摘要：Objectives. We determined whether physical education (PE) taught by specialists contributed to academic development and prevention of obesity in elementary school children. Methods. Our 2-year longitudinal study involved 620 boys and girls initially in grade 3 in Australia, all receiving 150 minutes per week of PE. One group (specialist-taught PE; n = 312) included 90 minutes per week of PE from visiting specialists; the other (common-practice PE; n = 308) received all PE from generalist classroom teachers. Measurements included percentage of body fat (measured by dual-emission x-ray absorptiometry) and writing, numeracy, and reading proficiency (by government tests). Results. Compared with common-practice PE, specialist-taught PE was associated with a smaller increase in age-related percentage of body fat ( P = .02). Specialist-taught PE was also associated with greater improvements in numeracy ( P < .03) and writing ( P = .13) scores. There was no evidence of a reading effect. Conclusions. The attenuated age-related increases in percentage of body fat and enhanced numeracy development among elementary school children receiving PE from specialists provides support for the role of PE in both preventive medicine and academic development. The education and health of children are prominent considerations in the 21st century. Schools have always had a traditional focus on increasing literacy and numeracy proficiency in children, but now they are increasingly being tasked with preventing obesity as well. Regular physical activity is directly implicated in the prevention of childhood obesity; there is evidence, however, that it may also benefit cognitive development. 1 , 2 Physical education (PE) in schools is an ideal vehicle by which to promote physical activity in children because it is available to all children, and teachers have the opportunity to integrate it into the overall education process. In government elementary (primary) schools in Australia, however, PE is usually conducted by generalist classroom teachers, many of whom have little PE teacher training, thereby diminishing its potential impact. In the United States, there is evidence of a decline in the time allocated to PE, 3 – 5 which may be related to the recent introduction of national literacy and numeracy assessments. 6 Data indicating changes in the time allocated to PE in Australia over recent decades are not available; however, the Australian government has also recently introduced national assessments of literacy and numeracy. Recent publications summarizing the literature provide education authorities with little incentive to pay more attention to PE, either on academic grounds or in relation to prevention of childhood obesity. First, a comprehensive review, 7 although supportive of PE in general, could only conclude that allocating time to PE did not hinder classroom-based learning, a finding supported by a subsequent study incorporating a very large sample size. 8 Second, researchers conducting a meta-analysis found little evidence to support the claim that school-based physical activity programs were effective in combating childhood obesity. 9 We believe, however, that more positive conclusions may have emerged had all the studies involved in the review and meta-analysis met certain conditions. For example, successful PE requires trained and motivated teachers with well-designed programs, 10 a feature lacking in some studies. Moreover, cross-sectional studies were frequently employed, which are susceptible to confounding factors such as socioeconomic status. 11 On the other hand, there were 7 quasi-experimental studies considered in the review conducted by Trudeau and Shephard, 7 from which they concluded that time spent on PE did not have any negative impact on academic achievement. There might have been stronger effects on academic achievement and body composition had all of the following conditions been met within a single study: involvement of specialist PE teachers, provision of sufficient intervention time and numbers of participants, reliable and valid academic assessments, reliable assessment of body fat, and appropriate control for age-related development. Complying with these conditions, we investigated whether PE delivered by visiting specialist PE teachers in elementary schools influenced the academic performance and body composition of mid-elementary school children.
