Validation of the Physical Activity Questions in the World Health Organization Health Behavior in School-Aged Children Survey Using Accelerometer Data in Japanese Children and Adolescents

Association between maternal physical activity from pre-pregnancy to child-rearing and their children's physical activity in early childhood among Japanese

INTRODUCTION

This study aimed to determine the association between cumulative maternal physical activity level and their children's physical activity in early childhood. We also compared the influence of each maternal physical activity on children's physical activity in early childhood.

METHODS

We analyzed the data from 1,067 Japanese mother-child pairs. Maternal physical activity was assessed using the International Physical Activity Questionnaire. Cumulative physical activity level in mothers was computed based on the categories (low, moderate, and high) of physical activity from 5 time points (pre-pregnancy, during pregnancy, 1.5, 3.5, and 5.5 years postpartum). Children's physical activity level was measured at age 5.5 years using the WHO Health Behaviour School-aged Children questionnaire and defined as engaging in physical activity for at least 60 minutes per day for more than 5 days. Logistic regression analysis was used to determine the association between maternal and children's physical activity levels.

RESULTS

The results showed the positive association between cumulative maternal physical activity and children's physical activity level (P for trend < 0.001). Furthermore, maternal physical activity during pregnancy (P for trend = 0.031) and 5.5 years postpartum (P for trend < 0.001) was positively associated with children's physical activity.

CONCLUSION

A positive association was observed between the cumulative maternal physical activity level and the physical activity level of their children at 5.5 years of age. Furthermore, maternal physical activity during pregnancy and at 5.5 years postpartum were positively associated with the level of children's physical activity.

School-aged children's movement behaviours and subjective health complaints in Japan: a cross-sectional study during COVID-19 pandemic-related school closures and after school reopenings

BACKGROUND

Social restrictions associated with the COVID-19 pandemic have altered children's movement behaviours and impacted their mental health. However, the influence of social restrictions on subjective health complaints remains inadequately understood. This study compared adherence to 24-hour movement behaviour guidelines and the prevalence of subjective health complaints during school closure and one year after reopening. We also examined how combinations of adherence to movement behaviour recommendations relate to subjective health complaints.

METHODS

A repeated cross-sectional survey was conducted at two points. The first survey in May 2020 included 1535 (766 boys and 769 girls) participants during school closures, while the second survey from May to July 2021 involved 1125 (583 boys and 542 girls) participants one year after school reopening. The questionnaire covered socio-demographics, physical activity, screen time, sleep, and subjective health complaints. Differences between periods were analysed using chi-square tests. Logistic regression models assessed the association between adherence to guidelines and subjective health complaints.

RESULTS

During school closure, children were more likely to meet 'only sleep' recommendations and have irritability and lethargy symptoms. Irrespective of sex, those adhering to two or all three recommendations (excluding physical activity and screen time) had a lower risk of symptoms related to physical and mental pain, fatigue, irritability, and lethargy as compared to those who met none of the recommendations.

CONCLUSIONS

Children should meet at least one physical activity or screen time recommendation in addition to sleep recommendations for subjective health. Strategies considering the priority of each movement behaviour are crucial, even during abnormal situations, such as pandemic-related social restrictions. This study offers insightful findings concerning children's mental health issues during unprecedented and massive disasters or crises.

Impact of the COVID-19 Pandemic on the Socioeconomic Inequality of Health Behavior Among Japanese Adolescents: A 2-Year Repeated Cross-Sectional Survey

BACKGROUND

Although disparities in socioeconomic status in health behaviors have been highlighted globally, they are not well understood in Japanese adolescents. The purpose of this study was to clarify the changes in socioeconomic disparities in adolescents' fundamental health behaviors, such as physical activity, screen time (ST), sleep, breakfast intake, and bowel movement before and during COVID-19.

METHODS

This was a repeated cross-sectional study which used data from the 2019 and 2021 National Sports-Life Survey of Children and Young in Japan. Data of 766 and 725 participants in 2019 and 2021, respectively, were analyzed. Favorable health behaviors were defined as daily moderate to vigorous physical activity (MVPA) of at least 60 minutes, ST of less than 2 hours, sleep of 8 to 10 hours, daily breakfast intake, and bowel movement frequency of at least once in every 3 days. We calculated the slope index of inequality and relative index of inequality in each health behavior for equivalent household income levels for assessing absolute and relative economic inequalities.

RESULTS

Compliance with MVPA and ST recommendation significantly declined from 20.1% and 23.0% in 2019 to 11.7% and 14.9% in 2021, respectively. The slope index of inequality and relative index of inequality increased in MVPA for income levels, but decreased in daily breakfast in 2019 to 2021. Although the widening and narrowing of the disparity were inconclusive for ST, it exacerbated for the higher-income groups.

CONCLUSIONS

Our study revealed widening of economic disparities in the achievement of recommended MVPA and narrowing of it in breakfast intake among adolescents before and during COVID-19.

