Levels and patterns of objectively-measured physical activity volume and intensity distribution in UK adolescents: the ROOTS study

Total and temporal patterning of physical activity in adolescents and associations with mental wellbeing

BACKGROUND

There is limited understanding of the extent to which differences in physical activity across the day and week may be associated with mental wellbeing. Such an understanding is needed for better targeting of interventions. In this study, we describe total and temporal patterning of physical activity across the week in adolescents (age 13-14y) and assess their prospective associations with mental wellbeing.

METHODS

1,983 13-14-year-old adolescent participants based in Cambridgeshire and Essex, recruited between 2016 and 2017 into the Get Others Active Trial provided data at baseline and 4 months. Physical activity was measured at baseline using wrist-worn accelerometers across different time segments (whole week, weekday schooltime, weekday out of school, and weekend), and operationalized as average movement-related acceleration for each time segment. Mental Wellbeing at baseline and 4 months was measured using the Warwick Edinburgh MentalWellbeing Scale. Associations between physical activity across different time segments (whole week, weekday schooltime, weekday out of school, and weekend) and mental wellbeing at 4 months were investigated using sex-stratified multi-level regression models, adjusted for covariates, and both adjusted and unadjusted for baseline mental wellbeing.

RESULTS

Our analyses found positive associations between physical activity and mental wellbeing at 4 months, unadjusted for baseline wellbeing. Among girls, positive associations were shown when considering physical activity across the whole week 0.07 (95% CI, 0.03-0.12), and across all separate time periods studied: weekday schooltime 0.07 (95% CI, 0.02-0.11), weekday out-of-school time 0.07 (95% CI, 0.03-0.12), and weekend 0.07 (95% CI, 0.02-0.11). For boys, similar associations were observed for activity across the week 0.07 (95% CI, 0.03-0.11), during weekday schooltime 0.08 (95% CI, 0.04-0.12), and weekday out-of-school time 0.07 (95% CI, 0.03-0.11), but not the weekend 0.01 (95% CI, -0.03-0.05). For both girls and boys, associations were attenuated below significance after adjusting for baseline wellbeing.

CONCLUSIONS

This longitudinal analysis showed positive associations between physical activity and later mental wellbeing in both male and female adolescents across most time segments. Higher physical activity throughout the week may be associated with better mental wellbeing in the adolescent population. Further research is required to understand determinants of change in wellbeing over time.

TRIAL REGISTRATION

Registration Number: ISRCTN31583496. Registered: 18/02/2014.

Shorter sleep among adolescents is associated with lower fruit and vegetable consumption the following day

BACKGROUND

Insufficient sleep has been associated with weight gain and metabolic dysregulation, with one suggested mechanism being through reduction in diet quality. Experimental evidence supports a causal effect of sleep timings on diet but this may not be applicable to a free-living adolescent population. In this analysis we use daily measures of sleep timings and diet quality, to examine the effect of sleep duration and timing on diet quality the following day among free-living adolescents.

METHODS

The ROOTS study is a prospective cohort recruited from secondary schools in Cambridgeshire and Suffolk (UK). Participants (n = 815) at mean age 15.0y (SD 0.3y) completed a diet diary and wore a combined heart rate and accelerometer device over 4 consecutive days. Sleep duration and timing (midpoint) were derived from acceleration and heart rate traces, while daily energy density and fruit and vegetable intake were calculated from dietary data. Analyses were performed at day-level (1815 person-days). Multilevel random effects models were used to test associations between sleep each night and subsequent day diet, with daily sleep and diet measures nested within individuals and schools, and adjusted for day-level and individual-level confounding variables.

