We compared 24-hour waist-worn accelerometer wear time characteristics of 9-11 year old children in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) to similarly aged U.S. children providing waking-hours waist-worn accelerometer data in the 2003-2006 National Health and Nutrition Examination Survey (NHANES).Valid cases were defined as having ≥4 days with ≥10 hours of waking wear time in a 24-hour period, including one weekend day. Previously published algorithms for extracting total sleep episode time from 24-hour accelerometer data and for identifying wear time (in both the 24-hour and waking-hours protocols) were applied. The number of valid days obtained and a ratio (percent) of valid cases to the number of participants originally wearing an accelerometer were computed for both ISCOLE and NHANES. Given the two surveys' discrepant sampling designs, wear time (minutes/day, hours/day) from U.S. ISCOLE was compared to NHANES using a meta-analytic approach. Wear time for the 11 additional countries participating in ISCOLE were graphically compared with NHANES.491 U.S. ISCOLE children (9.92±0.03 years of age [M±SE]) and 586 NHANES children (10.43 ± 0.04 years of age) were deemed valid cases. The ratio of valid cases to the number of participants originally wearing an accelerometer was 76.7% in U.S. ISCOLE and 62.6% in NHANES. Wear time averaged 1357.0 ± 4.2 minutes per 24-hour day in ISCOLE. Waking wear time was 884.4 ± 2.2 minutes/day for U.S. ISCOLE children and 822.6 ± 4.3 minutes/day in NHANES children (difference = 61.8 minutes/day, p < 0.001). Wear time characteristics were consistently higher in all ISCOLE study sites compared to the NHANES protocol.A 24-hour waist-worn accelerometry protocol implemented in U.S. children produced 22.6 out of 24 hours of possible wear time, and 61.8 more minutes/day of waking wear time than a similarly implemented and processed waking wear time waist-worn accelerometry protocol. Consistent results were obtained internationally. The 24-hour protocol may produce an important increase in wear time compliance that also provides an opportunity to study the total sleep episode time separate and distinct from physical activity and sedentary time detected during waking-hours.ClinicalTrials.gov NCT01722500 .
PURPOSE: To develop sex- and age-specific international normative 20 m shuttle run test (20mSRT) values for children and youth (aged 9-17 years), and to estimate the prevalence meeting the FITNESSGRAM® criterion-referenced standards for healthy cardiorespiratory endurance. METHODS: A systematic literature search was undertaken to identify papers explicitly reporting descriptive 20mSRT (with 1-minute stages) data on children and youth since 1981. Data were included on apparently healthy (free from known disease/injury) 9-17 year-olds. Following corrections for methodological differences, pseudo data were generated using Monte Carlo simulation, with population-weighted sex- and age-specific normative centile values generated using the LMS method. Sex- and age-related differences were expressed as percent and standardized differences in means. The prevalence of children and youth with healthy cardiorespiratory endurance was estimated using the age- and sex-specific FITNESSGRAM® criterion-referenced standards. RESULTS: Normative values were displayed as tabulated centiles for the 20mSRT using four common metrics (speed [km/h] at the last completed stage, completed stages, laps, and mass-specific peak oxygen uptake) on a dataset comprising 850,036 test performance scores from 48 countries extracted from 159 reports. Boys consistently outperformed girls at each age group (mean difference ±95%CI: 0.99 ±0.35 km/h or 0.81 ±0.21 standardized units), with the magnitude of age-related increases larger for boys than for girls. Boys (mean ±95%CI: 68 ±13%) had healthier cardiorespiratory endurance than girls (mean ±95%CI: 52 ±18%), with the prevalence of healthy cardiorespiratory endurance decreasing systematically with age. CONCLUSION: This study provides the most comprehensive and up-to-date set of international sex- and age-specific normative 20mSRT values for children and youth. We envision these results as a useful tool for coaches, physical educators, health practitioners, and public health workers as a surveillance, profiling, and/or screening instrument to help identify over- and under-performing children and youth.
Despite evidence linking physical activity during childhood to later health outcomes, physical education programs in elementary and middle schools have slowly been eroded during the past two decades. Many educators and parents believe that the time and money spent on physical activity during school hours might be better spent on academic pursuits. This Brief provides a summary of three relevant longitudinal studies, and a recent study by Tremblay, Inman, and Willms (in press) which examined the relationships among children’s self-esteem, levels of physical activity, body-mass index, and academic achievement. The data were collected from the full population of grade 6 students in New Brunswick in 1996, as part of the Elementary School Climate Study. The findings indicate that the concern that physical activity has a deleterious effect on achievement is not well founded. Moreover, increased physical activity has important positive effects on self-esteem and physical health, which in the longer term may contribute to academic success. ▸ The leading cause of death in Canada is heart disease. Three of the most important modifiable risk factors for heart disease are poor nutrition, smoking, and a lack of physical activity. The evidence linking physical activity and health is stronger for adults than for children; however, the likelihood of being active as an adult is influenced by habits established during childhood.
No abstract is provided for this article.
Commentary on: M Wake, LA Baur, B Gerner, et al.. Outcomes and costs of primary care surveillance and intervention for overweight or obese children: the LEAP 2 randomised controlled trial. BMJ2009;339:b3308.
While we concur with the objectives of the recent International Journal of Behavioural Nutrition and Physical Activity paper published by Jago and colleagues titled "Physical activity and sedentary behaviour typologies of 10-11 year olds", we feel that the results as currently presented do not support their conclusions. Though the authors created groups of children with dramatically different patterns of self-reported physical activity and sedentary behaviour, an inspection of the objectively measured accelerometry data shows little difference between the groups. Further, in at least one instance the difference between groups was of the opposite direction when using objective measures, as opposed to the self-report measures used in the published analysis. Thus, we caution the authors from making conclusions based on their self-report data, and propose that they re-analyze their data using their objectively measured data instead.
