Activity levels and body mass index of children in the United States, Sweden, and Australia

The Level and Factors Differentiating the Physical Fitness of Adolescents Passively and Actively Resting in South-Eastern Poland-A Pilot Study

Physical activity (PA) is defined as any bodily movement produced by skeletal muscles that requires energy expenditure. Due to civilization's development, we can observe a global decline in physical activity which negatively affects the state of physical and mental health. The physical activity of children and adolescents is a counterpart to their physical fitness. There is also more frequent spending of free time in a passive way rather than actively. The aim of the study was to determine whether there are differences in the physical fitness of young people who rest passively in relation to those who rest actively. In addition, it was checked whether factors, such as age, weight, body height and BMI differentiate the level of fitness in adolescents. Study group: 25 boys and 25 girls declaring active leisure activities. Control group: 25 boys and 25 girls declaring passive leisure activities. Age of the respondents ranged from 11 to 15 years (Me = 13; SD = 1.23). The research used: the author's questionnaire and the Index of Physical Fitness of K. Zuchora. The results were statistically developed. The youth who spend their free time actively were characterised by a higher level of physical fitness than their peers who choose passive recreation. The students with a higher BMI obtained worse results than the children with a lower body mass index. In both groups, slightly better results were obtained by girls. A significant relationship between age and results has been observed in the control group-the results increased with increasing age. The level of physical fitness is higher in active forms of recreation than in passive rest. Physical fitness tends to increase with age but decreases with increasing BMI. Girls are characterised by a higher level of physical fitness than boys.

Physical Activity and Related Factors in Pre-Adolescent Southern African Children of Diverse Population Groups

Tailored obesity management includes understanding physical activity (PA) and its context, ideally in childhood before the onset of health risk. This cross-sectional study determined, by sex and population, the PA of Southern African pre-adolescent urban primary school children. PA was measured objectively (step count: pedometer) and subjectively (Physical Activity Questionnaire for Older Children [PAQ-C]), taking confounders (phenotype, school-built environment, and socio-economic environment) into account. Body composition was measured with multifrequency bioelectrical impedance analysis (Seca mBCA). PA was adjusted for phenotypic confounders (body size and composition) using multivariate regression. Sex and population differences in PA were determined with two-way ANOVA. Ninety-four healthy pre-adolescents (60% girls, 52% black) with a similar socio-economic status and access to PA participated. Amidst phenotypic differences, average steps/day in girls (10,212) was lower than in boys (11,433) (p = 0.029), and lower in black (9280) than in white (12,258) (p < 0.001) participants. PAQ-C scores (5-point rating) were lower for girls (2.63) than boys (2.92) (p < 0.001) but higher for black (2.89) than white (2.58) (p < 0.001) participants. Objective and subjective measurements were, however, not significantly (r = −0.02; p = 0.876) related and PAQ-C failed to identify reactive changes in the step count. Objectively measured PA of black participants and of girls was consistently lower than for white participants and boys. Target-group specific interventions should therefore be considered.

Time Trends in Physical Activity Using Wearable Devices: A Systematic Review and Meta-analysis of Studies from 1995 to 2017

INTRODUCTION

Conflicting evidence exists on whether physical activity (PA) levels of humans have changed over the last quarter-century. The main objective of this study was to determine if there is evidence of time trends in PA, from cross-sectional studies that assessed PA at different time points using wearable devices (e.g., pedometers and accelerometers). A secondary objective was to quantify the rate of change in PA.

METHODS

A systematic literature review was conducted of English-language studies indexed in PubMed, SPORTDiscus, and Web of Science (1960-2020) using search terms (time OR temporal OR secular) AND trends AND (steps per day OR pedometer OR accelerometer OR MVPA). Subsequently, a meta-analytic approach was used to aggregate data from multiple studies and to examine specific factors (i.e., sex, age-group, sex and age-group, and PA metric).

RESULTS

Based on 16 peer-reviewed scientific studies conducted between 1995 and 2017, levels of ambulatory PA are trending downward in developed countries. Significant declines were seen in both males and females (P < 0.001) as well as in children (P = 0.020), adolescents (P < 0.001), and adults (P = 0.004). The average study duration was 9.4 yr (accelerometer studies, 5.3 yr; pedometer studies, 10.8 yr). For studies that assessed steps, the average change in PA was -1118 steps per day over the course of the study (P < 0.001), and adolescents had the greatest change in PA at -2278 steps per day (P < 0.001). Adolescents also had the steepest rate of change over time, expressed in steps per day per decade.

CONCLUSIONS

Evidence from studies conducted in eight developed nations over a 22-yr period indicates that PA levels have declined overall, especially in adolescents. This study emphasizes the need for continued research tracking time trends in PA using wearable devices.

The Associations between Physical Fitness, Complex vs Simple Movement, and Academic Achievement in a Cohort of Fourth Graders

This study analyzed the correlation between elementary school students’ body composition, physical activity, physical fitness, movement ability, and academic achievement. Movements ranged from simple actions to complex movements requiring executive functioning. In total, 110 fourth graders (60 boys, 50 girls) participated in this experiment. Body composition (BMI, % of body fat), physical activity (pedometer), physical fitness (muscular strength, endurance, power, flexibility, and VO₂max), and complex movement abilities (Illinois Agility test, soda pop hand test, and soda pop foot test) were measured. Regression modeling of body composition and fitness/activity variables was able to account for 30.5% of the variation of total academic scores in females, but only 4.3% in males. No individual tests were reliably correlated with multiple academic outcomes in males. However, hand and foot soda pop times, as well as Illinois Agility scores, were repeatedly correlated with academic outcomes in females, each correlating with 4 of the 6 academic scores. Body composition and physical activity level did not correlate with academic achievement, and simple physical fitness showed a low correlation with academic achievement in both boys and girls. On the other hand, complex, cognitively demanding movements such as the Illinois Agility, soda pop hand, and soda pop foot tests had consistent correlations with academic achievement in girls, but not in boys.

Pedometer-determined physical activity among primary schoolchildren in Kuala Lumpur

Objective:

The aim of this study was to objectively measure physical activity and its association with sociodemographic factors among Malaysian primary school-age children.

Methods:

A total of 111 primary school children in Kuala Lumpur were selected through random sampling. Activity pattern was determined using pedometers and differences by sex, ethnicity and body mass index categories were analysed. The relationship between pedometer-determined physical activity and sociodemographic factors were also studied.

