Different Methods Yielded Two-Fold Difference in Compliance with Physical Activity Guidelines on School Days

Before-school physical activity patterns among adolescents using accelerometer and GPS data

Most adolescents do not meet physical activity (PA) guidelines. The before-school segment has been identified as one promising opportunity for intervention; however, there is a need for contextual understanding of PA in this segment. This study aimed to examine: a) adolescents' PA levels across various locations before school (6:00am - school start), b) contributions of before-school PA to daily PA and PA guidelines, and c) correlates of location-specific before-school PA. A cross-sectional analysis was conducted using adolescents' (n = 148, mean age 14.7) accelerometer and GPS data. Adolescents averaged 9.7 min in before-school moderate-to-vigorous PA (MVPA), representing substantial contributions to daily activity. Most MVPA occurred away from home and school. Significant correlates included segment duration, age, socio-economic status, and PA self-efficacy. Future work should consider these patterns and correlates to support adolescents' PA through targeted interventions.

Influence of Guideline Operationalization on Youth Activity Prevalence in the International Children's Accelerometry Database

INTRODUCTION

The United Kingdom and World Health Organization recently changed their youth physical activity (PA) guidelines from 60 min of moderate- to vigorous-intensity PA (MVPA) every day, to an average of 60 min of MVPA per day, over a week. The changes are based on expert opinion due to insufficient evidence comparing health outcomes associated with different guideline definitions. This study used the International Children's Accelerometry Database to compare approaches to calculating youth PA compliance and associations with health indicators.

METHODS

Cross-sectional accelerometer data (n = 21,612, 5-18 yr) were used to examine compliance with four guideline definitions: daily method (DM; ≥60 min MVPA every day), average method (AM; average of ≥60 min MVPA per day), AM5 (AM compliance and ≥5 min of vigorous PA [VPA] on ≥3 d), and AM15 (AM compliance and ≥15 min VPA on ≥3 d). Associations between compliance and health indicators were examined for all definitions.

RESULTS

Compliance varied from 5.3% (DM) to 29.9% (AM). Associations between compliance and health indicators were similar for AM, AM5, and AM15. For example, compliance with AM, AM5, and AM15 was associated with a lower BMI z-score (statistics are coefficient [95% CI]): AM (-0.28 [-0.33 to -0.23]), AM5 (-0.28 [-0.33 to -0.23], and AM15 (-0.30 [-0.35 to -0.25]). Associations between compliance and health indicators for DM were similar/weaker, possibly reflecting fewer DM-compliant participants with health data and lower variability in exposure/outcome data.

CONCLUSIONS

Youth completing 60 min of MVPA every day do not experience superior health benefits to youth completing an average of 60 min of MVPA per day. Guidelines should encourage youth to achieve an average of 60 min of MVPA per day. Different guideline definitions affect inactivity prevalence estimates; this must be considered when analyzing data and comparing studies.

Temporal Trends in Children's School Day Moderate to Vigorous Physical Activity: A Systematic Review and Meta-Regression Analysis

BACKGROUND

Evidence from a limited sample of countries indicates that time for physical education and recess during school have declined. Schools are called to provide children with 30 minutes of moderate to vigorous physical activity (MVPA). This systematic review and meta-analysis estimated temporal trends in children's school day MVPA.

METHODS

Three online databases were searched to identify studies with objectively measured MVPA, during school hours, in school aged children (5-18 y). Multilevel random-effects meta-analyses estimated MVPA by year, and meta-regression analyses estimated temporal trends in school day MVPA.

RESULTS

Studies (N = 65) providing 171 MVPA estimates, representing 60,779 unique children, from 32 countries, and spanning 2003-2019 were identified. Most studies were conducted in North America (n = 33) or Europe (n = 21). School day MVPA ranged from 18.1 (95% confidence interval, 15.1-21.1) to 47.1 (95% confidence interval, 39.4-54.8) minutes per day in any given year. Meta-regression analyses indicated that MVPA declined from 2003 to 2010 (approximately 15 min decline), plateaued from 2010 to 2015 (approximately 1 min decrease), and increased from 2015 to 2019 (approximately 5 min increase).

CONCLUSIONS

School day MVPA decreased from 2003 to 2010 and has recently begun to increase. However, the majority of the evidence is from North America and Europe with some evidence from Oceania and very little evidence from Asia to South America.

