Pedometer determined physical activity levels in primary school children from central England

Full-Day Physical Activity and Sedentary Behaviour Levels of Typically Developing Children and Adolescents in the Middle East: A Systematic Review

Physical activity (PA) and sedentary behaviour (SB) are important components of physical behaviour associated with long-term health outcomes. Environmental and cultural factors may influence physical behaviour. To explore full day PA and SB in children and adolescents (2-18 years old) in the Middle East, a systematic literature review was performed including 183 journal articles. A wide range of PA and SB outcomes were reported, in some cases making synthesis of results difficult. As a consequence, results were generally reported narratively (MVPA time, total PA, SB time). Meta-regression of daily step count revealed females took 4600 fewer steps than males, with 3000 fewer steps on weekdays than weekends, and overweight individuals taking 2800 fewer steps/day. Steps decreased with age. Meta-regression for TV viewing time demonstrated an increase by 0.04 h per year of age. Even though environmental and cultural conditions may be different, PA and SB of children and adolescents in the Middle East were largely comparable to those of Europeans and North Americans. The wide range of data collection instruments used (both self-report questionnaire and body-worn devices) and heterogeneity of data made synthesis of reported data across studies very difficult, suggesting a need for greater standardisation of data collection methods.

Children's Perceived and Actual Physical Activity Levels within the Elementary School Setting

To date, little research has longitudinally examined young children’s physical activity (PA) during school hours, nor questioned children’s perceptions of their own PA behaviours. This study investigated 20 children’s actual physical activity levels (APA) and their perceived physical activity levels (PPA) (10 infants, mean age 6.6 years; 10 juniors, mean age 9.5 years). APA was evaluated using accelerometers across 36 whole school days (371 min per day); 18 days included Physical Education (PE) lessons and 18 did not. A repeated-measures three-factor ANOVA analysed: type of day; age phase; parts of the day and sex. PPA was collected by an interactive handset and an adapted version of the PA Questionnaire for Children (PAQ-C). Participants undertook 10 more minutes of moderate to vigorous PA (MVPA) on PE days (53 ± 19 min) compared to non-PE days (43 ± 15 min) (F = 92.32, p < 0.05) and only junior boys reached daily MVPA recommendations (60 ± 13 min) on PE days. Juniors over-estimated, and infants under-estimated, their APA levels. Educators need more support to teach and embed different PA intensities into the school day to enable children to better understand the health benefits associated with varying the intensity of their PA during school hours.

Four Minutes of Sprint Interval Training Had No Acute Effect on Improving Alertness, Mood, and Memory of Female Primary School Children and Secondary School Adolescents: A Randomized Controlled Trial

We investigated whether a 4-min sprint interval training (SIT) protocol had an acute effect (15 min after) on improving alertness, mood, and memory recall in female students. Sixty-three children and 131 adolescents were randomly assigned to either a SIT or control (CON) group by the class Physical Education (PE) teachers. The SIT intervention was delivered twice a week for 3 weeks. SIT participants performed three, 20-s 'all-out' effort sprints interspersed with 60-s intervals of walking while CON group sat down and rested. PE lessons were arranged such that the first two sessions were to familiarise participants with the SIT protocol leading to acute assessments conducted on the third session. On that occasion, both groups rated their alertness and mood on a single-item hedonic scale and underwent an adapted memory recall test. The same assessments were administered to both groups fifteen minutes after delivery of SIT intervention. A 4-min SIT involving three, 20 s 'all-out' effort intensity sprints did not have an acute main effect on improving alertness, mood and, memory recall in female children (η_p² = 0.009) and adolescents (η_p² = 0.012). Students' exercise adherence and feedback from PE teachers are indicatives of the potential scalability of incorporating SIT into PE programmes. Different work-to-rest ratios could be used in future studies.

Weekly variation in diet and physical activity among 4-75-year-old Danes

OBJECTIVE

To compare dietary intake and physical activity (PA) between days of the week in a large sample of the Danish population; furthermore, to investigate the influence of gender and age as determinants for weekly variation.

DESIGN

Analysis was based on cross-sectional data from the Danish National Survey of Diet and Physical Activity 2011-2013. Dietary intake and PA were assessed by 7 d of pre-coded food diaries and pedometer-determined step counts. Dietary intake and PA on weekdays (Monday-Thursday), Friday, and weekend days (Saturday and Sunday) were compared using linear mixed models.

SETTING

Survey with national representation, conducted in Denmark between 2011 and 2013.

PARTICIPANTS

A random sample of 4-75-year-old Danes, n 3934 and n 3530 in analysis of dietary intake and PA, respectively.

RESULTS

Energy intake during Friday and weekend days was 7-20 % higher compared with weekdays, while step counts were 10 and 17 % lower on Saturday and Sunday, respectively (all P < 0·001). Energy density of liquids and solids, consumption of added sugar, alcohol, discretionary foods, beer, wine and sugar-sweetened beverages were substantially higher, and consumption of dietary fibre, vegetables, fruit and wholegrain products were lower, during Friday and weekend days compared with weekdays (all P < 0·001). The observed patterns were present across gender and age, although weekly variation was most pronounced among children and relatively modest among the elderly.

CONCLUSIONS

Weekend health behaviours of Danes display less favourable eating and PA behaviour compared with weekdays, making the weekend an important target for public health interventions aiming to improve dietary intake and PA behaviour.

Validating Fitbit Zip for monitoring physical activity of children in school: a cross-sectional study

Background

Modern activity trackers, including the Fitbit Zip, enable the measurement of both the step count as well as physical activity (PA) intensities. However, there is a need for field-based validation studies in a variety of populations before using trackers for research. Therefore, the purpose of the current study was to investigate the validity of Fitbit Zip step count, moderate to vigorous physical activity (MVPA) and sedentary minutes, in different school segments in 3rd grade students.

Methods

Third grade students (N = 147, aged 9–10 years) wore a Fitbit Zip and an ActiGraph GT3x-BT accelerometer simultaneously on a belt for five days during school hours. The number of steps, minutes of MVPA and sedentary time during class time, physical education lessons and recess were extracted from both devices using time filters, based on the information from school time tables obtained from class teachers. The validity of the Fitbit Zip in different school segments was assessed using Bland-Altman analysis and Spearman’s correlation.

Results

There was a strong correlation in the number of steps in all in-school segments between the two devices (r = 0.85–0.96, P < 0.001). The Fitbit Zip overestimated the number of steps in all segments, with the greatest overestimation being present in physical education lessons (345 steps). As for PA intensities, the agreement between the two devices in physical education and recess was moderate for MVPA minutes (r = 0.56 and r = 0.72, P < 0.001, respectively) and strong for sedentary time (r = 0.85 and r = 0.87, P < 0.001, respectively). During class time, the correlation was weak for MVPA minutes (r = 0.24, P < 0.001) and moderate for sedentary time (r = 0.57, P < 0.001). For total in-school time, the correlation between the two devices was strong for steps (r = 0.98, P < 0.001), MVPA (r = 0.80, P < 0.001) and sedentary time (r = 0.94, P < 0.001).