Differences in physical activity are thought to contribute to disparities in childhood obesity rates among industrialized nations. In addition, declining levels of physical activity may be contributing to the increasing rates of childhood obesity found in most modern societies. Thus, it is interesting to study activity levels in a group that refrains from using modern technology. PURPOSE: To obtain objective measurements of physical activity and body mass index (BMI) in Old Order Amish children living in Ontario, Canada. METHODS: 139 children (6–18 years of age) were recruited for the study. Height and body mass were measured at five 1-room schoolhouses. The school-age children wore sealed Yamax SW-200 pedometers for 7 days, and on each school day, research assistants opened the pedometers, recorded steps, re-sealed them, and placed them back on the children. Amish schools end after 8th grade, so we asked the older children to record their steps on a pedometer log sheet. RESULTS: The average steps per day (mean + SE) are shown below:TableTwo-way ANOVAs showed significant gender effects for all 3 of the step variables (P <0.001), but no significant age effects. There was also a trend towards a significant age × gender interaction for weekday steps (P=0.089). Overall, 7.2% of the children were overweight, and 1.4% were obese, according to the new definitions of child overweight and obesity (Cole TJ et al., British Medical Journal, 2005). CONCLUSION: The Amish children had high levels of pedometer-measured activity, and low rates of obesity. By comparing our results to those of studies conducted in modern societies on three continents, it appears that these Amish children are more physically active and have lower rates of obesity than children living in modern, industrialized societies.
Self-reported leisure-time physical activity levels (LTPA) vary geographically across Canada and this variability may be partially explained by seasonal patterns. Despite having climatic seasonal variations that differ significantly across the country, relatively little is known about the seasonal variation of LTPA in provinces across Canada. Purpose To examine the seasonal variation pattern of LTPA, by province and territory, in Canada. Methods Pooled data from cycles 1.1 (2000/01) and 2.1 (2003) of the cross-sectional Canadian Community Health Survey (ages 20+yrs; N=230,679) were used for this study. Weighted prevalences of LTPA (≥1.5 kcal/kg/day (kkd), moderately active; ≥3 kkd, active; ≥6 kkd, very active) were calculated by month and by season (Spring, Summer, Fall, Winter) for each province (10) and the territories combined (1). Bootstrap variance estimation was done where necessary. Adjusted and unadjusted multiple logistic regressions were also run to quantify the effects of season, province and province-season interactions on being physically active (≥1.5 kkd, ≥ 3 kkd, ≥6 kkd) while controlling for age, sex, marital status, education, employment status, children in the home, smoking status and BMI. To confirm that the seasonality trend of each province was statistically similar (parallelism hypothesis) a profile analysis was completed using the F-test. Results The proportion of Canadians who report being physically active (≥3 kkd) varies significantly across seasons with summer the highest (28.1%, p < 0.05) and winter the lowest (15.7%, p < 0.05). Significant provincial variation was also observed with BC the highest (29.6%) and NF the lowest (16.6%), and a general trend of declining activity prevalences from west to east. Despite substantial provincial variation, the seasonal variation within each province follows a similar pattern, with only minor province-season interactions, even when different levels of activity were assessed (≥1.5 kkd, ≥ 3 kkd, ≥6 kkd). Generally, younger age groups (aged 20–34), men, non-smokers, singles/never-married, individuals of acceptable weight (BMI ≥ 25), those with some post-secondary education or higher, those who did not work and individuals without children have increased odds of being physically active. Conclusion These results confirm that there is significant seasonal and provincial variation in Canada and add evidence that within each province the seasonal variation pattern is very similar.
There is a lack of research on meeting 24-hour movement guidelines, including physical activity (PA), sedentary time (ST) and sleep, among Chinese children and adolescents. PURPOSE: To investigate the prevalence of meeting the 24-hour movement guidelines, related correlates, or the relationships with body mass index (BMI) among Chinese children and adolescents. METHODS: Cross-sectional data were derived from the Physical Activity and Fitness in China—The Youth Study (PAFCTYS) 2017. A nationally representative sample with 114,072 children and adolescents (9-18 years-old, mean age 13.75 years, 49.2% boys) completed a self-report questionnaire regarding PA, ST and sleep. The prevalence of meeting the 24-hour movement guidelines and World Health Organization (WHO) weight status categories was determined. Generalized linear models were used to determine the correlates of meeting the movement guidelines and the relationships of meeting the movement guidelines with overweight and obesity (OW/OB). RESULTS: Only 5.12% of Chinese children and adolescents met the 24-hour movement guidelines and 22.44% were classified as OW/OB. Children and adolescents meeting the 24-hour movement guidelines showed lower odds ratios for OW/OB. Compared with meeting the 24-hour movement guidelines, boys of 4-6th grades (9-12 years old) meeting none of the recommendations (OR = 1.22), ST recommendation only (OR = 1.13) and sleep recommendation only (OR = 1.14) had significantly higher odds ratios for OW/OB. Similar trends were observed in girls of 4-6th grades meeting none of the recommendations (OR = 1.35), sleep recommendation only (OR = 1.23) and PA + sleep recommendations (OR = 1.24), and in girls of 7-9th grades (13-15 years old) meeting none of the recommendations (OR = 1.30). CONCLUSIONS: Very few Chinese children and adolescents met the integrated health-related 24-hour movement guidelines. Age (negative), parental educational level and family income (both positive) were correlates of meeting the 24-hour movement guidelines. Children and adolescents meeting the 24-hour movement guidelines were more likely to have healthier body weight, especially in the youngest age group, and girls in middle age group. Funding: Supported by the General Project of the National Social Science Foundation of China (19BTY077).