Results:

Overall, boys attained significantly higher daily step counts than girls (9573 ± 4145 vs 7313 ± 2697). Significant difference in daily step counts between boys and girls were observed during weekdays ( p<0.01), weekends ( p<0.05) and total mean step counts ( p<0.01). Malay ethnicity showed higher daily step counts during weekdays than weekends ( p<0.05). Compared with boys, girls had higher odds (OR=5.58; 95% CI 1.12, 27.77) of not meeting the recommended daily step counts. Those who had low physical activity levels had higher odds (OR=15.75; 95% CI 1.78, 139.33) of not meeting recommended daily step counts than children who had moderate physical activity level.

Conclusion:

Boys were significantly more active than girls and physical activity was greater during weekdays than on weekends. The primary schoolchildren in Kuala Lumpur were sedentary, with minimum physical activity being observed. Differences in sexes and physical activity levels influenced pedometer step counts in children.

Associations Between Pedometer-Determined Physical Activity and Adiposity in Children and Adolescents: Systematic Review

OBJECTIVE

The present review sought to examine the evidence on the associations between pedometer-determined physical activity and adiposity.

DESIGN

Of 304 potentially eligible articles, 36 were included. A search for observational studies was carried out using Cochrane Library (CENTRAL), the OVID (MEDLINE, Embase, and PsycINFO), EBSCOhost (Sportdiscus), and PEDro database from their commenced to July 2015. Of 304 potentially eligible articles, 36 were included.

RESULTS

Most studies (30/36; 83%) were cross sectional and all used proxies for adiposity, such as body mass index (BMI) or BMI z-score as the outcome measure. Few studies (2/36; 6%) focused on preschool children. There was consistent evidence of negative associations between walking and adiposity; significant negative associations were observed in 72% (26/36) of studies overall.

CONCLUSIONS

The present review supports the hypothesis that higher levels of walking are protective against child and adolescent obesity. However, prospective longitudinal studies are warranted; there is a need for more research on younger children and for more "dose-response" evidence.

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.

The Relationship Between Parental and Child Physical Activity in a Rural Community

This study examined the relationship between parental and child physical activity (PA) in a rural community. Forty-one children and at least 1 parent wore pedometers to measure step count over the course of 4 days. Parents also completed a PA survey assessing parental support for PA, parental enjoyment for PA, perceived importance of PA, and their own PA levels. Parental PA level and mothers' support for PA were moderately associated with their child's PA levels. Thus, future PA promotion efforts could focus on encouraging parents, primarily mothers, to be more active to help improve their child's PA levels.

Pedometer-determined physical activity among youth in the Tokyo Metropolitan area: a cross-sectional study

Background

Providing large-scale descriptive data of objectively measured physical activity in youth is informative for practitioners, epidemiologists, and researchers. The purpose of this study was to present the pedometer-determined physical activity among Japanese youth using the Tokyo Metropolitan Survey of Physical Fitness, Physical Activity and Lifestyle 2011.

Methods

This study used a school-based survey. The Tokyo Metropolitan Board of Education originally collected pedometer-determined steps per day in the fall of 2011. Data were collected from 15,471 youth aged 6 to 18 years living in Tokyo. Participants were asked to wear pedometers for 14 consecutive days, and daily steps logged in the final 7 days were selected for this analysis.

Results

At the primary and junior high school levels, boys (12,483 and 9476, respectively) had a significantly higher mean number of steps per day than did girls (10,053 and 8408, respectively). There was no significant difference in the mean number of steps per day between the sexes at the high school level. Mean steps per day decreased consistently with age and grade level; the lowest overall steps per day was observed in the last year of junior high school, although there was a slight increase in the subsequent year, the first year of high school.

Conclusions

This study demonstrates a trend toward reduced physical activity with age in Japanese youth and a substantial difference in the number of steps per day between boys and girls in Tokyo. The age-related reduction in steps per day was greater in boys because they attained a higher peak value prior to this reduction, and sex-related differences in the step count disappeared in high school students.

Secular trends in the prevalence of childhood overweight and obesity across Australian states: A meta-analysis

OBJECTIVE

To describe secular trends in the prevalence of overweight and obesity in Australian children in each state and territory.

DESIGN

Systematic search and numerical meta-analysis.

METHODS

A systematic search was conducted to identify all sources that objectively measured the height and weight of Australian children (aged 2-18 years) and had a sample size of at least 300. Raw and summary data were requested from authors and divided into age×sex×state×yearly slices to derive estimates of the prevalence of overweight and obesity. Following a double arcsine transformation to facilitate meta-analysis, all estimates were standardised for age, stratified by sex and analysed using sample-weighted non-linear regressions.

RESULTS

The systematic search identified 73 eligible sources (47 raw and 26 summary datasets), with 72.8% of data sourced from Victoria and South Australia. Prevalence trends varied from state to state, with three states or territories showing a marked plateau, two showing a decline in the more recent years and three showing continued linear increases. Tasmania and Northern Territory generally had the highest prevalence (30.2% and 24.3% overweight and obesity respectively), and the Australian Capital Territory had the lowest (12.4% overweight and obesity).

CONCLUSIONS

Prevalence, as well as prevalence trends, varied amongst Australian states and territories. At a national level, the prevalence trend has nearly plateaued for the past 15 years. However, upward prevalence trends appear to be persisting in Western Australia, South Australia and Tasmania. Findings highlight the need for ongoing efforts to address the issue of childhood obesity.

Correlation of Body Mass Index and Physical Activity Among 7- to 11-Year Children at Zahedan, Iran

Background:

Childhood obesity is currently one of the major concerns in pediatric field. In recent literature, correlation of obesity with some behavioral factors such as physical activity (PA) received attention.

Objective:

The purpose of this study was to determine the relationship between body mass index (BMI) and PA.

Materials and Methods:

This cross-sectional study was carried out in 2012 on 548 randomly selected 7- to 11-year schoolchildren from Zahedan, Iran. The underweight, normal weight, overweight, and obesity status were all based on BMI percentiles for age and sex. Moderate to vigorous PA during the previous 7 days was assessed by a modified version of the Physical Activity Questionnaire for Children.

Results:

The prevalence of underweight, normal weight, overweight, and obesity among the participants was 18.3%, 47.9%, 11.8%, and 22.1%, respectively. Overweight and obesity were significantly higher among girls than boys. Mean PA score in participants was 2.4 ± 0.5. The results showed the PA score was significantly higher among boys than girls. The PA score had a significant association with BMI ( P = .018), and it was greater in normal participants than in obese participants.

Conclusion:

On the basis of observed data and due to the impact of PA on BMI as an indicator of nutritional status and health, teaching children to have better nutrition and lifestyle changes is very important. Therefore, more studies should focus on childhood obesity prevention programs to prevent nonoverweight children from becoming overweight or obese in the future.