Conclusion

In general, the Fitbit Zip can be considered a relatively accurate device for measuring the number of steps, MVPA and sedentary time in students in a school-setting. However, in segments where sedentary time dominates (e.g. academic classes), a research-grade accelerometer should be preferred.

Understanding differences between summer vs. school obesogenic behaviors of children: the structured days hypothesis

BACKGROUND

Although the scientific community has acknowledged modest improvements can be made to weight status and obesogenic behaviors (i.e., physical activity, sedentary/screen time, diet, and sleep) during the school year, studies suggests improvements are erased as elementary-age children are released to summer vacation. Emerging evidence shows children return to school after summer vacation displaying accelerated weight gain compared to the weight gained occurring during the school year. Understanding how summer days differ from when children are in school is, therefore, essential.

DISCUSSION

There is limited evidence on the etiology of accelerated weight gain during summer, with few studies comparing obesogenic behaviors on the same children during school and summer. For many children, summer days may be analogous to weekend days throughout the school year. Weekend days are often limited in consistent and formal structure, and thus differ from school days where segmented, pre-planned, restrictive, and compulsory components exist that shape obesogenic behaviors. The authors hypothesize that obesogenic behaviors are beneficially regulated when children are exposed to a structured day (i.e., school weekday) compared to what commonly occurs during summer. This is referred to as the 'Structured Days Hypothesis' (SDH). To illustrate how the SDH operates, this study examines empirical data that compares weekend day (less-structured) versus weekday (structured) obesogenic behaviors in U.S. elementary school-aged children. From 190 studies, 155 (~80%) demonstrate elementary-aged children's obesogenic behaviors are more unfavorable during weekend days compared to weekdays.

CONCLUSION

In light of the SDH, consistent evidence demonstrates the structured environment of weekdays may help to protect children by regulating obesogenic behaviors, most likely through compulsory physical activity opportunities, restricting caloric intake, reducing screen time occasions, and regulating sleep schedules. Summer is emerging as the critical period where childhood obesity prevention efforts need to be focused. The SDH can help researchers understand the drivers of obesogenic behaviors during summer and lead to innovative intervention development.

Measuring the Daily Activity of Lying Down, Sitting, Standing and Stepping of Obese Children Using the ActivPALTM Activity Monitor

This study describes the patterns of objectively measured sitting, standing and stepping in obese children using the activPALTM and highlights possible differences in sedentary levels and patterns during weekdays and weekends. Sixty-five obese children, aged 9-11 years, were recruited from primary schools in Terengganu, Malaysia. Sitting, standing and stepping were objectively measured using an activPALTM accelerometer over a period of 4-7 days. Obese children spent an average of 69.6% of their day sitting/lying, 19.1% standing and 11.3% stepping. Weekdays and weekends differed significantly in total time spent sitting/lying, standing, stepping, step count, number of sedentary bouts and length of sedentary bouts (p < 0.05, respectively). Obese children spent a large proportion of their time sedentarily, and they spent more time sedentarily during weekends compared with weekdays. This study on sedentary behaviour patterns presents valuable information for designing and implementing strategies to decrease sedentary time among obese children, particularly during weekends.

Physical activity is low in obese New Zealand children and adolescents

We aimed to describe physical activity and sedentary behaviour of obese children and adolescents in Taranaki, New Zealand, and to determine how these differ in Māori (indigenous) versus non-indigenous children. Participants (n = 239; 45% Māori, 45% New Zealand European [NZE], 10% other ethnicities) aged 4.8–16.8 years enrolled in a community-based obesity programme from January 2012 to August 2014 who had a body mass index (BMI) ≥ 98^th percentile (n = 233) or >91^st–98^th percentile with weight-related comorbidities (n = 6) were assessed. Baseline activity levels were assessed using the children’s physical activity questionnaire (C-PAQ), a fitness test, and ≥3 days of accelerometer wear. Average BMI standard deviation score was 3.09 (SD = 0.60, range 1.52–5.34 SDS). Reported median daily activity was 80 minutes (IQR = 88). Although 44% of the cohort met the national recommended screen time of <2 hours per day, the mean screen time was longer at 165 minutes (SD = 135). Accelerometer data (n = 130) showed low physical activity time (median 34 minutes [IQR = 29]). Only 18.5% of the total cohort met national recommended physical activity guidelines of 60 minutes per day. There were minimal ethnic differences. In conclusion, obese children/adolescents in this cohort had low levels of physical activity. The vast majority are not meeting national physical activity recommendations.

levels and sociodemographic correlates of accelerometer-based physical activity in Irish children: a cross-sectional study

BACKGROUND

The aim of this study was to explore levels and sociodemographic correlates of physical activity (PA) over 1 week using accelerometer data.

METHODS

Accelerometer data was collected over 1 week from 1075 8-11-year-old children in the cross-sectional Cork Children's Lifestyle Study. Threshold values were used to categorise activity intensity as sedentary, light, moderate or vigorous. Questionnaires collected data on demographic factors. Smoothed curves were used to display minute by minute variations. Binomial regression was used to identify factors correlated with the probability of meeting WHO 60 min moderate to vigorous PA guidelines.

RESULTS

Overall, 830 children (mean (SD) age: 9.9(0.7) years, 56.3% boys) were included. From the binomial multiple regression analysis, boys were found more likely to meet guidelines (probability ratio 1.17, 95% CI 1.06 to 1.28) than girls. Older children were less likely to meet guidelines than younger children (probability ratio 0.91, CI 0.87 to 0.95). Normal weight children were more likely than overweight and obese children to meet guidelines (probability ratio 1.25, CI 1.16 to 1.34). Children in urban areas were more likely to meet guidelines than those in rural areas (probability ratio 1.19, CI 1.07 to 1.33). Longer daylight length days were associated with greater probability of meeting guidelines compared to shorter daylight length days.

CONCLUSIONS

PA levels differed by individual factors including age, gender and weight status as well as by environmental factors including residence and daylight length. Less than one-quarter of children (26.8% boys, 16.2% girls) meet guidelines. Effective intervention policies are urgently needed to increase PA.

Systematic review to identify and appraise outcome measures used to evaluate childhood obesity treatment interventions (CoOR): evidence of purpose, application, validity, reliability and sensitivity

BACKGROUND

Lack of uniformity in outcome measures used in evaluations of childhood obesity treatment interventions can impede the ability to assess effectiveness and limits comparisons across trials.

OBJECTIVE

To identify and appraise outcome measures to produce a framework of recommended measures for use in evaluations of childhood obesity treatment interventions.

DATA SOURCES

Eleven electronic databases were searched between August and December 2011, including MEDLINE; MEDLINE In-Process and Other Non-Indexed Citations; EMBASE; PsycINFO; Health Management Information Consortium (HMIC); Allied and Complementary Medicine Database (AMED); Global Health, Maternity and Infant Care (all Ovid); Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost); Science Citation Index (SCI) [Web of Science (WoS)]; and The Cochrane Library (Wiley) - from the date of inception, with no language restrictions. This was supported by review of relevant grey literature and trial databases.

