Background:Increasing caloric expenditure in physical education is considered an effective school-based approach to addressing the child obesity epidemic.This study was designed to determine synergistic influences of ...Background:Increasing caloric expenditure in physical education is considered an effective school-based approach to addressing the child obesity epidemic.This study was designed to determine synergistic influences of student characteristics and lesson factors on caloric expenditure in elementary and middle school physical education. Methods:The study used a multi-level design.Level-1 factors included personal characteristics:age,gender,and body mass index.Level-2 factors included lesson length,content,and school level.Based on the Center for Disease Control and Prevention age—gender adjusted growth chart,students in 87 classes from 14 elementary and 15 middle schools were pre-screened into "Overweight","Healthy weight",or "Thin" groups.One boy and one girl were randomly selected from each group in each class as data providers(264 elementary and 294 middle school students).Caloric expenditure was measured in 243 physical education lessons using accelerometers. Results:Analysis of variance revealed and hierarchical linear modeling confirmed separate age by body mass index,age by gender,and content by lesson—length interaction effects,suggesting that the personal and lesson factors influenced caloric expenditure independently.Older male and heavier students burned more calories in all lessons.Students burned more calories in 45—60 min sport skill or fitness lessons than in shorter (30 min) or longer(75—90 min) game or multi-activity lessons. Conclusions:The hypothesized cross-level interaction was not observed in the data.Caloric expenditure can be optimized in 45—60 min sport skill or fitness development lessons.It can be recommended that schools adopt 45—60 min lesson length and provide skill and fitness development tasks in physical education to maximize caloric expenditure.展开更多
文摘Background:Increasing caloric expenditure in physical education is considered an effective school-based approach to addressing the child obesity epidemic.This study was designed to determine synergistic influences of student characteristics and lesson factors on caloric expenditure in elementary and middle school physical education. Methods:The study used a multi-level design.Level-1 factors included personal characteristics:age,gender,and body mass index.Level-2 factors included lesson length,content,and school level.Based on the Center for Disease Control and Prevention age—gender adjusted growth chart,students in 87 classes from 14 elementary and 15 middle schools were pre-screened into "Overweight","Healthy weight",or "Thin" groups.One boy and one girl were randomly selected from each group in each class as data providers(264 elementary and 294 middle school students).Caloric expenditure was measured in 243 physical education lessons using accelerometers. Results:Analysis of variance revealed and hierarchical linear modeling confirmed separate age by body mass index,age by gender,and content by lesson—length interaction effects,suggesting that the personal and lesson factors influenced caloric expenditure independently.Older male and heavier students burned more calories in all lessons.Students burned more calories in 45—60 min sport skill or fitness lessons than in shorter (30 min) or longer(75—90 min) game or multi-activity lessons. Conclusions:The hypothesized cross-level interaction was not observed in the data.Caloric expenditure can be optimized in 45—60 min sport skill or fitness development lessons.It can be recommended that schools adopt 45—60 min lesson length and provide skill and fitness development tasks in physical education to maximize caloric expenditure.