Physical Activity of Young Children

Occupational therapists concerned with the long-term health and welfare of children need to be aware of the decline in physical activity of children in most Western societies. The current study examined the extent of physical activity in the lives of 50 Australian children with a mean age of 7.74 years through questionnaires completed by the children's parents and pedometer (step) data collected from the children during 4 days. The current data show that higher self-perception of physical competence, child's levels of physical skill, and low parental perception of peer teasing were the best predictors of physical activity. Higher family socioeconomic status was found to be a significant predictor of more steps being taken on weekends, and partner's (usually a father's) level of exercise was an important predictor of the number of weekend steps. Children who were perceived to experience more peer teasing completed fewer steps on the weekend. The findings from this study indicate that children's physical activity levels may depend on the availability of family resources, and that children in their early school years may already experience negative effects from teasing that, combined with reduced self-confidence, may lay the foundation for their withdrawing from physical activity as they get older.

Physical Activity, Blood Glucose and C-Peptide in Healthy School-Children, a Longitudinal Study

Aim

To further elucidate the relationship between physical activity and several risk factors for development of diabetes (glucose, C-peptide and obesity) over time.

Methods

A prospective longitudinal study where physical activity was measured on 199 children from Kalmar and Linköping at age 8, and the same 107 children from Linköping again at age 12. Anthropometric data was collected and blood was analyzed for C-peptide and f-glucose. The children in the study were representative for the general Swedish child population, and on an average lean.

Results

High physical activity was related to lower C-peptide at age 8 and 12. This correlation was especially pronounced in boys, who also were more physically active than girls at both time points. The association seen at 8 years of age was similar at age 12 in most children. Children with higher BMI Z-Score had a higher fasting C-peptide (age 12) but linear regression showed that children with more steps per day were less likely to have a higher fasting C-peptide irrespective of BMI. Longitudinal follow-up showed that a decrease in physical activity increased insulin resistance and β-cell load.

Conclusions

Already in young children, physical activity improves insulin sensitivity and decreases the need of C-peptide over time. This seems to become even more pronounced with increasing age when children are followed longitudinally. Low physical activity increases the load on insulin producing β-cells, might increase the risk for both type 1- and 2 diabetes.

Social capital and physical activity among Croatian high school students

OBJECTIVE

To examine factors associated with regular physical activity in Croatian adolescents.

STUDY DESIGN

A cross-sectional survey among high school students was carried out in the 2013/14 school year.

METHOD

A survey was conducted among 33 high schools in Zagreb City, Croatia. Participants were students aged 17-18 years. The dependent variables were regular moderate to vigorous physical activity (MVPA) and overall physical activity measured by the short version of International Physical Activity Questionnaire and defined as 60 min or more of daily physical activity. The independent variables included family, neighborhood, and high school social capital. Other study covariates included: socio-economic status, self-rated health, psychological distress and nutritional status. The associations between physical activity and social capital variables were assessed separately for boys and girls through multiple logistic regression and inverse probability weighting in order to correct for missing data bias.

RESULTS

A total of 1689 boys and 1739 girls responded to the survey. A higher percentage of boys reported performing regular vigorous and moderate physical activity (59.4%) and overall physical activity (83.4%), comparing with the girls (35.4% and 70%, respectively). For boys, high family social capital and high informal social control were associated with increased odds of regular MVPA (1.49, 95%CI: 1.18 - 1.90 and 1.26, 95%CI: 1.02 - 1.56, respectively), compared to those with low social capital. For girls, high informal social control was associated with regular overall physical activity (OR 1.38, 95% CI: 1.09 - 1.76).

CONCLUSION

High social capital is associated with regular MVPA in boys and regular overall activity in girls. Intervention and policies that leverage community social capital might serve as an avenue for promotion of physical activity in youth.

Neighborhood environment and physical activity among young children: a cross-sectional study from Sweden

AIMS

The aims of this study were to investigate the association between the neighbourhood environment and physical activity among young children in a Scandinavian setting, and to assess the influences of seasonal variations, age, sex and parental education.

METHODS

Physical activity was assessed with an accelerometer and neighbourhood resources were estimated using geographic information systems for 205 Swedish children aged 4-11 years. Neighbourhood resources were generated as the sum of three neighbourhood attributes: (a) foot and bike paths, (b) non-restricted destinations and (c) recreational area, all within 300 m of each child's home. Physical activity was assessed as: (a) total volume of physical activity (i.e. counts per minute), (b) sedentary time and (c) moderate to vigorous physical activity (MVPA). The association between neighbourhood resources and physical activity was analysed using mixed linear models weighted by measurement time and adjusted for sex, age, season of activity measurement, type of housing and parental education.

RESULTS

Children were more physically active in areas with intermediate access to neighbourhood resources for physical activity compared to areas with worst access, while the difference between intermediate and best neighbourhood resource areas was less clear. The association between physical activity and neighbourhood resources was weaker than with seasonal variations but compatible in magnitude with sex, age, type of housing and parental education. Among specific neighbourhood attributes, the amount of foot and bike paths was associated with less sedentary time and more MVPA.

CONCLUSIONS

This study provides some, not entirely consistent, evidence overall for an association between the neighbourhood environment and physical activity among young children in Scandinavia.

Self-efficacy, physical activity, and aerobic fitness in middle school children: examination of a pedometer intervention program

Physical activity in children has been associated with a number of health benefits. Unfortunately, physical inactivity continues to increase. The purpose of this study was to examine the relationships among self-efficacy levels, physical activity, aerobic fitness, and body composition (relative body mass index [RBMI]) and to determine whether a school-based pedometer intervention program would improve those variables. The sample consisted of 116 rural 11- to 13-year-old students. Weakly positive correlations between self-efficacy, physical activity, and aerobic fitness and weakly correlated inverse relationships between self-efficacy, physical activity, aerobic fitness and RBMI were found. There was no statistical significance between the intervention and control group when analyzing outcome variables. These findings suggest that those with optimal RBMI levels have higher self-efficacy, physical activity and aerobic fitness levels. Although not statistically significant, the intervention group had greater improvements in mean self-efficacy scores, aerobic fitness levels, and RBMI.

Walking activity of children with cerebral palsy and children developing typically: a comparison between the Netherlands and the United States

PURPOSE

To compare walking activity of children with and without cerebral palsy (CP) between the Netherlands and the United States.