REVIEW METHODS

Two searches were conducted to identify (1) outcome measures and corresponding citations used in published childhood obesity treatment evaluations and (2) manuscripts describing the development and/or evaluation of the outcome measures used in the childhood intervention obesity evaluations. Search 1 search strategy (review of trials) was modelled on elements of a review by Luttikhuis et al. (Oude Luttikhuis H, Baur L, Jansen H, Shrewsbury VA, O'Malley C, Stolk RP, et al. Interventions for treating obesity in children. Cochrane Database Syst Rev 2009;1:CD001872). Search 2 strategy (methodology papers) was built on Terwee et al.'s search filter (Terwee CB, Jansma EP, Riphagen II, de Vet HCW. Development of a methodological PubMed search filter for finding studies on measurement properties of measurement instruments. Qual Life Res 2009;18:1115-23). Eligible papers were appraised for quality initially by the internal project team. This was followed by an external appraisal by expert collaborators in order to agree which outcome measures should be recommended for the Childhood obesity Outcomes Review (CoOR) outcome measures framework.

RESULTS

Three hundred and seventy-nine manuscripts describing 180 outcome measures met eligibility criteria. Appraisal of these resulted in the recommendation of 36 measures for the CoOR outcome measures framework. Recommended primary outcome measures were body mass index (BMI) and dual-energy X-ray absorptiometry (DXA). Experts did not advocate any self-reported measures where objective measurement was possible (e.g. physical activity). Physiological outcomes hold potential to be primary outcomes, as they are indicators of cardiovascular health, but without evidence of what constitutes a minimally importance difference they have remained as secondary outcomes (although the corresponding lack of evidence for BMI and DXA is acknowledged). No preference-based quality-of-life measures were identified that would enable economic evaluation via calculation of quality-adjusted life-years. Few measures reported evaluating responsiveness.

LIMITATIONS

Proposed recommended measures are fit for use as outcome measures within studies that evaluate childhood obesity treatment evaluations specifically. These may or may not be suitable for other study designs, and some excluded measures may be more suitable in other study designs.

CONCLUSIONS

The CoOR outcome measures framework provides clear guidance of recommended primary and secondary outcome measures. This will enhance comparability between treatment evaluations and ensure that appropriate measures are being used. Where possible, future work should focus on modification and evaluation of existing measures rather than development of tools de nova. In addition, it is recommended that a similar outcome measures framework is produced to support evaluation of adult obesity programmes.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Pedometer-determined physical activity patterns in a segmented school day among Hong Kong primary school children

Background/Objective

This study aimed to characterize pedometer-determined physical activity (PA) patterns in segmented school days among Hong Kong primary school children.

Methods

Participants were instructed to wear pedometers for 4 consecutive days. The overall step counts and counts at specific periods (e.g., after school, recess, and lunch) during the test days were recorded.

Results

Of the 74 recruited participants, 68 (41.2% boys, aged 10 and 11 years old) provided valid data. The mean total daily steps over the 4 test days ranged from 9064 to 9714 (standard deviation = 3140-3471 steps). The periods that contributed most toward total daily steps were after school (34.2%), recess (14.0%), and physical education (PE) classes (12.3%). Overall, Student t tests revealed that boys were more active than girls. More active children (daily step average above the sex-specific median value) accumulated significantly more steps during recess and after school than less active children (daily step average below the sex-specific median value) in both sexes (mean differences ranged from 507 steps to 1977 steps). A mixed model analysis of variance (ANOVA) revealed that students accumulated 914 steps more on days that included PE classes than on days without PE classes. A three-way ANOVA found no significant differences in body weight status (normal weight vs. overweight and obesity) and travel mode (active vs. passive modes).

Conclusion

The findings provide a better understanding of PA patterns and the contribution of the distinct segments within a school day to children's PA. This information may assist in developing more effective, appropriate, and timely school-based PA interventions for children in Hong Kong.

Framework of outcome measures recommended for use in the evaluation of childhood obesity treatment interventions: the CoOR framework

INTRODUCTION

Consensus is lacking in determining appropriate outcome measures for assessment of childhood obesity treatments. Inconsistency in the use and reporting of such measures impedes comparisons between treatments and limits consideration of effectiveness. This study aimed to produce a framework of recommended outcome measures: the Childhood obesity treatment evaluation Outcomes Review (CoOR) framework.

METHODS

A systematic review including two searches was conducted to identify (1) existing trial outcome measures and (2) manuscripts describing development/evaluation of outcome measures. Outcomes included anthropometry, diet, eating behaviours, physical activity, sedentary time/behaviour, fitness, physiology, environment, psychological well-being and health-related quality of life. Eligible measures were appraised by the internal team using a system developed from international guidelines, followed by appraisal from national external expert collaborators.

RESULTS

A total of 25,486 papers were identified through both searches. Eligible search 1 trial papers cited 417 additional papers linked to outcome measures, of which 56 were eligible. A further 297 outcome development/evaluation papers met eligibility criteria from search 2. Combined, these described 191 outcome measures. After internal and external appraisal, 52 measures across 10 outcomes were recommended for inclusion in the CoOR framework.

CONCLUSION

Application of the CoOR framework will ensure greater consistency in choosing robust outcome measures that are appropriate to population characteristics.

Pedometers and participatory school-based health education – an exploratory study

Purpose

– The purpose of this paper is to explore how pedometers (simple gadgets that count steps) can be used as tools in participatory health education to enhance primary school children's insights into, and abilities to reflect on, physical activity in their daily life. The paper focuses on how using pedometers fosters participation and enhances reflection concerning physical activity.

Design/methodology/approach

– The paper draws on findings from an exploratory project with sixth-grade classes (12-13 years) in four Danish primary schools. The approach is called Imove. In Imove, pupils use pedometers to study their own patterns of physical activity, transform their data into statistics, and use the statistical representation to reflect on how physical activity is integrated into everyday life patterns, and how different activities constitute an active life.

Findings

– The paper concludes that pedometers support pupils’ participation in studying their own health practices, and the step data provide new insights into, and encourage pupils to reflect on, the way physical activity is formed into everyday patterns.

Research limitations/implications

– The study is an exploratory one with four participating school classes. The findings need to be further explored by employing similar methodology in studies with more participants. Nevertheless, there is no doubt that pedometers support pupils’ genuine participation in health educational processes.

Practical implications

– The findings identify simple measuring technologies, such as pedometers, as potent assets in health education learning processes and call for creative thinking in developing health promotion programmes for young people.

Originality/value

– Measuring technologies play an increasingly critical role in health research, as well as in individual health regulating practices. This paper contributes with a new perspective by demonstrating the educational possibilities of applying pedometers in participatory school health education.

Pedometer determined physical activity and obesity prevalence of Greek children aged 4-6 years

BACKGROUND

Pre-school age is important for developing healthy attitudes towards physical activity (PA). However, research on pre-schoolers' pedometer-determined PA is limited.

AIM

To describe pre-schoolers' ambulatory activity; investigate step count differences in respect to Body Mass Index (BMI) categories and examine the prevalence of obesity.

