Contribution of timetabled physical education to total physical activity in primary school children: cross sectional study

Physical Activity at School Recess: A Key Element in Balancing Social Disparities

BACKGROUND

Since children are generally not achieving desirable levels of physical activity (PA), schools can provide an opportunity to increase their active time. This study aimed to describe individual- and social-level variables associated with PA at school recess in a culturally diverse primary school.

METHODS

This observational cross-sectional study included 131 children attending primary school. PA data were measured via accelerometry during school recess and analyzed in relation to data on sociodemographics, anthropometrics, and PA outside school. Data were analyzed using generalized linear modeling and logistic regression.

FINDINGS

Girls were more sedentary and engaged in less moderate to vigorous physical activity (MVPA) than boys (p < .001), while older girls were less active than younger girls (p < .001). Also, non-Caucasian children were less sedentary (p < .001) and engaged in more MVPA (p = .007). Belonging to ethnic minorities was also associated with lower socioeconomic status, higher body mass index, and less PA outside of school and on weekends.

CONCLUSIONS

Girls (especially older girls) and children from lower socioeconomic contexts should be prioritized when promoting PA.

IMPLICATIONS FOR SCHOOL HEALTH POLICY

School recess can be used as an effective strategy aimed at increasing PA and reducing social inequalities.

Compensation or Displacement of Physical Activity in Children and Adolescents: A Systematic Review of Empirical Studies

Regular physical activity during childhood and adolescence is associated with health benefits. Consequently, numerous health promotion programs for children and adolescents emphasize the enhancement of physical activity. However, the ActivityStat hypothesis states that increases in physical activity in one domain are compensated for by decreasing physical activity in another domain. Currently, little is known about how physical activity varies in children and adolescents within intervals of one day or multiple days. This systematic review provides an overview of studies that analyzed changes in (overall) physical activity, which were assessed with objective measurements, or compensatory mechanisms caused by increases or decreases in physical activity in a specific domain in children and adolescents. A systematic search of electronic databases (PubMed, Scopus, Web of Science, SportDiscus) was performed with a priori defined inclusion criteria. Two independent researchers screened the literature and identified and rated the methodological quality of the studies. A total of 77 peer-reviewed articles were included that analyzed changes in overall physical activity with multiple methodological approaches resulting in compensation or displacement. Of 40,829 participants, 16,265 indicated compensation associated with physical activity. Subgroup analyses separated by study design, participants, measurement instrument, physical activity context, and intervention duration also showed mixed results toward an indication of compensation. Quality assessment of the included studies revealed that they were of high quality (mean = 0.866). This review provides inconclusive results about compensation in relation to physical activity. A trend toward increased compensation in interventional studies and in interventions of longer duration have been observed.

The Contribution of Physical Education to Physical Activity Within a Comprehensive School Health Promotion Program

Purpose: Little is known about the role of physical education (PE) in a school health promotion model, particularly where wellness is placed at the forefront. The purpose of this study was to understand how PE contributes to the overall amount of moderate to vigorous physical activity (MVPA) that children receive in a school recognized for health promotion. Methods: As part of an in-depth case study, participants in grades 4-8 (N = 105) wore ActiGraph wGT3X+ accelerometers over 7 days to assess activity levels. Data were scored using ActiLife software. Using SPSS statistics software, students were grouped into low, moderate, and high activity through calculating tertile splits of average daily MVPA. Two 2 × 2 ANCOVA (sex x activity level) tests were conducted to determine the ratio of MVPA in PE to school and daily MVPA, controlling for age. Results: Participants accrued 8 min MVPA on average during PE with differences among low (6.4 ± 2.5), moderate (8.3 ± 3.7), and highly active participants (10.1 ± 4.0). ANCOVA analyses revealed non-significant interactions between sex and activity level explaining variance in contribution of PE to school MVPA (F(2, 99) = .235, p = .791, partial ŋ² = .005) and daily MVPA (F(2, 99) = .299, p = .742, partial ŋ² = .006), but significant main effects between high and low activity for daily MVPA were observed F(2, 99) = 5.118 p = .008, partial ŋ² = .094. Conclusions: PE remains a priority in supporting children's PA, particularly for those least active. Despite relatively low levels of MVPA, findings provide rationale for policy change supporting more frequent PE in schools.

Do Crowding-Out Effects Explain the Low Effect of a Health Promotion Intervention among Young People at a Vocational School?

In recent years, school-based interventions have increasingly been used as a strategy to promote good eating habits and physical activity among young people at school. However, little is known about the effect that this kind of public involvement has on the overall behavior of young people. Economists refer to the existence of a crowding-out effect when public sector engagement in influencing behavior is counteracted by behaviors at the individual level. The aim of this study was to investigate the effects of a health promotion intervention program among young people at a vocational school on the overall behavior of the students and consider whether a crowding-out effect existed when it came to health behavior. This study used data from the Gearing up the Body (GUB) intervention that was carried out at the vocational school of Uddannelsescenter Holstebro, Denmark. The study included 130 students from two vocational programs. Answers were collected from survey questions in three waves. Our results showed that intervening in the school setting had the intended impact on physical activity but an unintended impact on eating behavior. In the GUB study, we found signs of countervailing behaviors in and out of school that need to be further explored.

The Mystery of Energy Compensation

AbstractThe received wisdom on how activity affects energy expenditure is that the more activity is undertaken, the more calories will have been burned by the end of the day. Yet traditional hunter-gatherers, who lead physically hard lives, burn no more calories each day than Western populations living in labor-saving environments. Indeed, there is now a wealth of data, both for humans and other animals, demonstrating that long-term lifestyle changes involving increases in exercise or other physical activities do not result in commensurate increases in daily energy expenditure (DEE). This is because humans and other animals exhibit a degree of energy compensation at the organismal level, ameliorating some of the increases in DEE that would occur from the increased activity by decreasing the energy expended on other biological processes. And energy compensation can be sizable, reaching many hundreds of calories in humans. But the processes that are downregulated in the long-term to achieve energy compensation are far from clear, particularly in humans-we do not know how energy compensation is achieved. My review here of the literature on relevant exercise intervention studies, for both humans and other species, indicates conflict regarding the role, if any, of basal metabolic rate (BMR) or low-level activity such as fidgeting play, particularly once changes in body composition are factored out. In situations where BMR and low-level activity are not major components of energy compensation, what then drives it? I discuss how changes in mitochondrial efficiency and changes in circadian fluctuations in BMR may contribute to our understanding of energy management. Currently unexplored, these mechanisms and others may provide important insights into the mystery of how energy compensation is achieved.

Effects of a 12-week structured circuit exercise program on physical fitness levels of children with autism spectrum condition and typically developing children

PURPOSE

This study aimed to determine the effects of a circuit exercise program on the physical fitness parameters of children with atypical autism spectrum condition (ASC) and typically developing (TD) children.

METHOD

Fourteen (14) boys with atypical autism (mean age: 10.07 ± 0.25 years; weight: 24.97 ± 0.64 kg; height: 126.79 ± 1.33 cm) and 14 typically developing boys (mean age: 10.07 ± 0.30 years; weight: 26.97 ± 0.55 kg; height: 126.50 ± 0.62 cm) participated in the study. The children were divided into four groups using a random coin toss: Autism Exercise Group (AEG), Autism Control Group (ACG), Typically Developing Exercise Group (TDEG), and Typically Developing Control Group (TDCG). Testing parameters from the Bruininks-Oseretsky test of gross motor proficiency (BOT-2) included running speed and agility, balance, bilateral coordination, and the standing long jump. Handgrip strength (both sides), reaction times (visual and auditory), and flexibility tests were also performed. The exercise program consisted of three 60-minute sessions per week for 12 weeks, using the most-to-least prompting method.

FINDINGS

Significant improvements were observed for AEG in running speed and agility, balance, standing long jump, reaction times, handgrip strength, and flexibility (p < 0.05). For TDEG, only the standing long jump scores failed to significantly improve (p < .05). Comparing AEG and TDEG pre- and post-test results, the former showed 30% greater development with respect to balance, standing long jump, auditory reaction time, and handgrip strength (p < 0.05).

CONCLUSION

Based on the significant improvements in physical fitness parameters of AEG, we recommend that children with ASC start sports training immediately when diagnosed with autism and participate in structured physical activities with their peers.