METHODS

A cross-sectional analysis on walking activity data from an international retrospective comparison study including a convenience sample of 134 walking children aged 7-12 years with spastic CP, classified as Gross Motor Function Classification System (GMFCS) level I (N = 64), II (N = 49) or III (N = 21), and 223 typically developing children (TDC) from the Netherlands and the United States. Walking activity was assessed during a one-week period using a StepWatch™ activity monitor. Outcomes were the daily number of strides, daily time being inactive and spent at low (0-15 strides/min), moderate (16-30 strides/min) and high stride rate (31-60 strides/min). Walking activity was compared between countries using multiple linear regression analyses.

RESULTS

Walking activity of TDC was not significantly different between countries. Compared to their American counterparts, Dutch children in GMFCS level I and II showed less walking activity (p < 0.05), whereas Dutch children in GMFCS level III showed more walking activity (p < 0.05).

CONCLUSION

The absence of differences in walking activity between Dutch and American TDC, and the presence of differences in walking activity between Dutch and American children with CP suggest that between-country differences affect walking activity differently in children with CP.

IMPLICATIONS FOR REHABILITATION

Physical activity of children with CP should be promoted in both the United States and the Netherlands. The between-country differences in walking activity illustrate that apart from the severity of the CP walking activity seems to be influenced by environmental aspects. In the promotion of physical activity, practitioners should pay attention to environmental barriers that families may experience for increasing physical activity.

Parental obesity as a predictor of childhood overweight/obesity in Australian migrant children

SUMMARY

Obesity levels are increasing disproportionately in immigrant children worldwide. We investigated predictors of immigrant children's obesity status in a well-documented 3-year follow-up study of children at 9 years (n = 1232) and 12 years (n = 628) of age living in inner city areas of Sydney (Australia). The major immigrant groups in this sample were from Europe, the Middle East and SE Asia. Having an obese parent and having either parent or child not being born in Australia and not playing organised sport were predictors of childhood obesity. If either parent was obese compared to non-obese, then the odds ratio for a 9-year-old child of being obese compared to normal weight was 4.9 (95% CI: 3.0-8.0); for 12-year olds the odds ratio was 8.0 (95% CI: 3.6-18). For the survey of 9-years old, a parent born outside Australia or if the child himself was born outside Australia was associated with an almost twofold chance of being obese (OR = 1.8, 95% CI: 1.1-3.0), and not participating in organised sports was significantly associated with childhood obesity. Nine-year olds who did not participate in organised sports outside of school hours were almost twice as likely to be obese (OR = 1.9, 95% CI: 1.2-2.9). When stratified by ethnicity, participation in sports was not related to lower obesity status in children of SE Asian origin. One reason for this could be because SE Asian had very limited participation in sports compared to their counterparts. Accordingly, we believe that health promotion messages to avoid obesity need to be targeted ethnic-specifically.:

Sizing the association between lifestyle behaviours and fatness in a large, heterogeneous sample of youth of multiple ethnicities from 4 countries

Background

The magnitude of the relationship between lifestyle risk factors for obesity and adiposity is not clear. The aim of this study was to clarify this in order to determine the level of importance of lifestyle factors in obesity aetiology.

Methods

A cross-sectional analysis was carried out on data on youth who were not trying to change weight (n = 5714), aged 12 to 22 years and from 8 ethnic groups living in New Zealand, Australia, Fiji and Tonga. Demographic and lifestyle data were measured by questionnaires. Fatness was measured by body mass index (BMI), BMI z-score and bioimpedance analysis, which was used to estimate percent body fat and total fat mass (TFM). Associations between lifestyle and body composition variables were examined using linear regression and forest plots.

Results

TV watching was positively related to fatness in a dose-dependent manner. Strong, dose-dependent associations were observed between fatness and soft drink consumption (positive relationship), breakfast consumption (inverse relationship) and after-school physical activity (inverse relationship). Breakfast consumption-fatness associations varied in size across ethnic groups. Lifestyle risk factors for obesity were associated with percentage differences in body composition variables that were greatest for TFM and smallest for BMI.

Conclusions

Lifestyle factors were most strongly related to TFM, which suggests that studies that use BMI alone to quantify fatness underestimate the full effect of lifestyle on adiposity. This study clarifies the size of lifestyle-fatness relationships observed in previous studies.

Effect of BMI on pedometers in early adolescents under free-living conditions

PURPOSE

Pedometers may provide valuable information regarding the ambulatory patterns of adolescents, but the effects of body mass index (BMI) on pedometer accuracy in this population are unknown.The purpose of this study was twofold: 1) to determine whether the New Lifestyles NL-2000 (NL) and the Digi-Walker SW-200 (DW) (New Lifestyles, Inc., Lees Summit, MO) yield similar step counts as compared with an ankle-mounted criterion, StepWatch 3, when worn by early adolescents in a free-living environment and 2) to study whether BMI percentile affects the accuracy of waist-mounted pedometers in adolescents.

METHODS

Seventy-four early adolescents (13.0 ± 1.1 yr) wore the devices during one weekday. The study population included 33 normal weight, 21 overweight, and 20 obese participants. Two-way repeated-measures ANOVA was used to determine whether the BMI and the device were related to the number of steps per day and percentage of actual steps.

RESULTS

The NL and DW recorded fewer steps than the StepWatch 3 in each BMI category (P < 0.05). In the obese group, the DW underestimated the steps more than the NL (P < 0.001). For the normal weight, overweight, and obese groups, the NL counted 89.1%, 89.1%, and 91.6% of the steps, respectively, whereas the DW counted 86.7%, 84.6%, and 72.7%, respectively.

CONCLUSION

Researchers must be cognizant of the limitations of waist-mounted pedometers and carefully choose a device that suits the needs of their investigations. Because of the inaccuracies of the DW when measuring steps in obese adolescents, careful consideration must be given before choosing this device for research and interventions. The NL is a better device for assessment of adolescents' steps than the DW, especially for those who are obese.

Feasibility of using pedometers to measure daily step counts in cystic fibrosis and an assessment of its responsiveness to changes in health state

BACKGROUND

Evaluation of physical activity is integral to the assessment of daily physical function and a potential objective outcome measure for clinical trials. We evaluated the feasibility of using pedometers to measure physical activity in adolescents and adults with cystic fibrosis (CF) and assessed the responsiveness of its measurement to changes in health state.

METHODS

Participants were recruited through two CF clinics in Seattle, WA. Subjects were instructed to use their pedometer for at least one ill and two well periods (each lasting 7 days). Step rate was calculated as steps per hour of use. Daily symptoms were also recorded using the CF Respiratory Symptom Diary (CFRSD). Generalized estimating equation linear regression was used to compare mean step rate between health states and by self-reported symptom category.