SUBJECTS AND METHODS

Pre-school aged children (n = 250; 5.5 ± 0.4 years) from Komotini (Greece) wore Omron HJ-720IT-E2 pedometers for 10 consecutive days. Height and weight were measured and BMI was calculated.

RESULTS

Three-way repeated measures ANOVAs revealed that children performed more steps on weekdays than during weekends (p < 0.001) and during leisure time than school (p < 0.001). Significant differences appeared between normal and obese children's counts on weekdays (p < 0.001), weekend days (p < 0.05), during school (p < 0.001), after school (p < 0.005) and in weekly steps (p < 0.005). No gender differences were detected. Moreover, according to a sample t-test analysis, children's daily steps were significantly different from the 10,000 steps/day guideline, while obesity prevalence was 15.6%.

CONCLUSION

School-based ambulatory activity is lower than after school ambulatory activity, independent of BMI-category and gender, although obese children demonstrated fewer steps. Taking into account the high rate of both the obesity prevalence and children not meeting the 10,000 steps/day guideline, the need for preventive policies becomes obvious.

Parent-child associations in pedometer-determined physical activity and sedentary behaviour on weekdays and weekends in random samples of families in the Czech Republic

This study investigates whether more physically active parents bring up more physically active children and whether parents’ level of physical activity helps children achieve step count recommendations on weekdays and weekends. The participants (388 parents aged 35–45 and their 485 children aged 9–12) were randomly recruited from 21 Czech government-funded primary schools. The participants recorded pedometer step counts for seven days (≥10 h a day) during April–May and September–October of 2013. Logistic regression (Enter method) was used to examine the achievement of the international recommendations of 11,000 steps/day for girls and 13,000 steps/day for boys. The children of fathers and mothers who met the weekend recommendation of 10,000 steps were 5.48 (95% confidence interval: 1.65; 18.19; p < 0.01) and 3.60 times, respectively (95% confidence interval: 1.21; 10.74; p < 0.05) more likely to achieve the international weekend recommendation than the children of less active parents. The children of mothers who reached the weekday pedometer-based step count recommendation were 4.94 times (95% confidence interval: 1.45; 16.82; p < 0.05) more likely to fulfil the step count recommendation on weekdays than the children of less active mothers.

Physical activity patterns of ethnic children from low socio-economic environments within the UK

Many children fail to meet physical activity (PA) guidelines for health benefits. PA behaviours are complex and depend on numerous interrelated factors. The study aims to develop current understanding of how children from low Socio-economic environments within the UK use their surrounding built environments for PA by using advanced technology. The environment was assessed in 96 school children (7-9 years) using global positioning system (GPS) monitoring (Garmin Forerunner, 305). In a subsample of 46 children, the environment and PA were assessed using an integrated GPS and heart rate monitor. The percentage of time spent indoor, outdoor, in green and non-green environments along with time spent in moderate-to-vigorous PA (MVPA) in indoor and outdoor environments were assessed. A 2-by-2 repeated measures analysis of covariance, controlling for body mass index, BF%, assessed the environmental differences. The findings show that 42% of children from deprived wards of Coventry fail to meet PA guidelines, of which 43% was accumulated during school. Children engaged in more MVPA outdoor than indoor environments (P < 0.01) and a greater amount of time was spent in non-green environments (P < 0.01). Increased time outdoors was negatively associated with BF%. In conclusion, outdoor environments are important for health-enhancing PA and reducing fatness in deprived and ethnic children.

Cross-validation of pedometer-determined cut-points for healthy weight in British children from White and South Asian backgrounds

BACKGROUND

Evidence-based pedometer cut-points for health have not been sufficiently examined in the context of ethnicity.

OBJECTIVE

To (1) evaluate previously described steps/day cut-points in a sample of White and South Asian British primary school children and (2) use ROC analysis to generate alternative, ethnic specific, steps/day cut-offs for children.

METHODS AND PROCEDURES

Height, body mass and pedometer determined physical activity were assessed in 763 British children (357 boys and 406 girls) from White (n = 593) and South Asian (n = 170) ethnic groups, aged 8-11 years.

RESULTS

The Vincent and Pangrazi cut-points significantly predicted BMI in white (p = 0.006, Adjusted R(2 )= 0.08) and South Asian children (p = 0.039, Adjusted R(2 )= 0.078). The Tudor-Locke et al. cut-points significantly predicted BMI in White children (p = 0.0001, Adjusted R(2 )= 0.079) but not South Asian children (p < 0.05). ROC analysis indicated significant alternative cut-points in White and South Asian boys and girls (all p = 0.04 or better, Adjusted R(2 )= 0.091 for White and 0.09 for South Asian children). Subsequent cut-points associated with healthy weight, when translated to steps/day were 13,625 for White boys, 13,135 for White girls, 10,897 for South Asian boys and 10,161 for South Asian girls.

CONCLUSIONS

Previously published steps/day cut-points for healthy weight may not account for known ethnic variation in physical activity between White and South Asian children in the UK. Alternative, ethnic-specific, cut-points may be better placed to distinguish British children based on pedometer-determined physical activity.

The importance of parental beliefs and support for pedometer-measured physical activity on school days and weekend days among Canadian children

BACKGROUND

Parental influences are essential to the behaviours and physical activity of their children. Our study aimed to determine if parental beliefs and support are associated with children's pedometer measured physical activity levels on school days and weekend days.

METHODS

In the spring of 2009 and 2011, we analyzed cross-sectional data from 1,355 grade five students and parents in 30 schools in Alberta, Canada. Parents reported how much they care about exercising, how much they encourage their child to be physically active, and how frequently they engage in physical activities with their child. Physical activity was assessed from step counts obtained from time-stamped pedometers collected over nine consecutive days.

RESULTS

Increased parental encouragement was positively associated with boys' and girls' physical activity on school days (Boys: beta = 1373, 95% CI: 606, 2139; Girls: beta = 632, 95% CI: 108, 1155) and girls' physical activity on weekend days (beta = 997, 95% CI: 130, 1864). Increased parental care was positively associated with boys' physical activity on weekend days (beta = 1381, 95% CI: 85, 2676). Increased parental support and engagement was associated with an additional 632-1381 steps/day for children in this study.

CONCLUSIONS

Parental care, encouragement and engagement are associated with physical activity levels of children 10-11 years of age. Policy makers and researchers should consider the importance of targeting parents when designing strategies to promote physical activity in children. This is particularly relevant to weekends and holidays when children's activity levels are low.

Chinese city children and youth's walking behavior

PURPOSE

Although walking has been demonstrated as one of the best forms for promoting physical activity (PA), little is known about Chinese city children and youth's walking behavior. The purpose of this study was therefore to assess ambulatory PA behavior of Chinese city children and youth.

METHOD

The daily steps of 2,751 children and youth (1,415 boys, 1,336 girls; aged 9 to 17 years old, M(age) = 154.78 +/- 44.63 months) from 11 cities in China were recorded using ActiGraph GT3X accelerometers for 7 consecutive days.