RESULTS

Adolescents slept a mean of 7.88 hrs (SD 1.10) per night, reporting a mean energy density of 2.12 kcal/g (SD 0.48) and median energy-adjusted daily fruit and vegetable intake of 137.3 g (IQR 130.4). One hour shorter sleep duration was associated with lower intake of fruit and vegetables (-6.42 g, 95%CI -1.84, -10.99) the following day. An association with higher dietary energy density (0.016 kcal/g, 95%CI 0.034, -0.002) the following day was observed but did not reach statistical significance. Sleep timing was not associated with either fruit and vegetable intake (-2.52 g/d, 95%CI -7.66, 2.62) or dietary energy density (-0.001 kcal/g, 95%CI -0.022, 0.020).

CONCLUSIONS

Our observational findings from a free-living adolescent population support the experimental evidence for a causal role of sleep on diet, with shorter sleep duration at night leading to a small decrease in diet quality the following day. These findings support experimental evidence to suggest inclusion of sleep duration as one component of interventions designed to improve diet quality and weight status in adolescents.

Differences in physical activity between weekdays and weekend days among U.S. children and adults: Cross-sectional analysis of NHANES 2011–2014 data

This study investigates differences in physical activity between weekdays and weekend days, and its associations with sociodemographic and anthropometric characteristics in the U.S population using the NHANES 2011–2014 data. Physical activity was measured using ActiGraph GT3X+. Raw acceleration data were converted to Monitor-Independent Movement Summary units (MIMS-units) that account for inter-device variability and eliminates non-human movement. The daily MIMS-units were averaged for weekdays and weekend days. Demographic characteristics were self-reported. Height and weight were objectively measured. The sample included 6611 adults aged ≥ 20 years and 3520 children aged between 6 and 19 years. The results show that more MIMS-units were registered on weekdays compared to weekend days for adults (652, 95%CI = 533, 770) and children (889, 95%CI = 702, 1076). Factors associated with physical activity in adults (gender, age, marital status, ethnicity, education level, and weight status) were similar for weekdays and weekend days. In children, physical activity was associated with ethnicity, weight status, and age. The level of differences in physical activity between weekdays and weekend days among adults was larger for men, Hispanic Americans, and those with lower education levels. Differences among children were similar across subgroups, except for those aged 16–19 years who had smaller level of difference compared to those aged 12–15 years. In conclusion, adults and children were more active on weekdays than weekend days. The effects of structured days (i.e., weekdays) on physical activity appeared to be similar across most child subgroups but more heterogeneous for adult subgroups. Interventions increasing physical activity opportunities during weekend days are warranted.

Associations between socioeconomic position and young people's physical activity and sedentary behaviour in the UK: a scoping review

OBJECTIVE

To examine the evidence on the associations between socioeconomic position and young people's physical activity and sedentary behaviours in the UK.

DESIGN

Scoping review.

DATA SOURCES

PubMed, SCOPUS and Web of Science databases were searched for articles published up to and including January 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Observational studies in children and adolescents (aged 5-18 years) from the UK that had assessed associations between at least one indicator of socioeconomic position and at least one outcome of physical activity and/or sedentary behaviour.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by one reviewer and 20% were double checked. Indicators of socioeconomic position were tabulated with domains of physical activity and sedentary behaviour.

RESULTS

Fifty-seven publications were included in the review; 37 publications from 19 studies (k=23) of children and 21 publications from 15 studies (k=23) of adolescents. Most studies were cross-sectional. 63% of studies of children, and 40% of studies of adolescents assessed Index of Multiple Deprivation. Eighteen studies measured physical activity in children, 13 measured sedentary behaviour. Eleven studies of adolescents included a measure of physical activity, 10 included a measure of sedentary behaviour. Among children and adolescents, the association between socioeconomic position and measures of either physical activity or sedentary behaviour was highly variable depending on the measure of both socioeconomic position used and the behavioural outcome, with the exception of higher family affluence which was consistently associated with higher reported physical activity among adolescents.

CONCLUSION

Physical activity and sedentary behaviours of children and adolescents in the UK are complex and influenced by multiple indicators of socioeconomic position that are, in most cases, different across age stages, outcomes examined and measurement tools. Greater consistency in the use and measures of socioeconomic position as well as outcomes of behaviour are required for robust country-specific meta-analyses.