RESULTS

We enrolled 30 CF patients with a mean (±SD) age of 22 (±7) years and a mean forced expiratory volume in 1s (FEV(1)) of 57% (±25%) predicted. The mean period step rate increased from 397 (95% CI 324-497) steps/hour when ill to 534 (95% CI 413-654) steps/hour when well (p=0.015). Pedometer-recorded step rate also correlated with self-reported physical activity items on the CFRSD.

CONCLUSION

Step rate measured with a pedometer correlates significantly with changes in health status and self-reported activity, and could be used as an outcome measure in CF.

Daily steps among Finnish adults: variation by age, sex, and socioeconomic position

AIMS

The aim of this study was to provide descriptive population-based pedometer data from adults aged 30-45 years in Finland, and to compare daily step counts with evidence-based indices.

METHODS

The data was collected from 1853 participants in 7 consecutive days in winter 2007-08 in part of 27-year follow up of the Cardiovascular Risk in Young Finns study.

RESULTS

The participants took (mean±standard deviation) 7499 ± 2908 steps/day. Step counts included 1925 ± 2052 aerobic steps/day gathered in bouts of at least 10 min continuous ambulatory activity. Women had more total steps than men ((7824 ± 2925 vs. 7089 ± 2774; p < 0.001). Although participants had higher mean total steps on weekdays than on weekend days, they took more aerobic steps on weekend days than weekdays (p < 0.001). High-level non-manual work, and unemployment were associated with having fewer total steps, but high-level non-manual workers had more aerobic steps than other occupation groups. According to pedometer thresholds proposed by Tudor-Locke and Basset, 26% of men and 16% of women could be classified as inactive (<5000 steps/day) and 20% of women and 15% of men would be classified as active (>10,000 steps/day).

CONCLUSIONS

We conclude that about one-quarter of men and one-fifth of women are considered as inactive, based on the number of daily total steps. Our results suggest that total steps may provide a very different picture of activity from aerobic steps; important differences are evident by socioeconomic position and day of the week.

Effects of interactive video game cycling on overweight and obese adolescent health

The purpose of this study was to examine the efficacy of interactive video game stationary cycling (GameBike) in comparison with stationary cycling to music on adherence, energy expenditure measures, submaximal aerobic fitness, body composition, and cardiovascular disease risk markers in overweight and obese adolescents, using a randomized controlled trial design. Thirty overweight (with at least 1 metabolic complication) or obese adolescents aged 12-17 years were stratified by gender and randomized to video game or music condition, with 4 participants (2 per group) failing to complete the twice weekly 60 min sessions of the 10-week trial. The music group had a higher rate of attendance compared with the video game group (92% vs. 86%, p < 0.05). Time spent in minutes per session at vigorous intensity (80%-100% of predicted peak heart rate) (24.9 ± 20 min vs. 13.7 ± 12.8 min, p < 0.05) and average distance (km) pedaled per session (12.5 ± 2.8 km vs. 10.2 ± 2.2 km, p < 0.05) also favoured the music group. However, both interventions produced significant improvements in submaximal indicators of aerobic fitness as measured by a graded cycle ergometer protocol. Also, when collapsed, the exercise modalities reduced body fat percentage and total cholesterol. The present study indicates that cycling to music was just as effective as stationary cycling while playing video games at improving fitness, body composition, and cholesterol profiles in overweight and obese teens, and resulted in increased attendance, vigorous intensity of physical activity, and distance pedaled. Therefore, our data support the superiority of cycling to music and indicate investing in the more expensive GameBike may not be worth the cost.

Reference values on the 6-minute walk test for children living in the United States

PURPOSE

: The purpose of this study was to investigate reference values for the 6-minute walk test (6MWT) and the relationship between 6-minute walk distance (6MWD) and age, sex, and anthropometric variables in children who are healthy, aged 7 to 11 years and living in the United States.

METHODS

: The sample included 100 children, 57 female, 43 male, mean age 9.66 ± 1.08 years. Measures included height, weight, body mass index, leg length, and 6MWD.

RESULTS

: Mean 6MWD was 518.50 ± 73.56 m. Values were lower than those reported for children living in other countries with the exception of England. There were no significant associations between the 6MWD and other variables with the exception of body mass index in males.

CONCLUSION

: Our findings suggest 6MWT values for children living in other countries may not be directly applicable to children living in the United States.

The significant drop in physical activity among children on holidays in a small town in the Tohoku district

In Japan, there is a higher incidence of childhood obesity in the Tohoku district than in other areas. It is known that reduced physical activity is associated with increased body weight, but little is known about the physical activity patterns of children in this area. Accordingly, this study was designed to measure the physical activity of 145 children (73 boys and 72 girls) in Hashikami Town, Aomori Prefecture. Physical activity was assessed through a questionnaire as well as through two weeks of pedometer use. Boys spent more time engaging in physical activity than girls did, reporting 9.5 (0.6-22.0) versus 7.0 (1.2-21.5) hours per week [median (range)] (p=0.002). On school days, boys took an average of 13,586+/-4,386 (mean+/-SD) steps per day, while girls took 12,248+/-4,112; on holidays, boys took 9,531+/-4,557, while girls took 9,419+/-4,524. There was no significant sex-based difference in the number of steps per day (F=1.197, p=0.276), but both boys and girls significantly reduced the number of steps they took on holidays (F=116.537, p<0.001). In addition, 36 (24.8%) children reduced the number of steps they took by more than 50% on holidays compared to school days. In general, the participants engaged in the internationally recommended amounts of physical activity. Yet their reduced level of physical activity on holidays seems to be a matter for concern, as it is a possible cause of the higher incidence of childhood obesity in this area.

Pedometer step count and BMI of Irish primary school children aged 6-9 years

OBJECTIVE

(1) To assess step count and Body Mass Index in Irish children, (2) to examine variation in (i) weekday and weekend activity, (ii) during-school and after-school activity, and (3) to evaluate the utility of pedometer based PA recommendations for health in predicting Body Mass Index.

METHODS

Three hundred and one Irish primary school children aged 6-9 years wore a sealed pedometer for seven consecutive days in 2008, had their height and weight measured, and completed a short Physical Activity questionnaire.

RESULTS

The majority of children were classed as of normal weight, and met the age and sex specific pedometer recommendations for health. Children took significantly more steps at weekends than on weekdays, and after school than during school. A child being classed as normal or overweight/obese based on Body Mass Index did not predict the likelihood of them meeting the pedometer recommendations.

CONCLUSIONS

The majority of children were achieving sufficient steps/day for health but interventions to target those falling short should be considered. Further research examining the relationship between steps per day and Body Mass Index is warranted.

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.

