Self-Determination for Increasing Physical Activity

描述(申请人提供)：肥胖在美国儿童和青少年中日益普遍，是对我们社会的主要健康威胁，特别是在少数族裔和低社会经济地位(SES)人群中。在青春期，体力活动(PA)减少，可能是导致儿童肥胖率这一令人震惊的趋势的重要因素。虽然已经进行了基于学校的行为干预来解决儿童和青少年的PA问题，但几乎没有证据表明这些基于课程的方法会导致总体PA的增加。本提案将评估一项以学生为中心的创新课后计划在服务不足的青少年(如少数族裔、低SES)中促进PA(7天加速度计评估)生活方式改变的效果。以学生为中心的干预与自主(动机)理论和社会认知理论是一致的，它强调提高PA的内在动机和行为技能。在以学生为中心的项目中，青少年拥有开发该项目的所有权，选择能带来乐趣和兴趣的活动，并参与制定他们自己的应对策略，以便在录制的会议期间做出有效的PA行为改变。我们的研究团队提供了初步数据，证明了以学生为中心的PA计划在南卡罗来纳州未得到充分服务的青少年中增加中等至剧烈PA(MVPA)的可行性。本申请将使用基于学校的嵌套队列设计来评估为期6个月的以学生为中心的计划与典型的课后计划在干预后和在服务不足的青少年的6个月随访中增加PA的效果。位于南卡罗来纳州的总共24所中学(每所学校有120名6年级学生；N=2,880人)将被随机分配到两个课后项目中的一个(以学生为中心的干预，典型的课后项目)。如Murray所述，我们将使用SAS/PROC混合方法使用重复测量协方差分析来分析数据。此外，中介分析将检验心理社会变量(PA自我效能感、自我概念、动机、社会支持和快乐)与MVPA之间的关系。中介将使用巴伦和肯尼概述的回归和结构方程建模技术进行测试。这项研究将解决一个重要的公共卫生问题，这一问题对减少儿童和青少年肥胖症具有重要意义。

DESCRIPTION (provided by applicant): The increasing prevalence of obesity in U.S. children and adolescents is a major health threat to our society, especially among minority and low social economic status (SES) populations. During adolescence physical activity (PA) decreases and is likely an important contributor to this alarming trend in childhood obesity rates. Although school-based behavioral interventions to address PA in children and adolescents have been conducted, little evidence suggests that these curriculum-based approaches lead to increases in overall PA. The present proposal will evaluate the efficacy of an innovative student-centered after-school program for promoting lifestyle changes in PA (7-day accelerometer assessment) among underserved adolescents (e.g., minorities, low SES). The student-centered intervention is consistent with Self-Determination (Motivation) Theory and Social Cognitive Theory in that it emphasizes increasing intrinsic motivation and behavioral skills for PA. Adolescents in the student-centered program take ownership in developing the program, select activities that generate fun and interest, and participate in generating their own coping strategies for making effective PA behavior changes during a videotaped session. Preliminary data is presented from our research team that demonstrates the feasibility of the student-centered PA program on increasing moderate-to-vigorous PA (MVPA) in underserved adolescents in South Carolina. The present application will use a school-based nested cohort design to evaluate the efficacy of a 6-month student-centered program versus a typical after school program on increasing PA at post-intervention and at 6-months follow-up in underserved adolescents. A total of 24 middle schools (120 6 th graders per school; N=2,880), located in South Carolina will be randomly assigned to one of two after-school programs (student-centered intervention, typical after-school program). We will analyze the data using a repeated measures analysis of covariance using SAS/PROC MIXED methods as outlined by Murray. In addition, mediational analyses will examine the association between psychosocial variables (PA self-efficacy, self-concept, motivation, social support, and enjoyment) and MVPA. Mediation will be tested using regression and structural equation modeling techniques as outlined by Baron and Kenny. This study will address an important public health problem that has implications for decreasing obesity in children and adolescents.