RESULTS

The most active walking day was on Friday (M +/- SD = 11,183 +/- 5,130 steps), followed by Monday (M +/- SD = 10,780 +/- 4,921), Thursday (M +/- SD = 10,705 +/- 4,607), Tuesday (M +/- SD = 10,687 +/- 5,038), Wednesday (M +/- SD = 10,428 +/- 4,697), Saturday (M +/- SD = 9,734 +/- 5,582), and Sunday (M +/- SD = 9,303 +/- 5,569). Participants walked more steps during weekdays (M +/- SD = 10,615 +/- 4,411) than they did during weekend days (M +/- SD = 9,444 +/- 5,224; t = 15.71, p < .01, d = 0.34); boys walked more steps (M +/- SD = 10,847 +/- 4,322) than did girls (M +/- SD = 9,938 +/- 4,282; t = 4.92, p < .01, d = 0.22). The most active age was 11 years old in boys (M +/- SD = 12,984 +/- 4,897) and 10 years old in girls (M +/- SD = 11,745 +/- 4,721), and older children walked fewer steps. The data suggest that depending on age (9 to 17 years old), a range of 5.71% to 35.73%, 29.70% to 56.65%, and 15.96% to 47.62% boys and 22.86% to 40.14%, 29.41% to 46.26%, and 12.94% to 40.14% girls met 3 different health-related criteria for daily steps, respectively.

CONCLUSION

Boys walked more than girls walked, but a majority of the Chinese city children and youth did not meet the recommended health-related steps/day.

Adolescent pedometer protocols: examining reactivity, tampering and participants' perceptions

The aim of this study was to investigate adolescents' potential reactivity and tampering while wearing pedometers by comparing different monitoring protocols to accelerometer output. The sample included adolescents (N = 123, age range = 14-15 years) from three secondary schools in New South Wales, Australia. Schools were randomised to one of the three pedometer monitoring protocols: (i) daily sealed (DS) pedometer group, (ii) unsealed (US) pedometer group or (iii) weekly sealed (WS) pedometer group. Participants wore pedometers (Yamax Digi-Walker CW700, Yamax Corporation, Kumamoto City, Japan) and accelerometers (Actigraph GT3X+, Pensacola, USA) simultaneously for seven days. Repeated measures analysis of variance was used to examine potential reactivity. Bivariate correlations between step counts and accelerometer output were calculated to explore potential tampering. The correlation between accelerometer output and pedometer steps/day was strongest among participants in the WS group (r = 0.82, P ≤ 0.001), compared to the US (r = 0.63, P ≤ 0.001) and DS (r = 0.16, P = 0.324) groups. The DS (P ≤ 0.001) and US (P = 0.003), but not the WS (P = 0.891), groups showed evidence of reactivity. The results suggest that reactivity and tampering does occur in adolescents and contrary to existing research, pedometer monitoring protocols may influence participant behaviour.

Longitudinal patterns of physical activity in children aged 8 to 12 years: the LOOK study

BACKGROUND

Data on longitudinal monitoring of daily physical activity (PA) patterns in youth over successive years is scarce but may provide valuable information for intervention strategies aiming to promote PA.

METHODS

Participants were 853 children (starting age ~8 years) recruited from 29 Australian elementary schools. Pedometers were worn for a 7-day period each year over 5 consecutive years to assess PA volume (steps per day) and accelerometers were worn concurrently in the final 2 years to assess PA volume (accelerometer counts (AC) per day), moderate and vigorous PA (MVPA), light PA (LPA) and sedentary time (SED). A general linear mixed model was used to examine daily and yearly patterns.

RESULTS

A consistent daily pattern of pedometer step counts, AC, MVPA and LPA emerged during each year, characterised by increases on school days from Monday to Friday followed by a decrease on the weekend. Friday was the most active and Sunday the least active day. The percentage of girls and boys meeting international recommendations of 11,000 and 13,000 steps/day respectively on a Monday, Friday and Sunday were 36%, 50%, 21% for boys and 35%, 45%, 18% for girls. The equivalent percentages meeting the recommended MVPA of >60 min/day on these days were 29%, 39%, 16% for boys and 15%, 21%, 10% for girls. Over the 5 years, boys were more active than girls (mean steps/day of 10,506 vs 8,750; p<0.001) and spent more time in MVPA (mean of 42.8 vs 31.1 min/day; p<0.001). Although there was little evidence of any upward or downward trend in steps/day from age 8 to 12 years, there was a trend toward lower MVPA, LPA and a corresponding increase in SED from age 11 to 12 years.

CONCLUSION

A weekly pattern of PA occurred in children as young as age 8 on a day by day basis; these patterns persisting through to age 12. In addition to supporting previous evidence of insufficient PA in children, our data, in identifying the level and incidence of insufficiency on each day of the week, may assist in the development of more specific strategies to increase PA in community based children.

The impact of the built environment on young people's physical activity patterns: a suburban-rural comparison using GPS

The built environment in which young people live has a significant influence on their physical activity (PA). However, little is known regarding how youth from suburban and rural settings utilise their surrounding environments to participate in free-living PA. 50 adolescents aged 13–14 years old (22 rural; 28 suburban) wore an integrated GPS and heart rate device during non-school hours and completed a daily PA diary over 7 days. Descriptive statistics and analyses of variance were used to explore differences in the amount and location of moderate-to-vigorous physical activity (MVPA) between genders and youth from different geographical settings. Suburban youth participated in significantly (p = 0.004) more daily PA (52.14 minutes MVPA) and were more extensive in their utilisation of their surroundings, compared to rural youth (26.61 minutes MVPA). Suburban youth visited more public recreational facilities and spent significantly more time outdoors and on local streets (109.71 minutes and 44.62 minutes, respectively) compared to rural youth (55.98 minutes and 17.15 minutes, respectively) during weekdays. Rural youth on average spent significantly more time within the home (350.69 minutes) during weekends compared to suburban youth (214.82 minutes). Rural females were the least active group of adolescents, participating in the least amount of daily PA (20.14 minutes MVPA) and spending the least amount of time outdoors (31.37 minutes) during weekdays. Time spent outdoors was positively associated with PA. The findings highlight the disparity in PA levels and the utilisation of the surrounding built environment between youth from two different geographical settings and possible environmental causes are discussed. The study supports the use of GPS (combined with other methods) in investigating geographical differences in young people’s PA and movement patterns. This method provides a wealth of information that may assist future policies and interventions in identifying environmental characteristics that promote PA in youth from different geographical settings.

Ambulatory physical activity levels of white and South Asian children in Central England

AIMS

To assess ambulatory physical activity in white and south Asian children from Central England and to examine variation in activity between weekdays and weekends.

METHODS

536 primary school children [255 boys and 281 girls, mean age (SD) = 9.6 (1.0) years] wore a sealed pedometer for 4 days (2 weekend and 2 weekdays). Repeated measures analysis of covariance was used to examine weekend versus weekday, gender, ethnic and socio-economic status differences in steps/day controlling for age, hours of daylight and body mass index (BMI).