Estilo de vida e fatores de risco associados ao aumento da gordura corporal de mulheres

Os objetivos eram descrever a associação entre índice de massa corporal (IMC, kg/m²), porcentagem de gordura e fatores de risco para doenças metabólicas; observar a prevalência da síndrome metabólica e relacionar às características de mulheres com sobrepeso e obesas. As voluntárias (n=50; IMC=31±6; idade=36±11 anos) eram avaliadas quanto ao exame clínico, medidas antropométricas, coletas de sangue e urina, gasto energético de repouso e registro alimentar. Fases em que se tornaram obesas em ordem decrescente: idade adulta, gravidez, adolescência, depois dos 40 anos e depois do casamento. O odds de ter um ou mais familiares obesos era de 316%. Eram ansiosas (60%), depressivas (12%), compulsivas (34%) e com distúrbios do sono (32%). O odds para dislipidemia era 28%, hipertensão, 25% e para glicemia acima de 100 mg/dL era de 35%. Elas estavam em déficit calórico, mas o balanço nitrogenado era positivo. A síndrome metabólica era presente em 25% delas e estava positivamente correlacionada a indicadores da gordura corporal e idade. A obesidade destas mulheres era multifatorial com influência familiar, podendo ter contribuições genéticas e ambientais. O equilíbrio físico/emocional parece ter influenciado neste processo.

Trends in the prevalence of childhood overweight and obesity in Australia between 1985 and 2008

BACKGROUND

Popular media, health experts and researchers talk about a paediatric 'obesity epidemic' with exponentially increasing rates of obesity and overweight. However, some recent reports suggest that prevalence may have plateaued. This study examined trends in the prevalence of Australian childhood overweight and obesity since 1985. Specifically, it aimed to determine whether there have been (a) overall increases in average body mass index (BMI), (b) differential patterns of change within age groups and (c) increases in BMI within each weight-status category.

METHOD

Forty-one Australian studies of childhood weight status conducted between 1985 and 2008 were reviewed. The studies included data on 264 905 Australians aged 2-18 years, with raw data being available on 70 758 children (27%). Children were classified as overweight or obese based on BMI using the criteria of Cole et al. (BMJ, 2000). The prevalence estimates were adjusted for age and sex, and plotted against measurement year using Lowess plots and two-linear-segment models. Where raw data were available, BMI z-scores (UK 1990 standard) were plotted against measurement year for all children and children in various age groups. Lowess plots and two-linear-segment models were used to assess secular trends in BMI z-scores pre- and post-1996 within age, gender and weight-status categories.

RESULTS

There has been a plateau, or only slight increase, in the percentage of boys and girls classified as overweight or obese, with almost no change over the last 10 years. In boys and girls, prevalence rates have settled around 21-25% for overweight and obesity together, and 5-6% for obesity alone. Similar trends were found for BMI z-scores. These patterns were fairly consistent across the age span. Within each weight-status category, average BMI has not increased.

CONCLUSIONS

Although levels of Australian paediatric overweight remain high, the prevalence of overweight and obesity seems to have flattened and has not followed the anticipated exponential trajectory.

Translating physical activity recommendations for overweight adolescents to steps per day

BACKGROUND

Steps/day guidelines for children aged 12 years and under are 12,000 to 16,000. There are limited reports in the literature on how many steps/day adolescents need to meet the 60-minutes/day moderate-to-vigorous physical activity (MVPA) recommendation. This study aimed to determine the steps/day that correctly classifies adolescents as meeting the 60-minute recommendation using objective measures.

METHODS

This analysis used data from 40 overweight (BMI M=31.5, SD=5.3) adolescents enrolled between 2005 and 2006 in a study to lose weight. Participants were aged 11 to 16 years (M=13.2, SD=1.2), 70.0% girls, and 52.6% non-Hispanic white, 23.7% Hispanic, and 23.7% other race/ethnicity. Participants wore an Actigraph accelerometer for up to 7 days that measured accelerations and step counts simultaneously. The age-adjusted Freedson equation was used to estimate physical activity-intensity minutes. Two criteria were used to define MVPA (3/6 and 4/7 METs). Analyses were conducted between 2008 and 2009.

RESULTS

Based on accelerometer data, approximately 48% and 10% of adolescents met the MVPA recommendation depending on the MVPA criteria. Adolescents who met phyiscial activity recommendation had higher MVPA min/day (p<0.001) and higher step counts (p<0.001), after adjusting for gender, age, and ethnicity. Receiver operating characteristic (ROC) curve analyses found that 9930 steps produced 0.84 sensitivity and 0.81 specificity (area under the curve [AUC] =0.89) and 11,714 steps produced 0.75 and 0.81 specificity (AUC=0.94) for meeting the recommendation using the 3/6 and 4/7 criteria, respectively.

CONCLUSIONS

Depending on the MVPA criteria used, these data suggest that overweight adolescents are likely to meet national MVPA recommendations if they accumulate between 10,000 and 11,700 steps per day.

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.

Imaging of acute appendicitis in children: EU versus U.S. ... or US versus CT? A European perspective

There is substantial evidence that imaging may reduce the negative appendectomy rate, also in children. However, controversy exists about the preferred method: US or CT, and the choice appears to be determined by the side of the Atlantic Ocean. This review brings forth several arguments in favour of US.

Revisiting "how many steps are enough?"

With continued widespread acceptance of pedometers by both researchers and practitioners, evidence-based steps/day indices are needed to facilitate measurement and motivation applications of physical activity (PA) in public health. Therefore, the purpose of this article is to reprise, update, and extend the current understanding of dose-response relationships in terms of pedometer-determined PA. Any pedometer-based PA guideline presumes an accurate and standardized measure of steps; at this time, industry standards establishing quality control of instrumentation is limited to Japan where public health pedometer applications and the 10,000 steps.d slogan are traceable to the 1960s. Adult public health guidelines promote > or =30 min of at least moderate-intensity daily PA, and this translates to 3000-4000 steps if they are: 1) at least moderate intensity (i.e., > or =100 steps.min); 2) accumulated in at least 10-min bouts; and 3) taken over and above some minimal level of PA (i.e., number of daily steps) below which individuals might be classified as sedentary. A zone-based hierarchy is useful for both measurement and motivation purposes in adults: 1) <5000 steps.d (sedentary); 2) 5000-7499 steps.d (low active); 3) 7500-9999 steps.d (somewhat active); 4) > or =10,000-12,499 steps.d (active); and 5) > or =12,500 steps.d (highly active). Evidence to support youth-specific cutoff points is emerging. Criterion-referenced approaches based on selected health outcomes present the potential for advancing evidence-based steps/day standards in both adults and children from a measurement perspective. A tradeoff that needs to be acknowledged and considered is the impact on motivation when evidence-based cutoff points are interpreted by individuals as unattainable goals.