Interactions with Home and Health Environments Discourage Physical Activity: Reports from Children with Complex Congenital Heart Disease and Their Parents

Children with complex congenital heart disease are less active than recommended for optimal health, with social and physical environments important determinants. The purpose of this study was to examine the physical activity perceptions of children with complex congenital heart disease and their parents to identify social and physical environment intervention targets. A semi-structured discussion guide elicited physical activity perceptions from children (26 boys, 19 girls, 6.0-12.4 years) with complex congenital heart disease (single ventricle n = 42) and their parents during three child and three parent focus groups and 41 interviews. Interviews and focus groups were audio-recorded and transcribed verbatim for inductive thematic analysis. Children and parents identified home, peer and health environments as impacting on their children's physical activity participation. Peer environments, such as school or daycare, were supportive by providing physical activity facilities and enabling fun with peers and time outdoors. At home, parent and sibling interactions both encouraged and discouraged physical activity. The children's unique health environment fostered physical activity uncertainty, discouraging activity despite minimal or no physician recommendations to restrict physical activity. Children with complex congenital heart disease and their parents recognize the importance of physical activity and fun with friends. Physical activity uncertainty contributes to their inactive lifestyles despite minimal restrictions from health professionals. Positive clinical encouragement and health environment interventions that better support physical activity are required.

Comparison between self-reported and accelerometer-derived measurements for classifying children and adolescents as physically active in Chile

The aim of this study was to compare self-reported with two accelerometer-derived methods to classify Chilean children and adolescents as physically active. In total, 247 students wore an accelerometer on their hips during 7 consecutive days to classify them as physically active based on (1) daily accumulation of ≥ 60 minutes of moderate-to-vigorous physical activity (MVPA) on each of the seven days, and (2) average MVPA ≥ 60 minutes/day. Also, participants were classified as physically active if they reported being active for at least 60 minutes in all seven days. When using the accelerometer data, 0.8% were active in all seven days, while 10.5% recorded ≥ 60 minutes MVPA per day on average. Based on self-report, 7.2% were physically active. The agreement between self-reported and accelerometer estimations were poor. Important differences were observed between the self-reported and device-derived methods for classifying children and adolescents as physically active. When comparing them, some considerations should be taken. The findings suggest that these methods are not interchangeable. Therefore, if possible, they should be used as complementary measurements.

Physical activity and sedentary time of youth in structured settings: a systematic review and meta-analysis

BACKGROUND

Structured settings, such as school, childcare, afterschool programs, summer camps, and physical activity/sport programs are crucial to promoting physical activity (PA) opportunities and reducing sedentary (ST) for children and adolescents. However, little is known about how much PA and ST children and adolescents accumulate in structured settings. The aim of this study is to conduct a systematic review and meta-analysis of the absolute amount of time youth spend physically active and sedentary in different structured settings (Prospero number: 42018111804).

METHODS

Observational and experimental/quasi-experimental studies (baseline data only) with full-text available, written in English and published in a peer-reviewed journal, reporting the total amount of objectively measured PA (light, moderate, vigorous, and/or total physical activity) and/or time spent ST during structured settings among youth (3 to 18 years) were eligible. Adjusted meta-analysis was conducted to estimate the pooled mean of time spent in PA and ST, by settings and sex.

RESULTS

A total of 187 studies (childcare n=60; school n=91; afterschool programs n=14; summer camp n=4; and Physical activity/ sport programs n=18) from 30 countries (47.9% United States), representing 74,870 youth (mean age 8.6 years old) were included. Overall, there was a high variation between studies in outcomes and settings. The meta-analyses revealed, on average, youth spend 221.8 minutes (36.7 min/hour) in ST and 32.1 minutes (5.1 min/hour) in MVPA during childcare hours, and 223.9 minutes (36.7min/hour) in ST and 27.8 min (4.4 min/hour) in MVPA at school. Relatively, youth are engaged in more MVPA in afterschool programs (11.7 min/hour), PA/ sport programs (20.9 min/hour), and summer camps (6.4 min/hour), when compared to childcare and school.

CONCLUSION

Total PA accumulated during childcare and MVPA accumulated during schools hours were close to recommendations, despite high proportion of ST. Afterschool programs, summer camp and PA/ sport programs are important settings that can contribute to daily PA and reduced ST. Ensuring all youth have access to these structured settings may be an important step forward for public health.