RESULTS

Children attained significantly higher mean steps/day during weekdays than weekends (p = 0.001) with age being more strongly associated with weekend than weekday steps/day (p = 0.014). The decline in steps/day from weekdays to weekends was greater in high compared to low socio-economic status children (p = 0.002). White children attained higher mean steps/day than south Asian children (p = 0.015). BMI was negatively associated with steps/day (p = 0.004). 39.2 and 29.9% of white and south Asian children met the BMI-referenced cut-offs for health.

CONCLUSION

Physical activity was greater during weekdays compared to weekends, was associated with BMI, age and socio-economic status and white children were more active than south Asian children.

How many steps/day are enough? for children and adolescents

Worldwide, public health physical activity guidelines include special emphasis on populations of children (typically 6-11 years) and adolescents (typically 12-19 years). Existing guidelines are commonly expressed in terms of frequency, time, and intensity of behaviour. However, the simple step output from both accelerometers and pedometers is gaining increased credibility in research and practice as a reasonable approximation of daily ambulatory physical activity volume. Therefore, the purpose of this article is to review existing child and adolescent objectively monitored step-defined physical activity literature to provide researchers, practitioners, and lay people who use accelerometers and pedometers with evidence-based translations of these public health guidelines in terms of steps/day. In terms of normative data (i.e., expected values), the updated international literature indicates that we can expect 1) among children, boys to average 12,000 to 16,000 steps/day and girls to average 10,000 to 13,000 steps/day; and, 2) adolescents to steadily decrease steps/day until approximately 8,000-9,000 steps/day are observed in 18-year olds. Controlled studies of cadence show that continuous MVPA walking produces 3,300-3,500 steps in 30 minutes or 6,600-7,000 steps in 60 minutes in 10-15 year olds. Limited evidence suggests that a total daily physical activity volume of 10,000-14,000 steps/day is associated with 60-100 minutes of MVPA in preschool children (approximately 4-6 years of age). Across studies, 60 minutes of MVPA in primary/elementary school children appears to be achieved, on average, within a total volume of 13,000 to 15,000 steps/day in boys and 11,000 to 12,000 steps/day in girls. For adolescents (both boys and girls), 10,000 to 11,700 may be associated with 60 minutes of MVPA. Translations of time- and intensity-based guidelines may be higher than existing normative data (e.g., in adolescents) and therefore will be more difficult to achieve (but not impossible nor contraindicated). Recommendations are preliminary and further research is needed to confirm and extend values for measured cadences, associated speeds, and MET values in young people; continue to accumulate normative data (expected values) for both steps/day and MVPA across ages and populations; and, conduct longitudinal and intervention studies in children and adolescents required to inform the shape of step-defined physical activity dose-response curves associated with various health parameters.

A cross-sectional study of the individual, social, and built environmental correlates of pedometer-based physical activity among elementary school children

Background

Children who participate in regular physical activity obtain health benefits. Preliminary pedometer-based cut-points representing sufficient levels of physical activity among youth have been established; however limited evidence regarding correlates of achieving these cut-points exists. The purpose of this study was to identify correlates of pedometer-based cut-points among elementary school-aged children.

Method

A cross-section of children in grades 5-7 (10-12 years of age) were randomly selected from the most (n = 13) and least (n = 12) 'walkable' public elementary schools (Perth, Western Australia), stratified by socioeconomic status. Children (n = 1480; response rate = 56.6%) and parents (n = 1332; response rate = 88.8%) completed a survey, and steps were collected from children using pedometers. Pedometer data were categorized to reflect the sex-specific pedometer-based cut-points of ≥15000 steps/day for boys and ≥12000 steps/day for girls. Associations between socio-demographic characteristics, sedentary and active leisure-time behavior, independent mobility, active transportation and built environmental variables - collected from the child and parent surveys - and meeting pedometer-based cut-points were estimated (odds ratios: OR) using generalized estimating equations.

Results

Overall 927 children participated in all components of the study and provided complete data. On average, children took 11407 ± 3136 steps/day (boys: 12270 ± 3350 vs. girls: 10681 ± 2745 steps/day; p < 0.001) and 25.9% (boys: 19.1 vs. girls: 31.6%; p < 0.001) achieved the pedometer-based cut-points.

After adjusting for all other variables and school clustering, meeting the pedometer-based cut-points was negatively associated (p < 0.05) with being male (OR = 0.42), parent self-reported number of different destinations in the neighborhood (OR 0.93), and a friend's (OR 0.62) or relative's (OR 0.44, boys only) house being at least a 10-minute walk from home. Achieving the pedometer-based cut-points was positively associated with participating in screen-time < 2 hours/day (OR 1.88), not being driven to school (OR 1.48), attending a school located in a high SES neighborhood (OR 1.33), the average number of steps among children within the respondent's grade (for each 500 step/day increase: OR 1.29), and living further than a 10-minute walk from a relative's house (OR 1.69, girls only).

Conclusions

Comprehensive multi-level interventions that reduce screen-time, encourage active travel to/from school and foster a physically active classroom culture might encourage more physical activity among children.

Physical activity levels and energy expenditure of 9-year-old – 12-year-old overweight and obese children

The high occurrence of overweight and obesity amongst children is a disturbing health problem worldwide. Possible causes of increasing childhood obesity are inactivity and energy imbalances. The aim of this study was to analyse the total energy expenditure (TEE)and physical activity levels in 9-year-old – 12-year-old overweight and obese children during a weekday and a weekend day, as well as during a weekday morning and afternoon. Twenty-four 9-year-old – 12-year-old children (seven boys and 17 girls), of whom nine were overweight and 15 were obese, were selected from seven public primary schools for this study. Body mass index (BMI) cut-off points were used to distinguish between overweight and obese. Each participant wore an ACTICAL™ monitor to determine their physical activity levels and TEE. It was found that the TEE of the children did not differ between a week day and a weekend day, although the TEE of the week day afternoon differed significantly from that of the weekday morning. Unlike the overweight children, none of the obese children met the requirements of 60 minutes of moderate-intensity physical activity per day. Strategies should be found to increase the activity levels of overweight and, especially, obese children, specifically during the mornings and over weekends.OpsommingDie hoë voorkoms van oorgewig en obesiteit onder kinders is wêreldwyd ’n kommerwekkende gesondheidsprobleem. Fisieke onaktiwiteit en energiewanbalanse word as moontlike oorsake van die probleem beskou. Die doel van hierdie studie was om die totale energieverbruik (TEV) en fisieke-aktiwiteitsvlakke van 9-jarige – 12-jarige oorgewig- en obese kinders tydens ‘n totale weeksdag en naweekdag te ontleed, asook tydens die oggend en middag van ‘n weeksdag. Vier-en-twintig 9-jarige – 12-jarige kinders (sewe seuns en 17 dogters), waarvan nege oorgewig en 15 obees was, is uit sewe publieke laerskole vir die studie gekies. Afsnypunte volgens die liggaamsmassa-indeks (LMI) is gebruik om tussen oorgewig en obees te onderskei. Elke deelnemer het ‘n ACTICAL™ monitor gedra om hul fisieke-aktiwiteitsvlakke en TEV te bepaal. Die studie het getoon dat die TEV van die kinders op ’n weeksdag en naweekdag nie verskil het nie, alhoewel TEV tydens die middag van die weeksdag betekenisvol verskil het van die oggend s’n. Anders as die oorgewig kinders, het geen van die obese kinders aan die voorgestelde riglyn van 60 minute se matig intensiewe fisieke aktiwiteit per dag voldoen nie. Strategieë moet gevind word om die vlakke van aktiwiteit van oorgewig en veral obese kinders te verhoog, spesifiek gedurende die oggende en oor naweke.