A cluster-analytical approach towards physical activity and eating habits among 10-year-old children

The purpose was to investigate whether clusters-based on physical activity (PA) and eating habits-can be found among children, and to explore subgroups' characteristics. A total of 1725 10-year olds completed a self-administered questionnaire. K-means cluster analysis was based on the weekly quantity of vigorous and moderate PA, the excess index (weekly consumption of sugar and/or fat) and the daily diversity index. Chi-squares tested gender differences in clusters and associations with socio-economic status (SES), overweight, controlling for gender. Following distribution was reliable: Sporty Healthy Eaters (n=242; high vigorous PA, average moderate PA, low excess, higher diversity), Sporty Mixed Eaters (n=288; high overall PA, very high excess, high diversity), Moderate Active Healthy Eaters (n=221; average vigorous PA, highest moderate PA, lower excess, higher diversity), Unsporting Unhealthy Eaters (n=276; below average on all indexes, diversity extremely low) and Sedentary Healthy Eaters (n=318; lowest overall PA, higher excess, highest diversity). The Sporty Healthy Eaters and Sporty Mixed Eaters comprised more males, Sedentary Healthy Eaters more females. No associations with SES or overweight were found for the clusters. Co-occurrence of healthy and unhealthy behaviour exists. Only Sporty Healthy Eaters combine high levels of PA with low excess index and higher dietary diversity index. Effective ways of directing children to selective, individual relevant recommendations should be developed.

Physical activity of Canadian and American children: a focus on youth in Amish, Mennonite, and modern cultures

Childhood obesity is an urgent public health problem in North America and throughout most of the industrialized world. Diminishing levels of physical activity and the growth of sedentary pursuits may be contributing to the obesity epidemic. The advent of modern technological societies has brought about dramatic changes in lifestyle over the past century. To gain insights into physical activity levels in pre-industrial era societies, researchers have turned to studying religious groups that have resisted the lure of technological change. Children in Old Order Amish and Old Order Mennonite communities of North America have a lifestyle that still involves walking to school and friends' homes, performing chores, caring for farm animals, and active play. Research has shown that Amish and Mennonite children have higher levels of physical activity than modern-living children, despite less participation in organized competitive sports. As a result, Amish and Mennonite children tend to be leaner than their counterparts in contemporary society. Studying non-mainstream cultures can provide a valuable perspective on human behaviors.

Differences in physical activity by gender, weight status and travel mode to school in Cypriot children

OBJECTIVE

More information about children's physical activity during different periods of the day is needed. The purpose of this study was to describe children's physical activity during the segmented school day and examine potential differences during different periods of the day across gender, travel mode to school and weight status.

METHODS

School children (N=247) wore pedometers for four consecutive school days and recorded their steps during the before school period, the 20-min school break, the whole school period, the after school period and for the whole day. Children also reported how they traveled to school. Data were collected in Cyprus, in January/February of 2007.

RESULTS

T-tests indicated that boys took significantly higher steps than girls throughout all the segments of the day (p<0.001) and children who walked to school exhibited higher step counts during the before school period (p<0.001), the after school period (p<0.01), and the whole day (p<0.01) in comparison to children who used motorized transport. A three-way ANOVA revealed significant two-way interactions between weight status and travel mode to school.

CONCLUSION

Results suggest that there is a need to promote physical activity among children, especially among girls. Promoting active transport to school may further enhance the effectiveness of intervention programs.

Understanding school-age obesity: through participatory action research

PURPOSE

This study aimed to assess current levels of overweight (obesity) and fitness among school students using objective data.

METHODS

School-based action research teams were recruited statewide by the New Hampshire Healthy Schools Coalition, the state team of the National Action for Healthy Kids Coalition. Action teams consisted of a physical education teacher, a school nurse, and a school administrator. Data were collected from 6,511 student participants aged 6 to 14 years, which was a representative cross-section from New Hampshire school districts. Key variables of interest in the study were body mass index, and ability to pass five fitness tests using FITNESSGRAM. Pearson's correlation was used to assess the relationships among body mass index, age, gender, and the percent of students that passed FITNESSGRAM tests.

RESULTS

The ability of participants to pass the FITNESSGRAM tests declined markedly with age and differed between boys and girls, although the healthy fitness zones for any particular test was lower for girls. Body mass index was significantly negatively correlated with performance on all tests. Age was also statistically negatively correlated with performance on all tests; the relationship between gender and performance on the tests was less striking.

CLINICAL IMPLICATIONS

Results reflected an increase in the prevalence of overweight school children, even in New Hampshire, which is purported to be one of the healthiest states in the nation. Results offered evidence that body mass index is a valid proxy measure for fitness levels and that fitness programs are necessary to effectively combat the obesity epidemic. Evidence-based changes need to be implemented to address obesity-related factors in schools, because children spend many of their waking hours in that setting. Physical activity during recess and physical education classes could help to increase energy expenditure and develop sound minds and bodies. Schools should consider the development of school-based wellness teams to advise and advocate improved school-based wellness policies. School nurses can take an active part in these initiatives.

Evaluation of youth pedometer-determined physical activity guidelines using receiver operator characteristic curves

OBJECTIVE

Evidence-based pedometer guidelines have not been sufficiently validated in youth. The purpose of this paper was to evaluate the utility of current pedometer-determined physical activity guidelines for youth.

METHODS

Participants (n=812, mean age 9.7 years) were from two Midwestern communities during Fall 2005. Participants completed 7 days of pedometer monitoring using a Digiwalker 200-SW. ROC analyses were utilized to assess the utility of the cutpoints in reference to weight status. The percentage of subjects meeting physical activity recommendations (steps/day) was determined using two published recommendations.

RESULTS

The mean (SD) steps/day for boys, girls, and sexes combined were 12,709 (3,384), 10,834 (2562), and 11,665 (3028), respectively. Depending on the recommendation, approximately 55-75% of children did not meet the recommended number of steps/day. Sensitivity was high and specificity was low for both current guidelines evaluated. The ROC analysis indicated that lowering the steps/day cutpoint for boys and girls may increase accuracy.

CONCLUSIONS

This study demonstrates that a large percentage of children from two Midwestern communities do not meet current pedometer-based physical activity recommendations. Because the percentage of children categorized as active or inactive depends on the criteria that are employed, it is recommended that researchers select cutpoints based on the preferred context of application.