A cluster randomised controlled trial of an intervention to increase the implementation of school physical activity policies and guidelines: study protocol for the physically active children in education (PACE) study

Background

In an attempt to improve children’s physical activity levels governments have introduced policies specifying the minimum time schools are to schedule physical activity each week. Despite this, the majority of schools in many jurisdictions fail to implement these policies. This study will assess the effectiveness of a multi-component implementation strategy on increasing the minutes of planned physical activity scheduled by primary school teachers each week.

Methods

A cluster randomised controlled trial will be conducted in 62 primary schools in the Hunter New England region of New South Wales, Australia. Schools will be randomly allocated to receive either a multi-component implementation strategy that includes; obtaining executive support, training in-school champions, provision of tools and resources, implementation prompts, reminders and feedback; or usual practice. The study will employ an effectiveness-implementation hybrid design, assessing both policy implementation and individual (student) behavioural outcomes. The primary trial outcome of mean minutes of physical activity scheduled by classroom teachers across the school week will be measured via teacher log-book at baseline and approximately 12 and 18 months post baseline. A nested evaluation of the impact of policy implementation on child physical activity will be undertaken of students in Grades 2 and 3. Analyses will be performed using an intention to treat framework. Linear mixed effects regression models will be used to assess intervention effects on the primary outcome at both follow-up periods.

Discussion

This study will be the one of the first well powered randomised trials internationally to examine the impact of an implementation strategy for a physical activity policy in primary schools and will address a fundamental research translation gap. Given the dearth of research, the findings will be important in informing future implementation efforts in this setting.

Trial registration

ANZCTR ACTRN12617001265369 version 1 registered 1st September 2017.

Long-term effects of the Active for Life Year 5 (AFLY5) school-based cluster-randomised controlled trial

OBJECTIVE

To investigate the long-term effectiveness of a school-based intervention to improve physical activity and diet in children.

DESIGN

Cluster-randomised controlled trial.

SETTING

60 primary schools in the southwest of England.

PARTICIPANTS

Primary school children who were aged 8-9 years at recruitment, 9-10 years during the intervention and 10-11 years at the long-term follow-up assessment.

INTERVENTION

Teacher training, provision of lesson and child-parent interactive homework plans and teaching materials.

MAIN OUTCOME MEASURES

Primary outcomes were accelerometer-assessed minutes of moderate to vigorous physical activity (MVPA) per day, accelerometer-assessed minutes of sedentary behaviour per day and reported daily consumption of servings of fruit and vegetables.

RESULTS

60 schools with 2221 eligible children were recruited. As in the previously published assessment immediately after the end of the intervention, none of the three primary outcomes differed between children in schools allocated to the intervention, compared with those in control schools at the end of the long-term follow-up (1 year after the end of the intervention). Differences in secondary outcomes were consistent with those at the immediate follow-up, with no evidence that these had diminished over time. Comparing intervention with control schools, the difference in mean child-reported screen viewing at the weekend was -16.03 min (95% CI -32.82 to 0.73), for servings of snacks per day, the difference was -0.11 (95% CI -0.39 to 0.06), in servings of high-energy drinks per day -0.20 (95% CI -0.39 to -0.01) and in servings of high-fat foods per day -0.12 (95% CI -0.39 to 0.00). None of these reached our predefined level of statistical significance, especially after accounting for multiple testing.

CONCLUSIONS

School-based curriculum interventions alone are unlikely to have a major public health impact on children's diet and physical activity.

TRIAL REGISTRATION NUMBER

ISRCTN50133740, Post-results.

Childhood obesity and the role of physical activity

Similar to adult obesity, childhood obesity has recently become a serious threat to public health. Children face the same environmental and lifestyle challenges that have made high energy dense food and drink increasingly available and opportunities for energy expenditure through transport and active play less likely. Governments are becoming concerned but research has been under funded, is relatively scarce in the UK and has provided little sound evidence on which to base interventions.

Physical activity seems to be declining and there is some evidence that time spent in sedentary pursuits such as TV watching is increasing and that this may be related to obesity. However, not all children are inactive and it may be more fruitful to independently examine different elements of activity such as play, walking and cycling as transport, organised sports, and active jobs so that children’s profiles of activity can be mapped on an individual and group level.

Recent research using accelerometry is providing insight into those elements which produce significant energy expenditure in a child’s daily routine. The school and the structure to the school day appear particularly important. It is also likely that attention will need to be paid to parenting - the anxieties that parents demonstrate when making decisions about the freedom of their child to be active. Furthermore, without neighbourhoods that are safe and attractive for activity it is unlikely that levels will be increased. For physical activity to contribute to reversing the trend in childhood obesity, a multi-factorial and multi-agency solution will be required that involves schools, the home, the neighbourhood and considered local planning and provision.

A non-equivalent group pilot trial of a school-based physical activity and fitness intervention for 10-11 year old english children: born to move

Background

PE lessons are the formal opportunity in schools for promotion of physical activity and fitness. This study aimed to evaluate the effectiveness of a pilot PE intervention on physical activity, fitness, and psychosocial outcomes.

Methods

Participants were 139 children aged 10–11 years from four schools. For six weeks children in two schools received a twice-weekly pilot ‘Born to Move’ (BTM) physical activity (PA) and fitness intervention alongside one regular PE lesson. Children in the two comparison (COM) schools received their regular twice weekly PE lessons. Outcomes were lesson time and whole-day light (LPA), moderate (MPA), vigorous (VPA), and MVPA, and sedentary time, muscular fitness, cardiorespiratory fitness (CRF), and lesson-specific perceived exertion, enjoyment, and perceived competence. Outcomes were assessed at baseline (T0), midway through the intervention (T1), and at the end (T2) using ANOVAs and ANCOVAs. Intervention fidelity was measured using child and teacher surveys at T2 and analysed using Chi-square tests.

Results

The BTM group engaged in moderate PA for significantly more lesson time (29.4 %) than the COM group (25.8 %; p = .009, d = .53). The amount of moderate-to-vigorous PA (MVPA) during the T1 BTM lesson contributed 14.0 % to total MVPA, which was significantly more than the COM group’s T1 PE lesson (11.4 %; p < .001, d = .47). The BTM group were significantly more active during the whole-day (p < .05) and the school-day (p < .01). In both groups push-up test performance increased (p < .001) and CRF test performance decreased (p < .01). Perceived exertion, enjoyment, and perceived competence increased in both groups (p < .05), but the BTM group rated their enjoyment of the T1 BTM lesson higher than the COM group rated their PE lesson (p = .02, d = .56). The children’s and teachers’ responses to the intervention indicated that the delivery aims of enjoyment, engagement, inclusivity, and challenge were satisfied.

Conclusions

The BTM pilot programme has potential to positively impact on physical activity, fitness, and psychosocial outcomes. Further, BTM was enjoyed by the children, and valued by the teachers. This study can inform the design of a modified larger-scale cluster RCT evaluation.

Correlates of sedentary behaviour in 8- to 10-year-old children at elevated risk for obesity

The purpose of this study was to describe correlates of sedentary behaviour (SED) in children at elevated risk of obesity because of parental obesity. Participants were 534 children aged 8-10 years with ≥ 1 obese parent. SED and physical activity (PA) were measured by accelerometer, screen time by self-report, and height, weight, waist circumference, and cardiovascular fitness objectively measured. Data describing the child, parents, friends, and home and neighbourhood environments were from child self-report. Higher total SED time was significantly positively associated with child's age, mother's age, Tanner stage, weight status or waist circumference, less self-reported PA, choosing screen time over PA/sport, mother saying PA/sport good for them, and fewer weekly physical education (PE) classes. Exceeding 2 h/day screen time was significantly associated with child's age, male sex, weight status or waist circumference, choosing screen time over PA/sport, and dinnertime TV viewing. Children regularly watching TV with dinner had 2.3 times greater odds (95% confidence interval (CI) 1.52, 3.58) of exceeding screen time guidelines compared with children rarely watching TV with dinner; children reporting ≤ 2 PE classes/week had 2.4 times greater odds (95% CI 1.41, 4.10) of being in the highest SED tertile compared with children reporting >2 PE classes/week. Hence, the most sedentary children are older, more biologically mature, less active, more overweight/obese, have fewer PE classes, and are more likely to choose screen time over PA and watch TV with dinner compared with less sedentary children. PE opportunities and mealtime TV viewing are potentially modifiable targets for reducing total SED and screen time in children.