Adolescents' Behaviors, Fitness, and Knowledge Related to Active Living before and during the COVID-19 Pandemic: A Repeated Cross-Sectional Analysis

Background: Nearly all schools in the United States experienced shutdown followed by phased reopening during the COVID-19 pandemic, thereby limiting students’ opportunities for physical activity (PA). This study aimed to examine adolescents’ PA at school (PAS) and PA out-of-school (PAO), screen-based sedentary behaviors (SbSB), health-related fitness, and knowledge understanding about PA and fitness before and during the pandemic. Methods: Three rounds of data were collected: Time 1 pre-pandemic (January 2020; n = 405), Time 2 schools partially reopened (February 2021; n = 412), and Time 3 schools fully reopened (March 2021; n = 450). Adolescents completed the Youth Activity Profile, the 20 m Progressive Aerobic Cardiovascular Endurance Run (PACER) test and Plank test, and a written test, to measure the behaviors (T1, T2, T3), fitness (T2–T3), and knowledge (T1, T2, T3), respectively. Results: Inferential statistical analyses revealed a significant time effect for the behaviors and fitness. From T1 to T2 PAO decreased but PAS increased; whereas SbSB decreased at T3 compared to T1 and T2. Health-related fitness improved from T2 to T3. Further, the change patterns for SbSB varied by grade, and those for knowledge understanding varied by gender. Conclusion: The findings confirm the disruptive impact of the COVID-19 pandemic on adolescents’ active living but varied by school grade and gender. The favorable changes from T2 to T3 observed for fitness and other constructs may be partially attributable to an interrupted fitness education intervention. The findings may guide the design and evaluation of future interventions addressing the physical inactivity pandemic during public health crises (e.g., COVID-19).

An online family-based self-monitoring and goal-setting intervention to improve children’s physical activity: the FRESH feasibility trial and three-arm pilot RCT

Background

Family-based physical activity promotion presents a promising avenue for promoting whole-family physical activity, but high-quality research is lacking.

Objectives

To assess the feasibility, acceptability and preliminary effectiveness of FRESH (Families Reporting Every Step to Health), a child-led online family-based physical activity intervention; and to identify effective and resource-efficient family recruitment strategies.

Design

The project consisted of (1) a randomised feasibility trial, (2) a randomised controlled pilot trial and (3) a systematic review and Delphi study.

Setting

Norfolk/Suffolk counties, UK.

Participants

Families, recruited from schools, workplaces and community settings, were eligible to participate if one child aged 7–11 years and one adult responsible for their care provided written consent; all family members could participate.

Interventions

The FRESH intervention, guided by self-determination theory, targeted whole families and was delivered via an online platform. All family members received pedometers and were given website access to select family step challenges to ‘travel’ to target cities around the world, log steps, and track progress as they virtually globetrotted. Families were randomised to FRESH intervention, pedometer-only or control arm.

Main outcome measures

Physical (e.g. blood pressure), psychosocial (e.g. family functioning) and behavioural (e.g. device-measured family physical activity) measures were collected at baseline and at 8- and 52-week follow-up. A mixed-methods process evaluation assessed the acceptability of the intervention and evaluation.

Data sources review

Systematic search of four databases (Cochrane Library, PubMed, PsycINFO and SCOPUS).

Review methods

Articles were screened in duplicate, and data extraction was fully checked. Academic experts participated in the three-round Delphi study. Data were combined to identify effective and resource-efficient family recruitment strategies.

Inclusion criteria

Included generally healthy school-aged children and at least one adult; intervention attempted to change physical activity, sedentary behaviour, screen use, diet, or prevent overweight/obesity in multiple family members; presented relevant measure of effect in children and adults.