Training health care professionals to manage overweight adolescents: experience in rural Georgia communities

CONTEXT

The obesity epidemic threatens the present and future health of adolescents in the United States. Yet, health care providers lack specific training for pediatric obesity assessment and management.

PURPOSE

This study examined the adherence of rural Georgia primary care practitioners to an overweight adolescent management protocol. The study also documented the prevalence of obesity-associated physiological and behavioral risk factors among overweight adolescent patients.

METHODS

Ten rural clinics (58 providers) were recruited and received a 90-minute adolescent overweight assessment and management training session. Select biochemical, dietary, physical activity, and physical inactivity behaviors were assessed in overweight adolescent patients. Medical charts were abstracted to assess practitioner compliance with an overweight assessment protocol and patient adherence to a 16-week follow-up visit.

FINDINGS

Providers were receptive to training and complied with the recommended protocol. Eighty-five overweight adolescents were assessed, but only 49 (57%) completed the scheduled 16-week follow-up visit. Physical, biochemical, and behavioral assessments revealed that 13%-27% of the participants had abnormal levels of lipids, fasting glucose, and glucose/insulin ratio, and 80.5% had waist circumferences above the 90th percentile.

CONCLUSIONS

Practitioners complied with the assessment and follow-up protocol, leading to the discovery of previously unrecognized risk factors in many overweight adolescent patients. Lack of patient adherence to follow-up was the greatest limiting factor for obesity management. Further efforts are needed to implement and evaluate training to improve the management of adolescent overweight, especially in rural communities.

Effect of supervised exercise intervention on metabolic risk factors and physical fitness in Chinese obese children in early puberty

The aim of this paper was to study the effect of long-term supervised exercise-induced weight maintenance on metabolic risk factors and physical fitness in obese children in early puberty. A total of 49 obese children aged 12-14 years were divided into control and exercise groups. The children in the exercise group accepted exercise intervention supervised by a professional sports teacher for 9 of the 12 months. All participants in both groups received health education once every 3 months. Anthropometry and fasting serum lipids, glucose, insulin and homeostatic model assessment for insulin resistance (HOMA-IR) were measured at months 0, 3, 9, 12 of the intervention. Physical fitness was determined before and after intervention. After the intervention (i) BMI was reduced by 0.6 (P < 0.05) in the exercise group, but increased by 0.5 (P < 0.05) in the control group, compared with the pre-intervention level at the end of 9-month intervention; (ii) Triglyceride levels in the exercise group significantly decreased by 23.1% by 3 months (P < 0.05), and by 30.2% after 9 months (P < 0.05), but increased by 50% (P < 0.05) in the control group; high density lipoprotein-cholesterol (HDL-C) decreased more by 35% (P < 0.05) in the controls than in the exercise group (P < 0.05); (iii) Fasting serum glucose, insulin level and HOMA-IR decreased, respectively, by 23.1%, 36.6% and 48.5% in the exercise group at 9 months (P < 0.05), whereas glucose levels increased by 10.9% (P < 0.05) in the control group; (iv) Exercise performance, such as upper- and lower-limb strength, flexibility and endurance, were enhanced by 17.9%, 12.3%, 22.3% and 20.4% (P < 0.01), respectively and (v) At 12 months, i.e. 3 months after terminating the supervised exercise, serum triglycerides, glucose, insulin and HOMA-IR level all returned to the pre-intervention level. Supervised decrement exercise can effectively slow the progress of obesity, improve insulin sensitivity and metabolic risk factors, but once the supervised exercise is stopped, the health benefits weaken or vanish. The key to helping these obese children is for them to cultivate good exercise habits which are sustained throughout their lives.

Pedometer-determined physical activity and active transport in girls

BACKGROUND

It is well established that the risk of insufficient physical activity is greater in girls than in boys, especially during the adolescent years. The promotion of active transport (AT) to and from school has been posited as a practical and convenient solution for increasing girls' total daily activity. However, there is limited information describing the associations between AT choices and girls' physical activity across a range of age, ethnic, and socioeconomic groups. The objectives of this study were to (1) investigate physical activity patterns in a large multiethnic sample of female children and adolescents, and to (2) estimate the physical activity associated with AT to and from school.

METHODS

A total of 1,513 girls aged 5-16 years wore sealed multiday memory (MDM) pedometers for three weekdays and two weekend days. The ethnic composition of this sample was 637 European (42.1%), 272 Pacific Island (18.0%), 207 East Asian (13.7%), 179 Maori (11.8%), 142 South Asian (9.4%), and 76 from other ethnic groups (5%). Pedometer compliance and school-related AT were assessed by questionnaire.

RESULTS

Mean weekday step counts (12,597 +/- 3,630) were higher and less variable than mean weekend steps (9,528 +/- 4,407). A consistent decline in daily step counts was observed with age: after adjustment for ethnicity and SES, girls in school years 9-10 achieved 2,469 (weekday) and 4,011 (weekend) fewer steps than girls in years 1-2. Daily step counts also varied by ethnicity, with Maori girls the most active and South Asian girls the least active. Overall, 44.9% of participants used AT for school-related travel. Girls who used AT to and from school averaged 1,052 more weekday steps than those who did not use AT. However, the increases in steps associated with AT were significant only in older girls (school years 5-10) and in those of Maori or European descent.

CONCLUSION

Our data suggest that adolescent-aged girls and girls of Asian descent are priority groups for future physical activity interventions. While the apparent benefits of school-related AT vary among demographic groups, promoting AT in girls appears to be a worthwhile strategy.

Physical activity of young children: a two-year follow-up

Inadequate physical activity in children is a major health concern. The purpose of this study was to examine changes in physical activity of boys and girls, between 6-8 and 8-10 years of age and how activity patterns correlated with selected family, child, and environment factors. The sample included 59 children without motor delays (26 boys and 23 girls) between 8 and 10 years of age. Twenty-two of the children participated in a previous study at 6-8 years of age. Parents completed a questionnaire on their children's non-physical and physical activities. Children wore a pedometer during two weekdays and two weekend days. The results indicate that girls spent more time on homework and reading and on crafts and indoor play than boys. Girls spent more time on musical and cultural activities and boys spent more time on screen-based activities at 8-10 years of age. Children spent significantly less time on physical activity at 8-10 years of age. Boys took more steps per day than girls on weekends. The average number of steps taken per weekday increased for boys, but not girls, at 8-10 years of age. There was an inverse relationship between body mass index and number of steps taken per day (weekdays r = -.28; weekend r = -.32). Socioeconomic status was associated with the number of steps taken by children on weekends (r = .34). The results have implications for physical activities for girls and school and community programs for children.