Active for Life Year 5: a cluster randomised controlled trial of a primary school-based intervention to increase levels of physical activity, decrease sedentary behaviour and improve diet

Background

Previous studies of the effect of school-based interventions to improve healthy behaviours have had important limitations.

Objective

To investigate the effectiveness of a school-based intervention to increase physical activity, reduce sedentary behaviour and increase fruit and vegetable consumption.

Design

Cluster randomised controlled trial.

Setting

Sixty English primary schools.

Participants

Children in year 4 (aged 8–9 years) at recruitment, year 5 (aged 9–10 years) during the intervention and immediate follow-up and year 6 (aged 10–11 years) during 1 year of follow-up.

Intervention

Active for Life Year 5 (AFLY5) included teacher training, lesson plans, materials for 16 lessons, parent-interactive homework and written materials for school newsletters and parents.

Main outcome measures

Primary outcome measures included accelerometer-assessed levels of physical activity and sedentary behaviour, and child-reported consumption of fruit and vegetables. Secondary outcome measures included child-reported screen viewing; consumption of snacks, high-fat food and high-energy drinks; body mass index; and waist circumference.

Results

We recruited 60 schools (2221 children). At the immediate follow-up, no difference was found between children in intervention and control schools for any of the three primary outcomes. The intervention was effective on three of the nine secondary outcomes; children in intervention schools reported spending less time screen viewing at weekends [–21 minutes per day, 95% confidence interval (CI) –37 to –4 minutes per day], eating fewer servings of snacks per day (–0.22, 95% CI –0.38 to –0.05 servings of snacks per day) and drinking fewer servings of high-energy drinks per day (–0.26, 95% CI –0.43 to –0.10 servings of high-energy drinks per day) than the children in control schools. The results remained consistent 1 year later. The intervention increased children’s perception of maternal efforts to limit the time they spent screen viewing and children’s knowledge about healthy physical activity and fruit and vegetable consumption, with these two mediators explaining approximately one-quarter of the effect of the intervention on screen viewing. The intervention did not affect other mediators. The cost of implementing the intervention from a provider perspective was approximately £18 per child. Process evaluation showed that AFLY5 was implemented with a high degree of fidelity. Teachers supported the aims of AFLY5, but their views of the programme itself were mixed.

Limitations

Responses to parental questionnaires for the economic evaluation were low and we struggled to engage all teachers for the process evaluation. Although the participating schools included a range of levels of socioeconomic deprivation, class sizes and rural and urban settings, we cannot assume that results generalise to all primary schools.

Conclusions

AFLY5 is not effective at increasing levels of physical activity, reducing sedentary behaviour and increasing fruit and vegetable consumption in primary school children, but may be effective in reducing time spent screen viewing at weekends and the consumption of snacks and high-energy drinks.

Future work

Our findings suggest that school-based interventions are unlikely to have a major impact on promoting healthy levels of physical activity and healthy diets in primary school children. We would recommend trials of the effect and cost-effectiveness of more intensive family and community interventions.

Trial registration

Current Controlled Trials ISRCTN50133740.

Funding

This project was funded by the National Institute for Health Research Public Health Research programme and will be published in full inPublic Health Research; Vol. 4, No. 7. See the NIHR Journals Library website for further project information.

Do extra compulsory physical education lessons mean more physically active children--findings from the childhood health, activity, and motor performance school study Denmark (The CHAMPS-study DK)

BACKGROUND

Primarily, this study aims to examine whether children attending sports schools are more active than their counterpart attending normal schools. Secondary, the study aims to examine if physical activity (PA) levels in specific domains differ across school types. Finally, potential modifications by status of overweight/obesity and poor cardio-respiratory fitness are examined.

METHODS

Participants were from the first part of the CHAMPS-study DK, which included approximately 1200 children attending the 0th - 6th grade. At the sports schools, the mandatory physical education (PE) program was increased from 2 to 6 weekly lessons over a 3-year period. Children attending normal schools were offered the standard 2 PE lessons. PA was assessed at two different occasions with the GT3X ActiGraph accelerometer, once during winter in 2009/10 and once during summer/fall in 2010. Leisure time organized sports participation was quantified by SMS track. Based on baseline values in 2008, we generated a high-BMI and a low-cardio-respiratory fitness for age and sex group variable.

RESULTS

There were no significant differences in PA levels during total time, PE, or recess between children attending sports schools and normal schools, respectively. However, children, especially boys, attending sports schools were more active during school time than children attending normal schools (girls: β=51, p=0.065; boys: β=113, p<0.001). However, in the leisure time during weekdays children who attended sports schools were less active (girls: β=-41, p=0.004; boys: β=-72, p<0.001) and less involved in leisure time organized sports participation (girls: β=-0.4, p=0.016; boys: β=-0.2, p=0.236) than children who attended normal schools. Examination of modification by baseline status of overweight/obesity and low cardio-respiratory fitness indicated that during PE low fit girls in particular were more active at sports schools.

CONCLUSION

No differences were revealed in overall PA levels between children attending sports schools and normal schools. Sports schools children were more active than normal schools children during school time, but less active during leisure time. In girls, less organized sports participation at least partly explained the observed differences in PA levels during leisure time across school types. Baseline status of cardio-respiratory fitness modified school type differences in PA levels during PE in girls.

Pupils' and teachers' experiences of school-based physical education: a qualitative study

OBJECTIVES

To explore pupils' and teachers' experiences of physical education (PE).

STUDY DESIGN

A qualitative investigation employing semistructured interviews. Self Determination Theory was used as a guiding theory and Template Analysis was used to analyse the data.

SETTING

A secondary school in the North East of England.

PARTICIPANTS

14 pupils (aged 13 and 14, boys and girls) with a range of self-perceived competencies regarding PE and four PE teachers of the pupils (3 male, 1 female).

PRIMARY AND SECONDARY OUTCOMES

(1) Attitudes and perceptions of PE pupils regarding their experiences of compulsory school PE lessons. (2) PE teachers' experiences of teaching PE.

RESULTS

Key results from pupils and teachers suggest pupils enjoy participation in PE when they feel competent, in control and supported by others. Feeling competent depended on (1) the activity within PE and (2) the pupils perceived physical capabilities/aptitude. Feeling in control related to (1) having a choice of activities, (2) being able to set exertion levels and (3) control over clothes worn while taking part. Relationships within pupil groups and between pupils and teachers were perceived as important. Teachers could positively influence their pupils' enjoyment by understanding and supporting their personal goals, as opposed to dictating and controlling what they did and for how long, and by promoting a non-threatening atmosphere between pupils.

CONCLUSIONS

Rising obesity levels and concerns over the fitness of children and young people has returned the focus of PE to its potential as a vehicle for promoting health. This study suggests schools and PE teachers in particular can positively influence the PE experience of both boys and girls by providing more choice of activities and letting pupils make their own decisions based on their personal needs.

Effect of intervention aimed at increasing physical activity, reducing sedentary behaviour, and increasing fruit and vegetable consumption in children: active for Life Year 5 (AFLY5) school based cluster randomised controlled trial

OBJECTIVE

To investigate the effectiveness of a school based intervention to increase physical activity, reduce sedentary behaviour, and increase fruit and vegetable consumption in children.

DESIGN

Cluster randomised controlled trial.

SETTING

60 primary schools in the south west of England.

PARTICIPANTS

Primary school children who were in school year 4 (age 8-9 years) at recruitment and baseline assessment, in year 5 during the intervention, and at the end of year 5 (age 9-10) at follow-up assessment.

INTERVENTION

The Active for Life Year 5 (AFLY5) intervention consisted of teacher training, provision of lesson and child-parent interactive homework plans, all materials required for lessons and homework, and written materials for school newsletters and parents. The intervention was delivered when children were in school year 5 (age 9-10 years). Schools allocated to control received standard teaching.

MAIN OUTCOME MEASURES

The pre-specified primary outcomes were accelerometer assessed minutes of moderate to vigorous physical activity per day, accelerometer assessed minutes of sedentary behaviour per day, and reported daily consumption of servings of fruit and vegetables.

