ContextSome observational studies have found an association between television
viewing and child and adolescent adiposity.ObjectiveTo assess the effects of reducing television, videotape, and video game
use on changes in adiposity, physical activity, and dietary intake.DesignRandomized controlled school-based trial conducted from September 1996
to April 1997.SettingTwo sociodemographically and scholastically matched public elementary
schools in San Jose, Calif.ParticipantsOf 198 third- and fourth-grade students, who were given parental consent
to participate, 192 students (mean age, 8.9 years) completed the study.InterventionChildren in 1 elementary school received an 18-lesson, 6-month classroom
curriculum to reduce television, videotape, and video game use.Main Outcome MeasuresChanges in measures of height, weight, triceps skinfold thickness, waist
and hip circumferences, and cardiorespiratory fitness; self-reported media
use, physical activity, and dietary behaviors; and parental report of child
and family behaviors. The primary outcome measure was body mass index, calculated
as weight in kilograms divided by the square of height in meters.ResultsCompared with controls, children in the intervention group had statistically
significant relative decreases in body mass index (intervention vs control
change: 18.38 to 18.67 kg/m2 vs 18.10 to 18.81 kg/m2,
respectively; adjusted difference −0.45 kg/m2 [95% confidence
interval {CI}, −0.73 to −0.17]; P=.002),
triceps skinfold thickness (intervention vs control change: 14.55 to 15.47
mm vs 13.97 to 16.46 mm, respectively; adjusted difference, −1.47 mm
[95% CI, −2.41 to −0.54]; P=.002), waist
circumference (intervention vs control change: 60.48 to 63.57 cm vs 59.51
to 64.73 cm, respectively; adjusted difference, −2.30 cm [95% CI, −3.27
to −1.33]; P<.001), and waist-to-hip ratio
(intervention vs control change: 0.83 to 0.83 vs 0.82 to 0.84, respectively;
adjusted difference, −0.02 [95% CI, −0.03 to −0.01]; P<.001). Relative to controls, intervention group changes
were accompanied by statistically significant decreases in children's reported
television viewing and meals eaten in front of the television. There were
no statistically significant differences between groups for changes in high-fat
food intake, moderate-to-vigorous physical activity, and cardiorespiratory
fitness.ConclusionsReducing television, videotape, and video game use may be a promising,
population-based approach to prevent childhood obesity.

/pdf/reducing-children-s-television-viewing-to-prevent-obesity-a-4dr2e2kxkw.pdf

Reducing Children's Television Viewing to Prevent Obesity: A Randomized Controlled Trial

(2000). Assessment of Physical Activity by Self-Report: Status, Limitations, and Future Directions. Research Quarterly for Exercise and Sport: Vol. 71, No. sup2, pp. 1-14.

Assessment of physical activity by self-report: status, limitations, and future directions.

Chronic disease risk factors, including a sedentary lifestyle, may be present even in young children, suggesting that early prevention programmes may be critical to reducing the rates of chronic disease. Accurate assessment of physical activity in children is necessary to identify current levels of activity and to assess the effectiveness of intervention programmes designed to increase physical activity. This article summarises the strengths and limitations of the methods used to evaluate physical activity in children and adolescents. MEDLINE searches and journal article citations were used to locate 59 articles that validated physical activity measurement methods in children and adolescents. Only those methods that were validated against a more stringent measure were included in the review. Based on the definition of physical activity as any bodily movement resulting in energy expenditure (EE), direct observation of the individual's movement should be used as the gold standard for physical activity research. The doubly labelled water technique and indirect calorimetry can also be considered criterion measures for physical activity research, because they measure EE, a physiologic consequence closely associated with physical activity. Devices such as heart rate monitors, pedometers and accelerometers have become increasingly popular as measurement tools for physical activity. These devices reduce the subjectivity inherent in survey methods and can be used with large groups of individuals. Heart rate monitoring is sufficiently valid to use in creating broad physical activity categories (e.g. highly active, somewhat active, sedentary) but lacks the specificity needed to estimate physical activity in individuals. Laboratory and field validations of pedometers and accelerometers yield relatively high correlations using oxygen consumption (r = 0.62 to 0.93) or direct observation (r = 0.80 to 0.97) as criterion measures, although, they may not be able to capture all physical activity. Physical activity has traditionally been measured with surveys and recall instruments. These techniques must be used cautiously in a paediatric population that has difficulty recalling such information. Still, some studies have reported 73.4% to 86.3% agreement between these instruments and direct observation. Future investigations of physical activity instruments should validate the novel instrument against a higher standard. Additional studies are needed to investigate the possibility of improving the accuracy of measurement by combining 2 or more techniques. The accurate measurement of physical activity is critical for determining current levels of physical activity, monitoring compliance with physical activity guidelines, understanding the dose-response relationship between physical activity and health and determining the effectiveness of intervention programmes designed to improve physical activity.