Results

The feasibility study (12 families, 32 participants; 100% retention at 8 weeks) demonstrated the feasibility and acceptability of FRESH, but highlighted that adaptations were required. Of 41 families recruited in the pilot study (149 participants), 98% and 88% were retained at the 8-week and 52-week follow-up, respectively. More children in the FRESH arm self-reported doing more family physical activity, and they thought that FRESH was fun. There were no notable between-group differences in children’s outcomes. Change in moderate to vigorous physical activity at 8 weeks favoured FRESH intervention adults [vs. control: 9.4 minutes/week (95% confidence interval 0.4 to 18.4) vs. pedometer only: 15.3 (95% confidence interval 6.0 to 24.5)], and was stronger in fathers, but this was not maintained. In 49 included studies, apart from recruitment settings and strategies used (reported in 84% and 73% of the studies, respectively), recruitment details were scarce. School-based recruitment was predominant. The Delphi study identified a wide range of recruitment settings and strategies.

Limitations

Recruitment was the main limitation of the FRESH studies; generalisability of the proposed recruitment strategies may be limited.

Conclusions

This study has demonstrated the feasibility and acceptability of the FRESH intervention. However, we failed to recruit the target sample size and were unable to demonstrate a signal of effectiveness. Future research should employ a multifaceted recruitment approach.

Future work

Further refinements to intervention delivery and recruitment methods should be investigated.

Study registration

Current Controlled Trials ISRCTN12789422 and PROSPERO CRD42019140042.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 9. See the NIHR Journals Library website for further project information.

Are all MVPA minutes equal? Associations between MVPA characteristics, independent of duration, and childhood adiposity

BACKGROUND

The inverse relationship between moderate-to-vigorous physical activity (MVPA) duration and childhood adiposity is well established. Less is known about how characteristics of MVPA accumulation may be associated with adiposity, independent of MVPA duration. This study aimed to investigate how the MVPA characteristics of children, other than duration (bout length, time of day, day-to-day consistency, intensity), were associated with adiposity.

METHODS

Cross-sectional study of the Australian arm of the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) (participants: n = 424, age range 9-11, 44% male). Adiposity was determined by percent body fat via bioelectrical impedance. MVPA duration and characteristics (bout length, time of day, consistency, intensity) were derived from 7-day, 24-h accelerometry. Generalised estimating equations were used to examine the individual and multivariate associations between MVPA characteristics and adiposity.

RESULTS

Univariate analyses showed that higher MVPA duration (β range = - 0.26,-0.15), longer bouts of MVPA (β range = 0.15,0.22) and higher MVPA intensity (β range = - 0.20,-0.13) were all inversely associated with adiposity (all p < 0.05). When models were adjusted for MVPA duration, only MVPA intensity (β range = - 0.16,-0.04) showed consistent significant associations with adiposity.

CONCLUSIONS

Characteristics of MVPA other than duration and intensity appear to be unrelated to adiposity.

Impact of The Daily Mile on children's physical and mental health, and educational attainment in primary schools: iMprOVE cohort study protocol

INTRODUCTION

School-based active mile initiatives such as The Daily Mile (TDM) are widely promoted to address shortfalls in meeting physical activity recommendations. The iMprOVE Study aims to examine the impact of TDM on children's physical and mental health and educational attainment throughout primary school. METHODS AND ANALYSIS: iMprOVE is a longitudinal quasi-experimental cohort study. We will send a survey to all state-funded primary schools in Greater London to identify participation in TDM. The survey responses will be used for non-random allocation to either the intervention group (Daily Mile schools) or to the control group (non-Daily Mile schools). We aim to recruit 3533 year 1 children (aged 5-6 years) from 77 primary schools and follow them up annually until the end of their primary school years. Data collection taking place at baseline (children in school year 1) and each primary school year thereafter includes device-based measures of moderate-to-vigorous physical activity (MVPA) and questionnaires to measure mental health (Strengths and Difficulties Questionnaire) and educational attainment (ratings from 'below expected' to 'above expected levels'). The primary outcome is the mean change in MVPA minutes from baseline to year 6 during the school day among the intervention group compared with controls. We will use multilevel linear regression models adjusting for sociodemographic data and participation in TDM. The study is powered to detect a 10% (5.5 min) difference between the intervention and control group which would be considered clinically significant.