RESULTS

60 schools with more than 2221 children were recruited; valid data were available for fruit and vegetable consumption for 2121 children, for accelerometer assessed physical activity and sedentary behaviour for 1252 children, and for secondary outcomes for between 1825 and 2212 children for the main analyses. None of the three primary outcomes differed between children in schools allocated to the AFLY5 intervention and those allocated to the control group. The difference in means comparing the intervention group with the control group was -1.35 (95% confidence interval -5.29 to 2.59) minutes per day for moderate to vigorous physical activity, -0.11 (-9.71 to 9.49) minutes per day for sedentary behaviour, and 0.08 (-0.12 to 0.28) servings per day for fruit and vegetable consumption. The intervention was effective for three out of nine of the secondary outcomes after multiple testing was taken into account: self reported time spent in screen viewing at the weekend (-21 (-37 to -4) minutes per day), self reported servings of snacks per day (-0.22 (-0.38 to -0.05)), and servings of high energy drinks per day (-0.26 (-0.43 to -0.10)) were all reduced. Results from a series of sensitivity analyses testing different assumptions about missing data and from per protocol analyses produced similar results.

CONCLUSION

The findings suggest that the AFLY5 school based intervention is not effective at increasing levels of physical activity, decreasing sedentary behaviour, and increasing fruit and vegetable consumption in primary school children. Change in these activities may require more intensive behavioural interventions with children or upstream interventions at the family and societal level, as well as at the school environment level. These findings have relevance for researchers, policy makers, public health practitioners, and doctors who are involved in health promotion, policy making, and commissioning services. Trial registration Current Controlled Trials ISRCTN50133740.

Physical education can improve insulin resistance: the LOOK randomized cluster trial

PURPOSE

As impaired glucose metabolism may arise progressively during childhood, we sought to determine whether the introduction of specialist-taught school physical education (PE) based on sound educational principles could improve insulin resistance (IR) in elementary school children.

METHODS

In this 4-yr cluster-randomized intervention study, participants were 367 boys and 341 girls (mean age = 8.1 yr, SD = 0.35) initially in grade 2 in 29 elementary schools situated in suburbs of similar socioeconomic status. In 13 schools, 100 min·wk-1 of PE, usually conducted by general classroom teachers, was replaced with two classes per week taught by visiting specialist PE teachers; the remaining schools formed the control group. Teacher and pupil behavior were recorded, and measurements in grades 2, 4, and 6 included fasting blood glucose and insulin to calculate the homeostatic model of IR, percent body fat, physical activity, fitness, and pubertal development.

RESULTS

On average, the intervention PE classes included more fitness work than the control PE classes (7 vs 1 min, P < 0.001) and more moderate physical activity (17 vs 10 min, P < 0.001). With no differences at baseline, by grade 6, the intervention had lowered IR by 14% (95% confidence interval = 1%-31%) in the boys and by 9% (95% confidence interval = 5%-26%) in the girls, and the percentage of children with IR greater than 3, a cutoff point for metabolic risk, was lower in the intervention than the control group (combined, 22% vs 31%, P = 0.03; boys, 12% vs 21%, P = 0.06; girls, 32% vs 40%, P = 0.05).

CONCLUSIONS

Specialist-taught primary school PE improved IR in community-based children, thereby offering a primordial preventative strategy that could be coordinated widely although a school-based approach.

ActiTrainer-determined segmented moderate-to-vigorous physical activity patterns among normal-weight and overweight-to-obese Czech schoolchildren

This study uncovered the patterns of moderate-to-vigorous physical activity (MVPA) in normal-weight and overweight/obese children before, during, and after school lessons. ActiTrainer-based MVPA was assessed over 2 school days (with and without a physical education lesson [PEL] in a sample of three hundred thirty-eight 9- to 11-year-old children (50.3 % female; 29.6 % overweight/obese), in the Czech Republic, during spring 2012. MVPA was quantified based on the step count (number), MVPA duration, and MVPA heart-rate response (minutes). No differences in the MVPA based on the time during the school day were confirmed in normal-weight versus overweight/obese girls, whereas normal-weight boys significantly exceed their overweight/obese peers in step count and after-school and daylong MVPA. Active participation in PEL contributes to a significantly higher step count, exercise duration, and MVPA heart-rate response in normal-weight and overweight/obese boys (p < 0.001) and normal-weight (p < 0.001) and overweight/obese (p < 0.04) girls during school time. Moreover, active participation in PEL significantly (p < 0.04) increases the overall daily step count, duration, and MVPA heart-rate response in normal-weight boys and overweight/obese girls. Active exercise during PEL accounted for 16.7 % of the total number of steps, 25.1 % of overall MVPA duration, and 24.1 % of the MVPA heart-rate response in 9- to 11-year-old children. During days with a PEL, a significantly (p < 0.02) higher number of overweight/obese girls and a higher number of normal-weight boys achieved the duration of 60 min/day of MVPA compared with days without a PEL.

CONCLUSION

Adding one PEL or an equivalent amount of MVPA to the daily school routine appears to be a promising strategy to effectively increase daily MVPA, particularly among overweight/obese girls.

Effects of a novel school-based cross-curricular physical activity intervention on cardiovascular disease risk factors in 11- to 14-year-olds: the activity knowledge circuit

PURPOSE

This study investigates cardiovascular disease risk factor response in adolescents following introduction of brisk walking into curriculum lessons.

DESIGN

Quasi-experimental.

SETTING

School-based.

SUBJECTS

An intervention group consisted of 115 (aged 12.4 ± 0.5 y) year eight participants, and 77 (aged 12.1 ± 1.1 y) year seven and year nine participants formed a control.

INTERVENTION

An 18-week cross-curricular physical activity intervention was implemented in one secondary school.

MEASURES

Adiposity variables, blood pressure, lipids, lipoproteins, glucose, insulin, high-sensitivity C-reactive protein, high-molecular-weight adiponectin, aerobic fitness, physical activity behavior, and diet were assessed preintervention and postintervention.

ANALYSIS

Dependent and independent t-tests.

RESULTS

Prevalence of elevated waist circumference (9.8% vs. 6.9%), systolic blood pressure (3.3% vs. 0%), triglycerides (2.5% vs. 1.2%), and reduced high density lipoprotein cholesterol (3.7% vs. 2.7%) decreased in the intervention group. Significant improvements in high density lipoprotein cholesterol to total cholesterol ratio (mean ± SD: 2% ± 4% [confidence interval (CI)(0.05)  =  1% to 2%], t(80)  =  -3.5, p  =  .001) and glucose (-.1 ± .4 mmol/L [CI(0.05)  =  -.2% to 0%], t(79)  =  3.2, p  =  .002) were evident for the intervention group.

CONCLUSION

The Activity Knowledge Circuit may prove to be a sustainable, effective, and cost-effective strategy to engage schoolchildren in physical activity on a daily basis. A longer-duration intervention is required to fully understand risk factor response in adolescents.

Using stand/sit workstations in classrooms: lessons learned from a pilot study in Texas

Childhood obesity has grown into a national epidemic since the 1980s. Many school-based intervention efforts that target childhood obesity involve curriculum and programming that demands instructional time, which disincentivizes school participation. Stand-biased classrooms are an environmental intervention that promotes standing rather than sitting by utilizing standing height desks that allow students to stand during normal classroom activities. The quasi-experimental pilot study was conducted in 5 first-grade classrooms in a Texas elementary school, with 2 control classrooms, 2 treatment classrooms, and 1 classroom that was a control in the fall and treatment in the spring (to allow for within-group comparisons). This intervention has been shown effective in significantly increasing caloric expenditure. In addition, the present study reveals potential behavioral effects from standing. This article presents lessons learned from the pilot study that may prove useful for others implementing similar interventions and calls for additional research on the academic benefits of standing for students.

Effect of an after-school intervention on increases in children's physical activity

PURPOSE

Evaluate the effect of an after-school intervention on physical activity program changes and individual behaviors among children.

METHODS

A quasi-experimental evaluation of a YMCA-driven environmental change intervention with 16 intervention and 16 control sites in four metropolitan areas in the United States. Intervention sites participated in learning collaboratives designed to promote physical activity and nutrition through environmental change, educational activities, and parent engagement. Behavioral foci included increasing overall physical activity levels as well as combined moderate and vigorous physical activity and vigorous physical activity. Outcomes were assessed longitudinally using preintervention and follow-up surveys of program implementation and accelerometer measures of physical activity. ActiGraph accelerometer data were collected from a sample of 212 children, ages 5-11 yr, attending the programs. On average, 3 d of data were gathered per child. Reliability of the accelerometer counts averaged 0.78. Multivariate regression models were used to control for potential confounding variables and to account for clustering of observations.