Physical Activity Assessment in Children and Adolescents

grade intervention including school food service modifications, enhanced physical education (PE), and classroom health curricula. Twenty-eight additional schools received these components plus family education. Main Outcome Measures.\p=m-\Atthe school level, the two primary end points were changes in the fat content of food service lunch offerings and the amount of moderate-to-vigorous physical activity in the PE programs. At the level of the individual student, serum cholesterol change was the primary end point and was used for power calculations for the study. Individual level secondary end points included psychosocial factors, recall measures of eating and physical activity patterns, and other physiologic measures. Results.\p=m-\Inintervention school lunches, the percentage of energy intake from fat fell significantly more (from 38.7% to 31.9%) than in control lunches (from 38.9% to 36.2%)(P<.001 ). The intensity of physical activity in PE classes during the Child and Adolescent Trial for Cardiovascular Health (CATCH) intervention increased significantly in the intervention schools compared with the control schools (P<.02). Self-reported daily energy intake from fat among students in the intervention schools was significantly reduced (from 32.7% to 30.3%) compared with that among students in the control schools (from 32.6% to 32.2%) (P<.001). Intervention students reported significantly more daily vigorous activity than controls (58.6 minutes vs 46.5 minutes; P<.003). Blood pressure, body size, and cholesterol measures did not differ significantly between treatment groups. No evidence of deleterious effects of this intervention on growth or development was observed. Conclusion.\p=m-\TheCATCH intervention was able to modify the fat content of school lunches, increase moderate-to-vigorous physical activity in PE, and improve eating and physical activity behaviors in children during 3 school years.

Outcomes of a Field Trial to Improve Children's Dietary Patterns and Physical Activity: The Child and Adolescent Trial for Cardiovascular Health (CATCH)

Background The World Health Organization estimates that 19 million deaths worldwide are attributable to physical inactivity Chronic diseases associated with physical inactivity include cancer, diabetes and coronary heart disease Objectives The purpose of this systematic review is to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents Search strategy The search strategy included searching several databases In addition, reference lists of included articles and background papers were reviewed for potentially relevant studies, as well as references from relevant Cochrane reviews Primary authors of included studies were contacted as needed for additional information Selection criteria To be included, the intervention had to be relevant to public health practice, implemented, facilitated, or promoted by staff in local public health units, implemented in a school setting and aimed at increasing physical activity, report on outcomes for children and adolescents (aged 6 to 18 years), and use a prospective design with a control group Data collection and analysis Standardized tools were used by two independent reviewers to rate each studyﾒs methodological quality and for data extraction Where discrepancies existed discussion occurred until consensus was reached The results were summarized narratively due to wide variations in the populations, interventions evaluated and outcomes measured Main results 13,841 titles were identified and screened and 482 articles were retrieved Multiple publications on the same project were combined and counted as one project, resulting in 395 distinct project accounts (studies) Of the 395 studies 104 were deemed relevant and of those, four were assessed as having strong methodological quality, 22 were of moderate quality and 78 were considered weak In total 26 studies were included in the review There is good evidence that school-based physical activity interventions have a positive impact on four of the nine outcome measures Specifically positive effects were observed for duration of physical activity, television viewing, VO2 max, and blood cholesterol Generally school-based interventions had no effect on leisure time physical activity rates, systolic and diastolic blood pressure, body mass index, and pulse rate At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity result in positive effects Authors' conclusions Given that there are no harmful effects and that there is some evidence of positive effects on lifestyle behaviours and physical health status measures, ongoing physical activity promotion in schools is recommended at this time

/pdf/school-based-physical-activity-programs-for-promoting-gw0a82ku2q.pdf

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6-18.

The purpose of the study was to evaluate two physical activity recall instruments appropriate for use in epidemiologic studies of fifth grade children. The instruments were similar, except one (PACI) was administered in a personal interview, and the other (SAPAC) was self-completed in a group setting. Both forms required children to report the minutes during the previous day they spent in 21 common physical activities that represented a range of intensities, plus sedentary pursuits. To validate the recalls, children simultaneously wore an accelerometer (motion sensor) and a heart rate monitor for at least 8 h the day before the interview. Subjects were 55 boys and 70 girls from four regions of the United States. The Pearson correlation between the self- and interviewer-administered forms was 0.76 (P < 0.001). The interviewer-administered form correlated 0.51 (P < 0.001) with the heart rate index and 0.33 (P < 0.001) with the accelerometer score. The self-administered form correlated 0.57 (P < 0.001) with the heart rate index and 0.30 (P < 0.001) with the accelerometer score. It is concluded that both self-report forms received moderate support for their validity in all gender and ethnic subgroups. The self-administered format is more cost-effective.

Validation of interviewer- and self-administered physical activity checklists for fifth grade students.

Little is known about children's activity levels during physical education classes and how they relate to the national health objectives for the year 2000 (U.S. Public Health Service, 1991). We systematically observed students' physical activity and associated variables in 293 third-grade physical education lessons in 95 schools in 4 Child and Adolescent Trial for Cardio-vascular Health (CATCH) centers in California, Louisiana, Minnesota, and Texas. The influence of independent variables was assessed simultaneously by analysis of variance. Significant differences among study centers were evidenced for both physical activity and lesson context variables. Additionally, there were differences among variables for lesson location and teacher specialty, but not for teacher gender. Boys were more active than girls, but only during free play opportunities. The findings have widespread implications for educators responsible for developing and implementing health-related physical education programs, as wel...

Children's Activity Levels and Lesson Context During Third-Grade Physical Education

This paper presents the process evaluation model for the physical activity intervention component of the Child and Adolescent Trial for Cardiovascular Health (CATCH) and describes the major procedures used to monitor CATCH PE, the physical education intervention. The paper focuses on CATCH PE teacher training and in-service support as well as on the curriculum implementation. Monitoring training and support included assessing the in-service training workshops and the follow-up on-site assistance provided by staff. Monitoring the implementation included assessing the quantity and quality of CATCH PE instruction in terms of student physical activity engagement and lesson context, the fidelity of the curricular implementation, and the opportunities for other physical activity by children throughout the school day.

Sherry E. Woods

Papers

Validation of interviewer- and self-administered physical activity checklists for fifth grade students.

Children's Activity Levels and Lesson Context During Third-Grade Physical Education

CATCH: physical activity process evaluation in a multicenter trial.

Self-Administered Physical Activity Checklist