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，很可能是儿童肥胖率上升趋势的一个重要因素。几乎没有证据表明，以学校为基础的课程干预会导致总体PA的增加。因此，本提案将评估一项以学生为中心的创新课外计划在服务不足的青少年(如少数族裔、低社会保障)中促进增加PA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体育活动，并制定他们自己的应对策略，以便在录制的课程期间做出有效的PA改变。来自我们小组的初步数据表明，以学生为中心的PA计划在南卡罗来纳州缺乏服务的青少年中增加中等到剧烈的PA是可行的。拟议的项目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增加服务不足的青少年PA方面的效果。位于南卡罗来纳州的24所中学(每所学校70名6年级学生；N=1,680名)将被随机分配到两个课外项目中的一个。这项研究采用嵌套队列设计，学校而不是个人被分配到条件下，并将使用Murray概述的协方差技术的重复测量分析进行分析。我们还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)作为干预PA变化的潜在中介因素，使用Baron和Kenny概述的回归和结构方程建模技术。这项研究将解决一个重要的公共卫生问题，这将对减少服务不足的青少年中的肥胖症产生影响。

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 the increasing trend in childhood obesity rates. Little evidence suggests that school-based curriculum interventions lead to increases in overall PA. Thus, this proposal will evaluate the efficacy of an innovative student-centered after-school program for promoting increases PA 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 physical activities that generate fun and interest, and generate their own coping strategies for making effective PA changes during a videotaped session. Preliminary data from our group demonstrates the feasibility of the student-centered PA program for increasing moderate-to-vigorous PA in underserved adolescents in South Carolina. The proposed project will use a school-based nested cohort design to evaluate efficacy of a 6-month student-centered program versus typical after-school program on increasing PA in underserved adolescents. Twenty-four middle schools (70 6th graders per school; N=1,680), located in South Carolina will be randomly assigned to one of two after-school programs. The study employs a nested cohort design, with schools, rather than individuals assigned to condition and will be analyzed using repeated measures analysis of covariance techniques as outlined by Murray. We will also examine psychosocial variables (PA self-efficacy, self-concept, motivation, social support, and enjoyment) as potential mediators of the intervention on changes in PA using regression and structural equation modeling techniques as outlined by Baron and Kenny. This study will address an important public health problem that will have implications for decreasing obesity in underserved adolescents.