A Systematic Review of Children's Physical Activity Patterns: Concept, Operational Definitions, Instruments, Statistical Analyses, and Health Implications

Despite the widespread use of the expression “physical activity pattern” (PAP), there apparently is no general consensus regarding its definition. This systematic review aimed to examine available research focussing on (1) definitions of PAP, (2) instruments/techniques used to describe PAP, (3) statistical approaches used to analyse PAP, and (4) implications of PAP on children’s health. A systematic review of the available literature was done to identify studies published up to October 2019, and 76 studies were eligible. None of the studies presented a formal definition of PAP; a wide range of instruments were used to investigate children’s PAP, and most of the revised studies did not explicitly present a formal statistical model to define PAP. Twenty-four papers purported to examine associations between PAP and health indicators. The review highlights no consensus on a clear PAP definition whatever the instrument used to capture it, and we did not find any agreement regarding how best to analyse PAP. We suggest that PAP should be used when targeting the investigation of similarities/dissimilarities, as well as stabilities and/or changes in children’s PA at an intra-personal level. In sum, PAP should be used to best describe individual streams of behaviours, and not exclusively PA levels/intensities.

The participation in organised sport doubles the odds of meeting physical activity recommendations in 7-12-year-old children

The purpose of this study was to determine the contributing role of organised sport participation to daily physical activity (PA) and to describe the PA during training. Children aged 7-12 wore the accelerometer for 1 week. Children with activity data for a minimum of 5 days were included in the analysis (n = 492). Evenson cut-points were used to extract PA data for whole day and training sessions. Compliance with PA recommendations was assessed with two methods - weekly average and daily data. More than half (52.5%) of the children participated in an organised sport at least once a week. Participation in organised sport three or more times a week increased the odds of meeting PA recommendations (average method: OR = 4.02, 95% CI: 1.98-8.19, p < 0.001, days method: OR = 2.82, 95% CI: 1.35-5.88, p = 0.006). On average, children acquired 23.3 ± 15.3 min of moderate to vigorous PA (MVPA) during trainings, while boys accrued more MVPA minutes compared to girls (β = 5.2, 95% CI: 2.4-8.0) and the training time MVPA decreased with age (β = -1.0, 95% CI: -1.9 to -0.1), respectively. Each additional MVPA minute during training increased daily MVPA by 1.3 min (95% CI: 1.1-1.5). On days with training children accumulated 24.9 (95% CI: 21.8-28.0) more MVPA minutes compared to days without training. In conclusion, these findings highlight the importance of organised sport in supporting the PA levels of children. However, participation in the organised sport only is not sufficient to meet PA recommendations, and therefore, PA should be supported throughout the day.

Are We Overestimating Physical Activity Prevalence in Children?

Background: Physical activity guidelines state that children should achieve at least 60 minutes of moderate to vigorous physical activity (MVPA) on each day of the week. Accurate assessment of adherence to these guidelines should, ideally, include measurement over 7 days. When less than 7 days of data are available, researchers often report the average minutes of MVPA per day as a proxy for 7-day measurement. The aim of this study was to compare prevalence estimates generated by average MVPA per day versus MVPA assessed over 7 days. Methods: Data were collected as part of the Healthy Lifestyles Programme. One class from each school was randomized to wear a GENEActiv accelerometer for 8 days. The percentages of children achieving an average of ≥60 minutes of MVPA per day and those achieving ≥60 minutes of MVPA on each of 7 days were calculated. Results: A total of 807 children provided 7 days of data. When the average MVPA per day was calculated, 30.6% (n = 247) of children accumulated ≥60 minutes of MVPA per day. Only 3.2% (n = 26) accumulated ≥60 minutes of MVPA on every day of the week. Conclusion: Previous studies utilizing average MVPA per day are likely to have overestimated the percentage of children meeting recommendations.

Assessment of exposure to air pollution in children: Determining whether wearing a personal monitor affects physical activity

Personal air pollution monitoring in research studies should not interfere with usual patterns of behavior and bias results. In an urban pediatric cohort study we tested whether wearing an air monitor impacted activity time based on continuous watch-based accelerometry. The majority (71%) reported that activity while wearing the monitor mimicked normal activity. Correspondingly, variation in activity while wearing versus not wearing the monitor did not differ greatly from baseline variation in activity (P = 0.84).

Does a Classroom Standing Desk Intervention Modify Standing and Sitting Behaviour and Musculoskeletal Symptoms during School Time and Physical Activity during Waking Time?

Children are increasingly spending more time sedentary at school and during leisure time. This study examined the effects of a standing desk intervention in a classroom on children's standing and sitting time at school, sedentary and physical activity levels throughout the day (waking hours), and musculoskeletal discomfort. A within-subjects crossover study design was used. Participants used either a standing desk or traditional seated desk for 21 days before swapping desks for another 21 days. Accelerometry and musculoskeletal discomfort data were collected during the last seven days of each 21-day period. Mixed models were used to analyse accelerometry data. Zero-inflated regression models and logistic regression models were used to analyse discomfort data. Forty-seven male students (aged 10⁻11 years) participated in the study. Standing time was 21 min/school day higher (p < 0.001) and sitting time was 24 min/school day lower (p = 0.003) when standing desks were used. No significant differences were found in sedentary and physical activity time during waking hours between the standing desk and seated desk conditions. Students were less likely to report musculoskeletal discomfort in the neck, shoulder, elbows and lower back when using standing desks (OR 0.52⁻0.74). Standing desks significantly increased classroom standing time and decreased musculoskeletal discomfort reports but had no overall effect on daily physical activity levels. Schools should consider moving towards classrooms enabling a variety of postures to potentially improve the long-term health of children.

