Physical activity during the transition from elementary school to high school

描述：体育活动为儿童和青少年提供重要的健康益处。然而，目前，随着儿童进入青春期，身体活动水平显着下降，很少有美国高中生符合当前的身体活动指南。拟议的研究（TRACK-2）将扩展现有的观察性队列研究（TRACK-1），以确定解释儿童从小学过渡到初中和高中时发生的身体活动变化的突出因素。这项研究的主要目标是为未来的身体活动干预提供信息，并扩大有关儿童和青少年时期身体活动与选定健康指标（包括身体肥胖）之间关系的知识体系。具体目标包括：（1）确定影响从小学过渡到高中的青少年与年龄有关的体育活动轨迹的个人、社会环境和物理环境因素; 2)描述青少年从小学到高中过渡期间身体活动、久坐行为和体重状况测量之间的纵向关联;以及3）描述在儿童期和青春期纵向观察的身体活动与高中生选定的健康指标之间的关系。该研究将测量大约850名9年级和11年级的学生，以及他们的父母，学校和社区，在5年级，6年级和7年级测量的所有变量，包括通过加速度计测量的身体活动。与高中生相关的其他变量也将被测量。其中三个变量--睡眠、健康和学业成绩--将在10年级的队列子样本中进行测量。这项拟议中的研究意义重大，因为它将确定导致 与年龄相关的身体活动变化，提供设计有效的公共卫生干预措施所需的知识，以增加身体活动和预防美国儿童和青少年肥胖。这项研究是创新的，因为它将是第一个跟踪一个相当大的和多样化的队列 美国青年，因为它从小学过渡到中学，进入高中，并将使用多层次的建模，以检查一个全面的和仔细测量的一套潜在的预测变化的身体活动。

DESCRIPTION: Physical activity provides important health benefits to children and adolescents. Currently, however, physical activity levels decline significantly as children progress into adolescence, and few U.S. high school students meet current physical activity guidelines. The proposed study (TRACK-2) will extend an existing observational cohort study (TRACK-1) to identify salient factors that explain the changes in physical activity that occur as children transition from elementary school through middle school and into high school. Major goals of the study are to inform future physical activity interventions and to expand the body of knowledge regarding the relationship between physical activity and selected health indicators, including body fatness, during childhood and adolescence. The specific aims include 1)To identify personal, social environmental and physical environmental factors that influence the age-related trajectory for physical activity in youth as they transition from elementary school to high school; 2) To describe the longitudinal associations among physical activity, sedentary behavior and measures of body weight status in youth as they transition from elementary school to high school; and 3) To describe the relationship between physical activity, observed longitudinally during childhood and adolescence, and selected health indicators in high school students. The study will measure in approximately 850 9th and 11th grade students, as well as their parents, schools and communities, all of the variables that were measured in the same students in 5th, 6th and 7th grades, including physical activity measured by accelerometry. Additional variables that are relevant for high school students also will be measured. Three of these variables - sleep, fitness and academic achievement - will be measured in a sub- sample of the cohort in 10th grade. The proposed research is significant because it will identify the factors that underlie age-related changes in physical activity, providing knowledge needed to design effective public health interventions to increase physical activity and prevent obesity in American children and youth. The study is innovative because it will be the first to follow a sizeable and diverse cohort of American youth as it transitions from elementary school through middle school and into high school and will use multi-level modeling to examine a comprehensive and carefully-measured set of potential predictors of change in physical activity.