An investigation of patterns of children's sedentary and vigorous physical activity throughout the week

BACKGROUND

Participation in higher intensity activity (i.e. vigorous physical activity [VPA]) appears more consistently associated with lower adiposity, unfortunately little is known about the nature and patterns of VPA participation in children.

OBJECTIVE

To examine the volume and patterns of vigorous and sedentary activity during different segments of the week (weekend, school-based and out-of-school). We also investigated differences by sex, socioeconomic status (SES) and weight status.

DESIGN

A cross-sectional study including 1568 UK children aged 9-10 years.

OUTCOME MEASURES

Sedentary activity (mins), total activity (counts/min) and VPA (mins) were measured by accelerometry. Using a series of 2 level mixed effects linear regression models we tested differences across the segmented week (school time [0900-1500] vs. out-of-school time [0700-0900 & 1500-2100]; and weekday vs. weekend); all models were adjusted for sex, weight status (gender- and age-specific body mass index [BMI] cut points), SES, age and accelerometer registered wear time.

RESULTS

Boys and girls accumulated higher VPA out-of-school compared to during school (boys mean ± SD 16.9 ± 9.6 vs 12.6 ± 5.8; girls, 13.1 ± 7.7 vs 8.2 ± 4.0, both p < 0.001); but there were no differences for weekday v weekend VPA (p > 0.05). Less time was spent sedentary on weekdays compared to weekends (p < 0.001). Although boys were more physically active and girls accumulated more sedentary time, the overall pattern in which their physical activity intensity varied across the various day segments was similar when stratified by weight status and SES; and large volumes of sedentary time were observed each hour across the day.

CONCLUSIONS

The promotion of VPA during the weekend may hold the greatest promise for increasing VPA. Interventions aimed at increasing physical activity in 9-10 year old children should aim to target all children independent of sex, SES or weight status.

Applying generalizability theory to estimate habitual activity levels

PURPOSE

Relative and absolute decisions in physical activity research are commonly based on a single assessment period that may not represent habitual activity behavior. This study used the generalizability theory to 1) quantify multiple sources of measurement error and 2) estimate the number of days and seasons needed to characterize long-term levels of activity.

METHODS

Between 2005 and 2006, youth participating in an intervention program were asked to wear a pedometer across seven consecutive days during three separate months (September, January, and May). Total variance in activity was partitioned and quantified according to differences among participants, inconsistency across days, relative differences among seasons, and the interactions among variables. Two coefficients (generalizability and phi) were calculated from multiple decision studies using a random and mixed design to determine the study protocol needed to achieve a reliability of 0.80 for relative and absolute decisions, respectively. Data were analyzed in 2009.

RESULTS

Complete data were available for 42 boys and 38 girls. Residual variance accounted for the largest source of measurement error (55.64%), whereas smaller amounts were attributed to the participant (18.74%), season (6.59%), and day (2.67%) terms. Using a random design, both coefficients failed to reach an acceptable level of reliability using a single season. In contrast, using a mixed design, an acceptable level of reliability could be reached using 7-8 d from a single, fixed season.

CONCLUSIONS

This study demonstrates the potential for using the generalizability theory to make decisions regarding the rank order of activity among individuals (relative decision) and compliance rates for physical activity recommendations (absolute decision).

Physical activity and dietary intake of children aged 9-11 years and the influence of peers on these behaviours: a 1-year follow-up

BACKGROUND

This study investigated physical activity and dietary intake of children aged 9-11 years, and the influence of peers on these behaviours over a 2-year period.

METHODS

A total of 106 (64 girls; 42 boys) children were investigated annually, over 2 years. Measures included physical activity (sealed pedometer), self-report measures of dietary intake and physical activity, and a peer influence questionnaire. Anthropometric measures of height and weight were also obtained.

RESULTS

The findings reveal insufficient energy intakes, physical activity levels and fruit and vegetable consumption but high intakes of saturated fat and sodium, over time, in both boys and girls. Both male calcium and female iron intakes were also of concern. Throughout the survey, peers were found to influence physical activity behaviour but not dietary intake.

CONCLUSIONS

The fact that youth consistently failed to meet established nutrition and physical activity recommendations highlights the importance of promoting physical activity and healthy eating to children younger than 9 years of age. The finding that peers significantly influence physical activity behaviour over time should be considered when designing new physical activity interventions aimed at young people.

Pedometer-assessed physical activity of Singaporean youths

OBJECTIVE

The aim of the study was to investigate the pedometer-assessed physical activity of Singaporean youths using an objective measurement of physical activity.

METHODS AND RESULTS

Pedometer step count was monitored over the entire week in 877 participants aged 9-18 years in three schooling cohorts [primary (age, 9-12 years; n=150 males; 156 females), secondary (age, 13-16 years; n=137 males; 138 females) and junior college (age, 17-18 years; n=140 males; 156 females)] in Singapore during July to September 2009. Analyses identified significant main effects for step count taken outside of school compared to within school (mean (SD): 5568 (4796) vs. 3881 (3149), p<0.05). However, no significant difference was found for steps accumulated within or outside school in boys and girls across the schooling levels (steps x sex x level interaction, p>0.05). Step counts were not significantly different between weekdays or weekends (9719 (6063) vs. 9483 (8056), p>0.05), across schooling levels and between male and female participants (sex x level and steps x level x sex interactions, all p>0.05).

CONCLUSION

Step count decline is drastic for male adolescents after primary school but remains low across the schooling levels for female participants. Aggregated daily step count fell short by up to 35% of the 16,000 and 13,000 steps recommended respectively for male and female youths.

Day-dependent step-count patterns and their persistence over 3 years in 8-10-year-old children: the LOOK project

BACKGROUND

Physical activity in children is known to be generally lower at weekends but whether systematic day-to-day differences exist throughout the week is unclear.

AIM

To determine if weekly patterns of pedometer-assessed physical activity (PPA) exist in elementary school-aged Australian boys and girls and whether they persist over 3 years.

SUBJECTS AND METHODS

Seven-day pedometer measurements were recorded from 389 boys and 387 girls of initial age 8.0 (SD 0.3) in three successive years during spring. General linear mixed modelling was used to investigate patterns and the persistence of PPA.

RESULTS

A pattern did emerge, significant differences in PPA occurring between certain days of the week (p<0.001). This pattern was similar in each year, PPA increasing from Monday through to Friday, decreasing on Saturday and again on Sunday. PPA was greater in boys (p<0.001), but less so on weekends. Significant day-to-day and year-to-year intra-class correlations of PPA (0.14 and 0.29, respectively, both p<0.001)) within individuals provided evidence of tracking on a daily basis, and to a lesser extent yearly.