Comparison of two methods to assess physical activity prevalence in children: an observational study using a nationally representative sample of Scottish children aged 10-11 years

OBJECTIVES

To describe the objectively measured levels of physical activity (PA) and sedentary time in a nationally representative sample of 10-11-year-old children, and compare adherence estimates to the UK PA guidelines using two approaches to assessing prevalence.

DESIGN

Nationally representative longitudinal cohort study.

SETTING

Scotland wide in partnership with the Growing up in Scotland (GUS) study. Data collection took place between May 2015 and May 2016.

PARTICIPANTS

The parents of 2402 GUS children were approached and 2162 consented to contact. Consenting children (n=1096) wore accelerometers for 8 consecutive days and 774 participants (427 girls, 357 boys) met inclusion criteria.

PRIMARY AND SECONDARY OUTCOME MEASURES

Total PA (counts per minute, cpm); time spent sedentary and in moderate-to-vigorous PA (MVPA); proportion of children with ≥60 min MVPA on each day of wear (daily approach); proportion of children with ≥60 min of MVPA on average across days of wear (average approach)-presented across boys and girls, index of multiple deprivation and season.

RESULTS

Mean PA level was 648 cpm (95% CI, 627 to 670). Children spent 7.5 hours (7.4-7.6) sedentary/day and 72.6 min (70.0-75.3) in MVPA/day. 11% (daily) and 68% (average) of children achieved the recommended levels of PA (P<0.05 for difference); a greater proportion of boys met the guidelines (12.5% vs 9.8%, NS; 75.9% vs 59.5%, P<0.001); guideline prevalence exhibited seasonal variation. No significant socioeconomic patterning existed across any outcome measure.

CONCLUSIONS

PA estimates are significantly influenced by the analytical method used to assess prevalence. This could have a substantial impact on the evaluation of interventions, policy objectives and public health investment. Existing guidelines, which focus on daily PA only may not further our understandings about the underlying construct itself. Gender differences exist within this age-group, suggesting greater investment, with particular consideration of seasonality, is needed for targeted intervention work in younger children.

Objectively measured sedentary behaviour and moderate and vigorous physical activity in different school subjects: a cross-sectional study

BACKGROUND

Evidence shows the positive influence of moderate and vigorous physical activity (MVPA) and negative influence of sedentary time on health and academic achievement. Although schools can significantly contribute to overall physical activity, little is known about MVPA and sedentary behaviour in different school subjects in different grades.

METHODS

Physical activity of 646 students from 18 schools (94 classes) and from three school stages (grades 1-9, aged 7-16) was measured with accelerometry for 5 school days. Time and proportion of MVPA and sedentary time, also average sedentary bout length was calculated for native language (Estonian), mathematics, science, foreign language, music and crafts lessons.

RESULTS

A total of 6363 lessons were measured, with lesson duration of 45 min. The average lesson time MVPA remained below 2.2 min in all school stages and in all subjects. Students in grades 4-6 had greatest decline in the proportion of lesson time MVPA in science (β = -1.9, 95%CI -3.1- -0.6) and music (-1.2, -2.1- -0.4) and in grades 7-9 in music (-1.7, -3.1- -0.3) lessons compared to grades 1-3. In grades 1-3 students spent on average 76% of lesson time (34.0 ± 7.0 min) as sedentary, whereas in grades 7-9 the average proportion of sedentary time was 87% (38.9 ± 5.7 min). An average sedentary bout length increased from 13 min in grades 1-3 to 20 min in grades 7-9. An increase in sedentary bout length from grades 1-3 compared to grades 7-9 was present in most subjects, except crafts, with smallest increase in foreign language (6 min, 3.5-8.9) and greatest in music lessons (16.6 min, 11.9-21.3). Lessons with prolonged sedentary bouts formed a maximum 36% of all lessons in grades 1-3 and 73% in grades 7-9.

CONCLUSION

The long sedentary time, bout length and low MVPA in most subjects were unfavourable in respect of both health and academic achievement. Significantly increasing sedentary time and sedentary bout length in older school stages highlights the need for interventions in all subjects and especially in older grades in order to combat the inactivity of children.