RESULTS

Data indicate greater physical activity increases in children in intervention versus control sites after modest intervention implementation. Controlling for baseline covariates, children in intervention sites showed greater increases in average physical activity level than in control sites (76 counts per minute, P = 0.037, 95% confidence interval (CI) = 8.1-144) and more minutes of moderate and vigorous physical activity (10.5 min·d(-1), P = 0.017, 95% CI = 1.5-18.6), minutes of moderate physical activity (5.6 min·d(-1), P = 0.020, 95% CI = 0.99-10.2), and minutes of vigorous physical activity (5.1 min·d(-1), P = 0.051, 95% CI = 0.21-9.93).

CONCLUSIONS

Results indicate significant increases in daily physical activity among children in intervention versus control sites. This study documents the effectiveness of an environmental change approach in an applied setting.

Contribution of physical education to overall physical activity

For many children, physical activity (PA) during physical education (PE) lessons provides an important opportunity for being physically active. Although PA during PE has been shown to be low, little is known about the contribution of PA during PE to overall PA. The aim was therefore to assess children's PA during PE and to determine the contribution of PE to overall PA with special focus on overweight children. Accelerometer measurements were done in 676 children (9.3 ± 2.1 years) over 4-7 days in 59 randomly selected classes. Moderate-and-vigorous PA (MVPA; ≥ 2000 counts/min) during PE (MVPAPE), overall MVPA per day (MVPADAY), and a comparison of days with and without PE were calculated by a regression model with gender, grade, and weight status (normal vs overweight) as fixed factors and class as a random factor. Children spent 32.8 ± 15.1% of PE time in MVPA. Weight status was not associated to MVPAPE . MVPAPE accounted for 16.8 ± 8.5% of MVPADAY, and 17.5 ± 8.2% in overweight children. All children were more active on days with PE than on days without PE (differences: 16.1 ± 29.0 min of MVPADAY; P ≤ 0.001; 13.7 ± 28.0 min for overweight children). Although MVPAPE was low, PE played a considerable role in providing PA and was not compensated by reducing extracurricular MVPA.

Effects of a physical education intervention on cognitive function in young children: randomized controlled pilot study

Background

Randomized controlled trials (RCT) are required to test relationships between physical activity and cognition in children, but these must be informed by exploratory studies. This study aimed to inform future RCT by: conducting practical utility and reliability studies to identify appropriate cognitive outcome measures; piloting an RCT of a 10 week physical education (PE) intervention which involved 2 hours per week of aerobically intense PE compared to 2 hours of standard PE (control).

Methods

64 healthy children (mean age 6.2 yrs SD 0.3; 33 boys) recruited from 6 primary schools. Outcome measures were the Cambridge Neuropsychological Test Battery (CANTAB), the Attention Network Test (ANT), the Cognitive Assessment System (CAS) and the short form of the Connor's Parent Rating Scale (CPRS:S). Physical activity was measured habitually and during PE sessions using the Actigraph accelerometer.

Results

Test- retest intraclass correlations from CANTAB Spatial Span (r 0.51) and Spatial Working Memory Errors (0.59) and ANT Reaction Time (0.37) and ANT Accuracy (0.60) were significant, but low. Physical activity was significantly higher during intervention vs. control PE sessions (p < 0.0001). There were no significant differences between intervention and control group changes in CAS scores. Differences between intervention and control groups favoring the intervention were observed for CANTAB Spatial Span, CANTAB Spatial Working Memory Errors, and ANT Accuracy.

Conclusions

The present study has identified practical and age-appropriate cognitive and behavioral outcome measures for future RCT, and identified that schools are willing to increase PE time.

Trial registration number

ISRCTN70853932 (http://www.controlled-trials.com)

An initial evaluation of a long-term, sustainable, integrated community-based physical activity program for adults with intellectual disability

BACKGROUND

Physical activity (PA) programs for adults with intellectual disability (ID) have positive impacts, at least in the short term. No research has been reported on the effect of long-term engagement in PA programs for adults with ID. This paper explores the physical and psychosocial benefits gained by two individuals with mild ID who participated in a long-term PA program.

METHOD

Accelerometery was used to collect PA data during the program and for 7-day periods outside of the program. To explore the psychosocial outcomes gained from participating in the program, participants and their caregivers were interviewed about their participation experiences.

RESULTS

Across time, a decrease in the amount of light activity engaged in during sessions was found, with participants gradually increasing their moderate to vigorous activity. Psychosocial benefits, including meeting new people and gaining social acknowledgement were reported by participants and caregivers.

CONCLUSIONS

Long-term, sustainable, low cost PA programs (such as the one under investigation) can minimise barriers to physical activity for people with ID.

Effect of school-based interventions on physical activity and fitness in children and adolescents: a review of reviews and systematic update

BACKGROUND

School-based interventions are thought to be the most universally applicable and effective way to counteract low physical activity (PA) and fitness although there is controversy about the optimal strategy to intervene.

OBJECTIVES

The objective of this review was to summarise recent reviews that aimed to increase PA or fitness in youth and carry out a systematic review of new intervention studies.

METHODS

Relevant systematic reviews and original controlled and randomised controlled school-based trials with a PA or fitness outcome measure, a duration of ≥12 weeks, a sufficient quality and involvement of a healthy population aged 6-18 years that were published from 2007 to 2010 were included. Results In these reviews, 47-65% of trials were found to be effective. The effect was mostly seen in school-related PA while effects outside school were often not observed or assessed.

CONCLUSIONS

The school-based application of multicomponent intervention strategies was the most consistent, promising strategy, while controversy existed regarding the effectiveness of family involvement, focus on healthy populations at increased risk or duration and intensity of the intervention. All 20 trials in the review update showed a positive effect on in-school, out-of-school or overall PA, and 6 of 11 studies showed an increase in fitness. Taking into consideration both assessment quality and public health relevance, multicomponent approaches in children including family components showed the highest level of evidence for increasing overall PA. This review confirms the public health potential of high quality, school-based PA interventions for increasing PA and possibly fitness in healthy youth.

Can we modulate physical activity in children? No

Intuition tells us that physical activity is central to weight reduction in obese children. Evidence, on the other hand, suggests that increases in physical activity are difficult to achieve in the short term, and may not be possible in the long term. One explanation could be an 'activitystat', a feedback loop in the child's brain that controls physical activity according to a set point. This brief article, which argues that it may not be possible to modulate the activity of children, reviews the principles of feedback control as they apply to physical activity, discusses evidence for its central control, and demonstrates how a physical activity control loop might operate to defend the set point. Studies restricted to objective measurement suggest that the physical activity of children varies in a systematic, rather than random manner. It varies little from environment to environment, from year to year or from place to place. Where children undertake more activity at one time of day, they appear to compensate at another. Systematic variation of this kind implies control, and the control of physical activity appears to lie with the child, not with his environment. Perturbation (temporary change in response to disturbance) during short-term physical activity interventions may be mistaken for modulation (permanent change in set point), a fundamentally different response. Perturbation lasts no longer than the disturbance that causes it, and there is little evidence that interventions raise activity long term, if at all.

Evidence, theory and context--using intervention mapping to develop a school-based intervention to prevent obesity in children

Background

Only limited data are available on the development and feasibility piloting of school-based interventions to prevent and reduce obesity in children. Clear documentation of the rationale, process of development and content of such interventions is essential to enable other researchers to understand why interventions succeed or fail.

Methods

This paper describes the development of the Healthy Lifestyles Programme (HeLP), a school-based intervention to prevent obesity in children, through the first 4 steps of the Intervention Mapping protocol (IM). The intervention focuses on the following health behaviours, i) reduction of the consumption of sweetened fizzy drinks, ii) increase in the proportion of healthy snacks consumed and iii) reduction of TV viewing and other screen-based activities, within the context of a wider attempt to improve diet and increase physical activity.