CONCLUSIONS

A well-defined week-long pattern of steps/day emerged in these 8-10-year-old children, the pattern being similar in three consecutive years.

Pedometer-measured physical activity patterns of youth: a 13-country review

CONTEXT

Insufficient physical activity among young people aged 5-18 years is a global public health issue, with considerable disparities among countries. A systematic review was conducted to identify studies reporting pedometer daily steps (steps x day(-1)) in order to compile comparative, global cross-sectional data on youth physical activity patterns.

EVIDENCE ACQUISITION

Articles were included if they were in English, published by April 2009, and reported steps x day(-1) for boys and girls, separately, and reported steps x day(-1) for age groupings of no more than 4 years (e.g., 5-8 years) or combined no more than three grade levels (e.g., third- to fifth-graders). Studies could have been intervention-based but had to have reported baseline steps x day(-1), which would reflect unadulterated physical activity steps x day(-1) estimates. Inverse variance weighted estimates (steps x day(-1w)) were calculated for each country, and random effects models were estimated. Analyses were conducted in May and June 2009.

EVIDENCE SYNTHESIS

Forty-three studies, representing young people in 13 countries (N=14,200), were included. The majority of studies were from the U.S. (17/43). Overall, there was considerable variation within and among countries in steps x day(-1w). Boys and girls from European and Western Pacific regions had significantly more steps x day(-1w) than young people from the U.S. and Canada. Significantly lower steps x day(-1w) estimates for girls were observed for studies that combined measured steps x day(-1) for weekdays and weekend days, in comparison to weekdays only.

CONCLUSIONS

Limited sample sizes and non-population-based data preclude definitive statements regarding projected steps x day(-1) within countries. Nevertheless, these findings provide preliminary information for policymakers and researchers on the extent of the disparities among countries in the physical activity patterns of young people.

Validation of a maternal questionnaire on correlates of physical activity in preschool children

Background

Valid measures of physical activity correlates in preschool children are lacking. This study aimed to assess the validity, factor structure and internal consistency of a maternal questionnaire on potential correlates of four-year-old children's physical activity.

Methods

The questionnaire was designed to measure the following constructs: child personal factors; parental support and self-efficacy for providing support; parental rules and restrictions; maternal attitudes and perceptions; maternal behaviour; barriers to physical activity; and the home and local environments. Two separate studies were conducted. Study I included 24 mothers of four-year-old children who completed the questionnaire then participated in a telephone interview covering similar items to the questionnaire. To assess validity, the agreement between interview and questionnaire responses was assessed using Cohen's kappa and percentage agreement. Study II involved 398 mothers of four-year-old children participating in the Southampton Women's Survey. In this study, principal components analysis was used to explore the factor structure of the questionnaire to aid future analyses with these data. The internal consistency of the factors identified was assessed using Cronbach's alpha.

Results

Kappa scores showed 30% of items to have moderate agreement or above, 23% to have fair agreement and 47% to have slight or poor agreement. However, 89% of items had fair agreement as assessed by percentage agreement (≥ 66%). Limited variation in responses to variables is likely to have contributed to some of the low kappa values. Six questions had a low kappa and low percentage agreement (defined as poor validity); these included questions from the child personal factors, maternal self-efficacy, rules and restrictions, and local environment domains. The principal components analysis identified eleven factors and found several variables to stand alone. Eight of the composite factors identified had acceptable internal consistency (α ≥ 0.60) and three fell just short of achieving this (0.60 > α > 0.50).

Conclusion

Overall, this maternal questionnaire had reasonable validity and internal consistency for assessing potential correlates of physical activity in young children. With minor revision, this could be a useful tool for future research in this area. This, in turn, will aid the development of interventions to promote physical activity in this age group.

Effects of peer influence on dietary intake and physical activity in schoolchildren

Objective

To investigate the dietary intake and physical activity of boys and girls aged 9–13 years, and the influence of peers on these behaviours.

Design

Cross-sectional study.

Setting

Nine primary and secondary schools in south-west London.

Subjects

A total of 315 children wore sealed pedometers, provided self-report measures of dietary intake and answered a questionnaire relating to peer influence. Anthropometric measures of height and weight were also obtained.

Results

Obese children had the lowest reported energy intakes and the lowest step counts per day. Boys took significantly more steps per day than girls, however girls were closer to achieving their recommended cut-offs for physical activity. Girls had lower energy intakes per day and lower BMI Z-scores than boys, however both genders, across all age groups, had higher than recommended intakes of saturated fat. There were significant associations between peer influence and physical activity levels but not between peer influence and dietary intake.

Conclusions

Low energy intake and physical activity levels but high saturated fat intakes among boys and girls across all age groups highlight the importance of promoting both physical activity and healthy food choices. The finding that peers have a significant effect on physical activity levels but not on dietary intake offers an important approach for the design of health promotion interventions and obesity prevention programmes. Such designs may be particularly beneficial for obese youth, since the low physical activity levels found could be a major contributing factor to the maintenance of the condition.

Expected values for pedometer-determined physical activity in youth

This review assembles pedometry literature focused on youth, with particular attention to expected values for habitual, school day, physical education class, recess, lunch break, out-of-school, weekend, and vacation activity. From 31 studies published since 1999, we constructed a youth habitual activity step-curve that indicates: (a) from ages 6 to 18 years, boys typically take more steps per day than girls; (b) for both sexes the youngest age groups appear to take fewer steps per day than those immediately older; and (c) from a young age, boys decline more in steps per day to become more consistent with girls at older ages. Additional studies revealed that boys take approximately 42-49% of daily steps during the school day; girls take 41-47%. Steps taken during physical education class contribute to total steps per day by 8.7-23.7% in boys and 11.4-17.2% in girls. Recess represents 8-11% and lunch break represents 15-16% of total steps per day. After-school activity contributes approximately 47-56% of total steps per day for boys and 47-59% for girls. Weekdays range from approximately 12,000 to 16,000 steps per day in boys and 10,000 to 14,000 steps perday in girls. The corresponding values for weekend days are 12,000-13,000 steps per day in boys and 10,000-12,000 steps per day in girls.

Exercise for preventing childhood obesity

Childhood obesity is a key public health issue in the United States and around the globe in developed and developing countries. Obese children are at increased risk of acute medical illnesses and chronic diseases-in particular, osteoarthritis, diabetes mellitus, and cardiovascular disease, which can lead to poor quality of life; increased personal and financial burden to individuals, families, and society; and shortened lifespan. Physical inactivity and sedentary lifestyle are associated with being overweight in children and adults. Thus it is imperative to consider exercise and physical activity as a means to prevent and combat the childhood obesity epidemic. Familiarity with definitions of weight status in children and health outcomes like metabolic syndrome is crucial in understanding the literature on childhood obesity. Exercise and physical activity play a role in weight from the prenatal through adolescent time frame. A child's family and community impact access to adequate physical activity, and further study of these upstream issues is warranted. Recommended levels of physical activity for childhood obesity prevention are being developed.