Results from the Japan 2022 report card on physical activity for children and youth

Background/Objective: The 2020 Tokyo Olympics and Paralympic was held in 2021, although postponed due to the spread of COVID-19. This event might have an impact on physical activity (PA) of children and adolescents, but the national data on PA during the pandemic were not available. Therefore, the goal of the 2022 Japan Report Card on Physical Activity for Children and Youth (The 2022 Japan Report Card) is to assess and track levels of health behaviors related to PA, and health outcomes in Japanese children and adolescents, and environments and government strategy for PA just before the pandemic.

Methods

The 2022 Japan Report Card consists of health behaviors and outcomes (8 indicators), and influences on health behaviors (4 indicators). Nationally representative data were used to score the indicators.

Results

The key five health behaviors and outcomes (Overall PA: B⁻; Organized Sport: B⁻; Active Transportation: A⁻; Physical fitness: B, Weight status: A) were favorable. Sedentary Behavior and Sleep received C⁻ and D⁻ grades, respectively. Active Play could not be graded (INC). In the influences domain, Family and Peers was graded as C⁻, while School (B⁺), Community and Environment (B), and Government (B) were favorable.

Conclusions

The 2022 Japan Report Card shows that Japanese children and adolescents had favorable levels of overall PA, active transportation to and from school, and weight status, and there was a generally favorable environment for PA and health, though sedentary behavior and sleep were unfavorable. Future nationally representative surveys on active play are needed.

The impact of ActiGraph's low-frequency extension filter on measurement of children's physical activity

This study examines differences in accelerometer-based measurements of children's movement with and without applying ActiGraph's low-frequency extension (LFE) filter. Thirty children wore ActiGraph GT9X devices during structured physical activity (PA) periods. Raw accelerometry data for each activity period were processed with and without the LFE filter applied. For each activity period, paired t-tests were used to compare vector magnitude counts and minutes spent in moderate-to-vigorous physical activity (MVPA) with and without the LFE filter applied. Repeated measures MANOVA models were used for compositional data analysis of the percentage of time spent in sedentary behaviour and light, moderate, and vigorous PA with and without the LFE filter applied. Applying the LFE filter significantly increased vector magnitude counts and estimated minutes spent in MVPA for all activity periods when compared to the normal filter. For brisk walking, the LFE filter had a significant impact on the composition of time spent in sedentary behaviour and PA intensities. Children's activity data processed with the LFE filter may not be compatible with cut-points for activity levels developed with the normal filter, and caution should be taken when comparing children's activity levels or movement data between studies that do and do not use the LFE filter.

Compliance with a physical activity guideline among junior high school students

BACKGROUND

There were no nationwide moderate- to vigorous-intensity physical activity (MVPA) data relating to Japanese adolescents. This study assessed compliance with an MVPA guideline by adolescents, using a random sampling survey in Japan. The factors associated with compliance with the guideline were also examined.

METHODS

Participants were first- to third-grade Japanese junior high school students (307 boys and 255 girls). We analyzed data from the National Sports-Life Survey of Teens 2019, which used the Japanese version of physical activity (PA) questions in the World Health Organization Health Behavior in School-aged Children survey and potential correlates of MVPA.

RESULTS

Compliance with the PA guideline by the World Health Organization for Japanese students was 19.0% (95% confidence interval (CI), 15.8-22.3). The compliance of boys was significantly higher than that of girls (23.1%; 95% CI, 18.4-27.8; vs 14.1%; 95% CI, 9.8-18.4). The odds of meeting the PA guideline were significantly higher for boys in the second grade than boys in the first grade (odds ratio (OR) 1.78; 95% CI, 1.02-3.09), liking PA (for all: OR: 2.97; 95% CI, 1.32-6.69; for girls: OR: 2.99; 95% CI, 1.01-8.81), and sports participation (for all: OR: 4.77; 95% CI, 2.32-9.80; for boys: OR: 6.00; 95% CI, 1.81-19.89; for girls: OR: 4.08; 95% CI, 1.63-10.21).

CONCLUSIONS

The results suggest that more than 80% of junior high school students were insufficiently physically active in Japan. Preferences for PA and sports participation may be important correlates of sufficient PA.

Koshu GRoup Activity, Active Play and Exercise (GRAPE) Study: A Cluster Randomised Controlled Trial Protocol of a School-Based Intervention among Japanese Children

School-based programmes need to be effective, easy for all, easy to perform within a short duration, and inexpensive. However, no studies have reported whether voluntarily and very short-time active play programmes contribute to improved health outcomes. This study aims to describe the GRoup activity, Active Play and Exercise (GRAPE) cluster randomised controlled trial that examined whether active play interventions of very short durations contribute to increasing physical activity (PA) and bone mass among school-aged children. The trial was conducted in 2018 from January to June, and the activity comprised ≥2 children jumping together for approximately 10 s per session, at least five times a day (approximately 1 min/day). School clusters, pair-matched as per school size (total number of children) and region, were randomly allocated to either intervention or wait-list control groups. The primary outcomes comprised objectively measured changes in PA levels (moderate-to-vigorous PA) evaluated using wrist-worn activity trackers from baseline to the one-year follow-up (six-month post-intervention follow-up) and changes in bone mass evaluated using calcaneus quantitative ultrasound parameters. This study could describe the problems and challenges in school-based PA intervention studies and present findings that could make a potentially important contribution to health education and PA promotion.