Results

Two phases of pilot work demonstrated that the intervention was acceptable and feasible for schools, children and their families and suggested areas for further refinement. Feedback from the first pilot phase suggested that the 9-10 year olds were both receptive to the messages and more able and willing to translate them into possible behaviour changes than older or younger children and engaged their families to the greatest extent. Performance objectives were mapped onto 3 three broad domains of behaviour change objectives - establish motivation, take action and stay motivated - in order to create an intervention that supports and enables behaviour change. Activities include whole school assemblies, parents evenings, sport/dance workshops, classroom based education lessons, interactive drama workshops and goal setting and runs over three school terms.

Conclusion

The Intervention Mapping protocol was a useful tool in developing a feasible, theory based intervention aimed at motivating children and their families to make small sustainable changes to their eating and activity behaviours. Although the process was time consuming, this systematic approach ensures that the behaviour change techniques and delivery methods link directly to the Programme's performance objectives and their associated determinants. This in turn provides a clear framework for process analysis and increases the potential of the intervention to realise the desired outcome of preventing and reducing obesity in children.

Perception of competence in middle school physical education: instrument development and validation

Perception of Competence (POC) has been studied extensively in physical activity (PA) research with similar instruments adapted for physical education (PE) research. Such instruments do not account for the unique PE learning environment. Therefore, an instrument was developed and the scores validated to measure POC in middle school PE. A multiphase design was used consisting of an intensive theoretical review, elicitation study, prepilot study, pilot study, content validation study, and final validation study (N=1281). Data analysis included a multistep iterative process to identify the best model fit. A three-factor model for POC was tested and resulted in root mean square error of approximation = .09, root mean square residual = .07, goodness offit index = .90, and adjusted goodness offit index = .86 values in the acceptable range (Hu & Bentler, 1999). A two-factor model was also tested and resulted in a good fit (two-factor fit indexes values = .05, .03, .98, .97, respectively). The results of this study suggest that an instrument using a three- or two-factor model provides reliable and valid scores ofPOC measurement in middle school PE.

Body fatness and physical activity levels of young children

BACKGROUND

The decline in physical activity levels of young children seems to be combined with a high prevalence of obesity and overweight and a reduction in the participation in organized sport. With the ever-increasing interest in exploring the relationship between physical activity and obesity amongst children, it is important to provide a more precise estimate of both physical activity and body fatness. A significant proportion of previous research on this topic has relied on self-report methods to assess physical activity and body mass index as a proxy for actual body fatness. There is a need to investigate the relationships between physical activity and fatness in children using objective methods.

AIM

This study was conducted in order to explore the relationship between physical activity patterns and percentage body fat amongst a group of primary school children.

SUBJECTS AND METHODS

Forty-seven primary school children (boys, n = 23; girls, n = 24) participated in this study. They were randomly selected from children in years 5 and 6 (9-11 year olds) of four schools drawn from the same catchment area in the city of Birmingham, UK. The frequency, intensity and duration of physical activity were determined using continuous heart rate monitoring from 8:30 am to 8:30pm over three separate days (two weekdays and one weekend day). Percentage body fat was assessed using air displacement plethysmography.

RESULTS

Results indicated that 52% of children did not achieve a single 15-min bout of sustained moderate physical activity over the three days of monitoring. Independent t-tests revealed that girls were significantly fatter (t44 = -3.126, p=0.003) than boys. There was no significant difference (t45 = 0.225, p > 0.05) between boys and girls in accumulated time spent with heart rates above the moderate physical activity threshold. Pearson's product moment correlation coefficients revealed no significant (r= -0.017, p> 0.05) relationship between per cent body fat and average daily time spent in moderate and vigorous activity.

CONCLUSION

Despite the prediction to the contrary, there was no evidence of a significant relationship between percentage body fat of children and time spent in moderate and vigorous activity. Additionally, while there were no significant gender differences in physical activity patterns, children were more physically active during weekdays than weekends.

In-school and out-of-school physical activity in primary and secondary school children

The aim of this study was to compare in-school and out-of-school physical activity within a representative sample. Socio-demographic, physical activity, and anthropometric data were collected from a random sample of children (250 boys, 253 girls) aged 3-16 years attending nine primary and two secondary schools. Actigraph GT1M accelerometers, worn for seven days, were used to estimate physical activity levels for in-school (typically 09.00-15.00 h), out-of-school (weekday), and weekend periods. Physical activity as accelerometer counts per minute were lower in school versus out of school overall (in school: 437.2 +/- 172.9; out of school: 575.5 +/- 202.8; P < 0.001), especially in secondary school pupils (secondary: 321.6 +/- 127.5; primary: 579.2 +/- 216.3; P < 0.001). Minutes of moderate-to-vigorous physical activity accumulated in school accounted for 29.4 +/- 9.8% of total weekly moderate-to-vigorous physical activity overall but varied by sector (preschool: 37.4 +/- 6.2%; primary: 33.6 +/- 8.1%; secondary: 23.0 +/- 9.3%; F = 114.3, P < 0.001). Approximately half of the children with the lowest in-school activity compensated out of school during the week (47.4%) and about one-third at the weekend (30.0%). Overall, physical activity during the school day appears to be lower than that out of school, especially in secondary school children, who accumulate a lower proportion of their total weekly moderate-to-vigorous physical activity at school than younger children. As low in-school activity was compensated for beyond the school setting by less than half of children, promoting physical activity within the school day is important, especially in secondary schools.

Participation in organized weekly physical exercise in obese adolescents reduced daily physical activity

AIM

The aim of this study was to describe the impact of organized weekly exercise for 13 weeks on aerobic fitness, objectively assessed habitual physical activity and body weight in obese adolescents.

METHODS

After inclusion and diagnostic evaluation, the adolescents were randomized to either an exercise group or to a control group which lasted for 13 weeks and consisted of a variety of group exercise activities. Out of 47 adolescents 31 (66%) could be evaluated, 16 in the exercise group and 15 in the control group.

RESULTS

After the intervention, the exercise group had decreased the daily time spent in moderate activity by 17 (32) min/day (p < 0.05), and the average intensity by 60 (96) counts/min (p < 0.05). A tendency for increased time spent in inactivity was found (37 min/day). No differences were seen in the control group for any of the variables measured.

CONCLUSION

The exercise group showed, in contrast to expectations, a reduction in total daily physical activity with organized physical exercise compared to the control group. This may partly explain the failure of many intervention trials.

Children from low-income families have less access to sports facilities, but are no less physically active: cross-sectional study (EarlyBird 35)

BACKGROUND

Rising levels of childhood obesity have led to an increasing number of Government sponsored initiatives attempting to stem the problem. Much of the focus to date has been on physical activity and out-of-school activity in particular. There is an assumption that children from low-income families suffer most where there is a lack of structured physical education in school. Accordingly, provision of additional facilities for sport and other forms of active recreation tend to target areas of socio-economic deprivation.

AIM

We have assessed the relationship between parental income, the use of out-of-school sports facilities and the overall physical activity of young children across a wide socio-economic range.

METHODS

Total weekly physical activity was measured, objectively, over 7 days both at 7 years and 8 years in a healthy cohort of 121 boys and 93 girls using actigraph accelerometers. Questionnaires were used to establish parental income and parents reported the child's weekly use of out-of-school facilities for structured physical activity.

RESULTS

Children from low-income families attended significantly fewer sessions of structured out-of-school activities than those from wealthier families (r = 0.39), with a clear dose-response relationship across income groups. Nevertheless, total physical activity, measured objectively over seven continuous days, showed no relationship between parental income and the mean activity level of the children (r = -0.08). Nor did we find a relationship between parental income and time spent in higher intensity activity (r = -0.04).

CONCLUSION

Social inequality appears to have little impact on physical activity in young children. Those from poorer families make less use of facilities for structured activity out-of-school but they nevertheless record the same overall level of activity as others. What they lack in opportunity they appear to make up in the form of unstructured exercise. Improving provision for sport may not lead to the expected rise in activity levels in young children.

The provision of compulsory school physical activity: associations with physical activity, fitness and overweight in childhood and twenty years later

Background

To determine whether the provision of higher levels of compulsory school physical activity is associated with higher physical activity and fitness levels and less overweight in childhood and 20 years later.

