process evaluation, and the long-term follow-up, which covered the period from 8th through 12th grades. Weaknesses included the use of a self-report measure of physical activity and the fact that only four of the intervention schools met the criteria for high maintainer schools. In addition, we cannot preclude that baseline characteristics of the four schools influenced their ability to implement and maintain the intervention, although our data indicate that they did not.
In conclusion, this study provides evidence that a multi-component school-based intervention that is maintained can exert a long-term, positive influence on students’ physical activity. While the present study was conducted in high schools and was targeted at girls, the core findings should apply to both boys and girls at all school levels. The findings suggest that an appropriately modified school environment can increase overall physical activity in youth.