Methods

As part of the 1985 Australian Schools Health and Fitness Survey, 109 schools reported how much compulsory physical education (PE) and school sport they provided and were classified as low (<110 and <150 minutes/week for primary and secondary schools, respectively), medium (110–149 and 150–189 minutes/week for primary and secondary schools, respectively) or high (≥150 and ≥190 minutes/week for primary and secondary schools, respectively) compulsory physical activity schools by tertile cutpoints. 6,412 children reported frequency and duration of school (PE and sport) and non-school (commuting and non-organised exercise) physical activity and had height and weight measured; overweight was defined using body mass index (BMI) (m/kg²) cutpoints. 9, 12 and 15 year-olds (n = 2,595) completed a cycle ergometer fitness test (physical working capacity at heart rate 170, PWC₁₇₀). At follow-up in 2004–5, 2,346 participants kept a pedometer record, completed the International Physical Activity Questionnaire and/or a PWC₁₇₀ fitness test; and had height and weight measured (overweight = BMI≥25 m/kg²).

Results

At baseline and follow-up, median total physical activity, fitness and BMI were similar in participants who attended low, medium and high physical activity schools, and those attending high physical activity schools reported only modestly higher school physical activity. There was no difference in the prevalence of high total physical activity and fitness levels in childhood or adulthood across compulsory school physical activity categories. The prevalence of overweight in childhood and adulthood was similar across low, medium and high compulsory physical activity schools.

Conclusion

The amount of compulsory physical activity reported by schools was not associated with total physical activity, fitness or overweight in childhood or in adulthood. Policies promoting amounts of compulsory school physical activity in this range may not be sufficient to increase physical activity and fitness or reduce the prevalence of obesity in children.

The contribution of physical activity and sedentary behaviours to the growth and development of children and adolescents: implications for overweight and obesity

The obesity epidemic is a global trend and is of particular concern in children. Recent reports have highlighted the severity of obesity in children by suggesting: "today's generation of children will be the first for over a century for whom life expectancy falls." This review assesses the evidence that identifies the important role of physical activity in the growth, development and physical health of young people, owing to its numerous physical and psychological health benefits. Key issues, such as "does a sedentary lifestyle automatically lead to obesity" and "are levels of physical activity in today's children less than physical activity levels in children from previous generations?", are also discussed.Today's environment enforces an inactive lifestyle that is likely to contribute to a positive energy balance and childhood obesity. Whether a child or adolescent, the evidence is conclusive that physical activity is conducive to a healthy lifestyle and prevention of disease. Habitual physical activity established during the early years may provide the greatest likelihood of impact on mortality and longevity. It is evident that environmental factors need to change if physical activity strategies are to have a significant impact on increasing habitual physical activity levels in children and adolescents. There is also a need for more evidence-based physical activity guidelines for children of all ages. Efforts should be concentrated on facilitating an active lifestyle for children in an attempt to put a stop to the increasing prevalence of obese children.

Metabolic and behavioral compensatory responses to exercise interventions: barriers to weight loss

An activity-induced increase in energy expenditure theoretically disturbs energy balance (EB) by creating an acute energy deficit. Compensatory responses could influence the weight loss associated with the energy deficit. Individual variability in compensation for perturbations in EB could partly explain why some individuals fail to lose weight with exercise. It is accepted that the regulatory system will readily defend impositions that promote a negative EB. Therefore, a criticism of exercise interventions is that they will be ineffective and futile methods of weight control because the acute energy deficit is counteracted. Compensation for exercise-induced energy deficits can be categorized into behavioral or metabolic responses and automatic or volitional. An automatic compensatory response is a biological inevitability and considered to be obligatory. An automatic compensatory response is typically a metabolic consequence (e.g., reduced resting metabolic rate) of a negative EB. In contrast, a volitional compensatory response tends to be deliberate and behavioral, which the individual intentionally performs (e.g., increased snack intake). The purpose of this review is to highlight the various metabolic and behavioral compensatory responses that could reduce the effectiveness of exercise and explain why some individuals experience a lower than expected weight loss. We propose that the extent and degree of compensation will vary between individuals. That is, some individuals will be predisposed to compensatory responses that render them resistant to the weight loss benefits theoretically associated with an exercise-induced increase in energy expenditure. Therefore, given the inter-individual variability in behavioral and metabolic compensatory responses, exercise prescriptions might be more effective if tailored to suit individuals.

The aetiology of childhood obesity: a review

Whilst the prevention of childhood obesity is the only viable, enduring, cost-effective solution to the obesity epidemic, effective methods for it remain elusive. Furthermore, strategies to influence obesogenic environments remain relatively unexplored. In order to be able to develop powerful population-level interventions and public health policies to prevent childhood obesity, it is important to understand its aetiology and those environments that are most amenable to measurable change. First, the present paper considers why we should be concerned about obesity in children, from both the perspective of the increased health risk to the individual and the high economic cost of treatment of obesity and related diseases, highlighting why the prevention of childhood obesity is important. Next, the determinants of health behaviour and the obesogenic environment are explored, which helps us to understand why the aetiology is so complex and that potential causal factors should not be considered in isolation, as the interaction between these factors is also important. The paper then considers the multi-factorial aetiology of childhood obesity and the rationale for the increasing trends in obesity that are evident, in order to understand what is changing in society and our children's behaviour that is triggering the positive energy balance leading to obesity. The review emphasises the need for multi-level approaches if we truly want to prevent childhood obesity. It also serves to highlight that there is a need to extend the current research base in order to build a well-founded framework to form the basis of a strategy for the prevention of childhood obesity.

Children's physical activity levels during school recess: a quasi-experimental intervention study

Background

Recess provides a daily opportunity for children to engage in moderate-to-vigorous (MVPA) and vigorous physical activity (VPA). Limited research has investigated the effects of recess-based interventions on physical activity using large sample sizes whilst investigating variables that may influence the intervention effect. The aim of the study was to investigate the short-term effects of a playground markings and physical structures intervention on recess physical activity. A secondary aim was to investigate the effects of covariates on the intervention.

Methods

150 boys and 147 girls were randomly selected from 26 elementary schools to wear uni-axial accelerometers that quantified physical activity every 5 seconds during recess. Fifteen schools located in deprived areas in one large urban city in England received funding through a national initiative to redesign the playground environment. Eleven schools served as matched socioeconomic controls. Data were collected at baseline and 6-weeks following playground intervention. Recess MVPA and VPA levels adjusted for pupil- and school-level covariates (baseline physical activity, age, gender, recess length, body mass index) were analysed using multilevel analyses.

Results

Positive but non-significant intervention effects were found for MVPA and VPA when confounding variables were added to the model. Gender was a significant predictor of recess physical activity, with boys engaging in more MVPA and VPA than girls. Significant interactions for MVPA revealed that the intervention effect was stronger for younger elementary aged school children compared to older children, and the intervention effect increased as daily recess duration increased.

Conclusion

The playground redesign intervention resulted in small but non-significant increases in children's recess physical activity when school and pupil level variables were added to the analyses. Changing the playground environment produced a stronger intervention effect for younger children, and longer daily recess duration enabled children to engage in more MVPA following the intervention. This study concludes that the process of increasing recess physical activity is complex when school and pupil-level covariates are considered, though they should be taken into account when investigating the effects of playground intervention studies on children's physical activity during recess.

Policy options for responding to the growing challenge from obesity in the United Kingdom

The aim of this study was to map and analyse how key stakeholders evaluated options for dealing with the rising incidence of obesity in the UK, as part of a wider cross-national study in nine European countries. Multi-criteria mapping was used to capture the ways in which different policy options were evaluated by a variety of key stakeholders. 'Positive societal benefits' was among the criteria most often selected by participants to assess the options and was generally considered more important than costs. Of the seven pre-defined options that all participants appraised, those related to increasing opportunities for physical activity received the highest rankings, and fiscal measures the lowest. Educational measures fared best among the remaining 13 discretionary options while technological measures performed poorly. No one option, or group of options, was considered sufficient to address the obesity problem. Rather, a general consensus was evident in support of mutually reinforcing measures related to education, information, healthier food and physical activity. Although obesity policies are currently emerging in these different areas in the UK, there is a need for them to be better coordinated, and for improved surveillance to estimate their effectiveness in reversing the trend in obesity.

The physical activity patterns of European youth with reference to methods of assessment

This article reviews the habitual physical activity of children and adolescents from member countries of the European Union in relation to methods of assessing and interpreting physical activity. Data are available from all European Union countries except Luxembourg and the trends are very similar. European boys of all ages participate in more physical activity than European girls and the gender difference is more marked when vigorous activity is considered. The physical activity levels of both genders are higher during childhood and decline as young people move through their teen years. Physical activity patterns are sporadic and sustained periods of moderate or vigorous physical activity are seldom achieved by many European children and adolescents. Expert committees have produced guidelines for health-related physical activity for youth but they are evidence-informed rather than evidence-based and where there is evidence of a relationship between physical activity during youth and health status there is little evidence of a particular shape of that relationship. The number of children who experience physical activity of the duration, frequency and intensity recommended by expert committees decreases with age but accurate estimates of how many girls and boys are inactive are clouded by methodological problems. If additional insights into the promotion of health through habitual physical activity during youth are to be made, methods of assessment need to be further refined and recommended guidelines re-visited in relation to the existing evidence base.

Trends in physical activity and sedentary behaviour in adolescence: ethnic and socioeconomic differences

OBJECTIVE

To assess developmental trends in physical activity and sedentary behaviour in British adolescents in relation to sex, ethnicity and socioeconomic status (SES).

DESIGN

A 5-year longitudinal study of a diverse cohort of students aged 11-12 years at baseline in 1999.

SETTING

36 London schools sampled using a stratified random sampling procedure.

PARTICIPANTS

A total of 5863 students categorised as white, black or Asian, and stratified for SES using the Townsend Index.

MAIN OUTCOME MEASURES

Number of days per week of vigorous activity leading to sweating and breathing hard. Hours of sedentary behaviour, including watching television and playing video games. Data were analysed using multilevel, linear, mixed models.

RESULTS

Marked reductions in physical activity and increases in sedentary behaviour were noticed between ages 11-12 and 15-16 years. Boys were more active than girls, and the decline in physical activity was greater in girls (46% reduction) than in boys (23%). Asian students were less active than whites, and this was also true of black girls but not boys. Black students were more sedentary than white students. Levels of sedentary behaviour were greater in respondents from lower SES. Most differences between ethnic and SES groups were present at age 11 years, and did not evolve over the teenage years.

CONCLUSIONS

Physical activity declines and sedentary behaviour becomes more common during adolescence. Ethnic and SES differences are observed in physical activity and sedentary behaviour in British youth that anticipate adult variations in adiposity and cardiovascular disease risk. These are largely established by age 11-12 years, so reversing these patterns requires earlier intervention.

Determinants of sufficient daily activity in Australian primary school children

AIMS

Australian guidelines recommend that children participate in at least one hour of physical activity every day. We aimed to measure physical activity participation in a random sample of Australian primary school children and to determine the biological, behavioural, environmental and social influences associated with insufficient daily activity.

METHOD

We analysed the following cross-section data from a randomly selected sample of children (N=518) aged 5 to 12 years: age, gender, socioeconmic status (SES) indicators, family size, home play equipment availability, transport method to school, and estimated time per week in physical and sedentary activity. Logistic regression analysis was performed to determine variables that were associated with insufficient (<60 minutes) daily activity.

RESULTS

Seventy-six children (15% of the cohort) failed to meet the minimum activity recommendations of 60 minutes of daily activity. These children were significantly less likely to walk or cycle to school (adjusted odds ratio (OR) 0.43; 95% CI=0.24-0.77) or participate in organised sports or activity (OR 0.42; 95% CI=0.28-0.64) and were more likely to spend in excess of 2 hours a day watching television of using a computer for entertainment (OR 2.10 (1.16-3.78). Age, gender, SES and family size were not significantly associated with insufficient activity.

CONCLUSION

There exists a significant proportion of the paediatric population who are insufficiently active. Interventions to encourage increased activity in this sub-group may be successful if they seek to alter sedentary behaviour (namely television use) and method of transportation to and from school.

Variation in physical activity lies with the child, not his environment: evidence for an ‘activitystat’ in young children (EarlyBird 16)

OBJECTIVE

There is currently wide interest in the physical activity of children, but little understanding of its control. Here, we use accelerometers to test the hypothesis that habitual activity in young children is centrally, rather than environmentally, regulated. By central regulation we mean a classic biological feedback loop, with a set-point individual to the child, which controls his/her activity independently of external factors.

DESIGN

Non-intervention, observational and population-based, set in the home and at school.

RESULTS

Girls were systematically less active than boys, and both weekday/weekend day and year-on-year activities were correlated (r=0.43-0.56). A fivefold variation in timetabled PE explained less than 1% of the total variation in physical activity. The activity cost of transport to school was only 2% of total activity, but over 90% of it was recovered elsewhere in the day. The weekly activity recorded by children in Plymouth was the same (to within <0.3%) as that recorded independently in Glasgow, 800 km away. Total daily activity was unrelated to time reportedly spent watching TV.

INTERPRETATION

The correlations within groups and the similarities between them suggest that physical activity in children is under central biological regulation. There are implications both for public health planners and for the potentially novel signalling pathways involved.

Estimating the effects of energy imbalance on changes in body weight in children

BACKGROUND

Estimating changes in weight from changes in energy balance is important for predicting the effect of obesity prevention interventions.

OBJECTIVE

The objective was to develop and validate an equation for predicting the mean weight of a population of children in response to a change in total energy intake (TEI) or total energy expenditure (TEE).

DESIGN

In 963 children with a mean (+/-SD) age of 8.1 +/- 2.8 y (range: 4-18 y) and weight of 31.5 +/- 17.6 kg, TEE was measured by using doubly labeled water. Log weight (dependent variable) and log TEE (independent variable) were analyzed in a linear regression model with height, age, and sex as covariates. It was assumed that points of dynamic balance, called "settling points," occur for populations wherein energy is in balance (TEE = TEI), weight is stable (ignoring growth), and energy flux (EnFlux) equals TEE.

RESULTS

TEE (or EnFlux) explained 74% of the variance in weight. The unstandardized regression coefficient was 0.45 (95% CI: 0.38, 0.51; R(2) = 0.86) after including covariates. Conversion into proportional changes (time(1) to time(2)) gave the equation (weight(2)/weight(1)) = (EnFlux(2)/EnFlux(1))(0.45). In 3 longitudinal studies (n = 212; mean follow-up of 3.4 y), the equation predicted the mean follow-up measured weight to within 0.5%.

CONCLUSIONS

The relation of EnFlux with weight was positive, which implied that a high TEI (rather than low physical activity and low TEE) was the main determinant of high body weight. Two populations of children with a 10% difference in mean EnFlux would have a 4.5% difference in mean weight.

Behavioural determinants of obesity

Obesity in children arises from a complex interplay between genetic susceptibility and behaviour, primarily relating to dietary habits and physical activity. Evidence for specific behavioural factors that promote or protect against excess weight gain in children is more limited than in adults, and the effects of growth and development are not clear. A number of behavioural risk factors has been postulated, including diets with a high energy density, high consumption of sugar-sweetened beverages, large portion sizes, eating patterns, high levels of sedentary behaviour and low levels of physical activity. However, most evidence is derived from cross-sectional studies which frequently yield conflicting results. More prospective studies with accurate measures of exposures and outcomes in terms of body composition are needed to provide more robust evidence on which to base interventions to achieve long-term behavioural change and prevent excess weight gains in children.

Active commuting to and from school and BMI in elementary school children-preliminary data

BACKGROUND

United States National Health Objectives include increasing the proportion of trips made by walking to and from school for children who live within 1.6 km to 50%. The purpose of this objective is to increase the level of physical activity among children. However, the impact of walking, bicycling or skating (active commuting) to and from school on the prevalence of overweight is unknown.

METHODS

Body mass index (BMI) was measured for 320 children (age 10.2+/-0.7 years) in September. Over 5 months, an active commuting index (SI) and daily physical activity were estimated via questionnaire. In April, BMI and body fat were measured.

RESULTS

A significant positive association was found between April BMI and SI adjusting for September BMI (partial r=0.03, P<0.05). Positive associations were found between SI and physical activity before school (r=0.17, P<0.05) and daily moderate intensity physical activity (r=0.13, P<0.05). There were no significant association between SI and BF (P>0.05).

CONCLUSIONS

This preliminary data suggests that active commuting does not appear to provide sufficient amounts of physical activity to attenuate BMI; however, it may contribute to the attainment of physical activity recommendations. Future research is needed to objectively measure the impact of active commuting on the prevalence of overweight.