ETHICS AND DISSEMINATION

Ethics has been approved from Imperial College Research Ethics Committee, reference 20IC6127. Key findings will be disseminated to the public through research networks, social, print and media broadcasts, community engagement opportunities and schools. We will work with policy-makers for direct application and impact of our findings.

A school-based, peer-led programme to increase physical activity among 13- to 14-year-old adolescents: the GoActive cluster RCT

Background

Adolescent physical activity levels are low and are associated with rising disease risk and social disadvantage. The Get Others Active (GoActive) intervention was co-designed with adolescents and teachers to increase physical activity in adolescents.

Objective

To assess the effectiveness and cost-effectiveness of the school-based GoActive programme in increasing adolescents’ moderate-to-vigorous physical activity.

Design

A cluster randomised controlled trial with an embedded mixed-methods process evaluation.

Setting

Non-fee-paying schools in Cambridgeshire and Essex, UK (n = 16). Schools were computer randomised and stratified by socioeconomic position and county.

Participants

A total of 2862 Year 9 students (aged 13–14 years; 84% of eligible students).

Intervention

The iteratively developed feasibility-tested refined 12-week intervention trained older adolescents (mentors) and in-class peer leaders to encourage classes to undertake two new weekly activities. Mentors met with classes weekly. Students and classes gained points and rewards for activity in and out of school.

Main outcome measures

The primary outcome was average daily minutes of accelerometer-assessed moderate-to-vigorous physical activity at 10 months post intervention. Secondary outcomes included accelerometer-assessed activity during school, after school and at weekends; self-reported physical activity and psychosocial outcomes; cost-effectiveness; well-being and a mixed-methods process evaluation. Measurement staff were blinded to allocation.

Results

Of 2862 recruited participants, 2167 (76%) attended 10-month follow-up measurements and we analysed the primary outcome for 1874 (65.5%) participants. At 10 months, there was a mean decrease in moderate-to-vigorous physical activity of 8.3 (standard deviation 19.3) minutes in control participants and 10.4 (standard deviation 22.7) minutes in intervention participants (baseline-adjusted difference –1.91 minutes, 95% confidence interval –5.53 to 1.70 minutes; p = 0.316). The programme cost £13 per student compared with control. Therefore, it was not cost-effective. Non-significant indications of differential impacts suggested detrimental effects among boys (boys –3.44, 95% confidence interval –7.42 to 0.54; girls –0.20, 95% confidence interval –3.56 to 3.16), but favoured adolescents from lower socioeconomic backgrounds (medium/low 4.25, 95% confidence interval –0.66 to 9.16; high –2.72, 95% confidence interval –6.33 to 0.89). Mediation analysis did not support the use of any included intervention components to increase physical activity. Some may have potential for improving well-being. Students, teachers and mentors mostly reported enjoying the GoActive intervention (56%, 87% and 50%, respectively), but struggled to conceptualise their roles. Facilitators of implementation included school support, embedding a routine, and mentor and tutor support. Challenges to implementation included having limited school space for activities, time, and uncertainty of teacher and mentor roles.

Limitations

Retention on the primary outcome at 10-month follow-up was low (65.5%), but we achieved our intended sample size, with retention comparable to similar trials.

Conclusions

A rigorously developed school-based intervention (i.e. GoActive) was not effective in countering the age-related decline in adolescent physical activity. Overall, this mixed-methods evaluation provides transferable insights for future intervention development, implementation and evaluation.

Future work

Interdisciplinary research is required to understand educational setting-specific implementation challenges. School leaders and authorities should be realistic about expectations of the effect of school-based physical activity promotion strategies implemented at scale.

Trial registration

Current Controlled Trials ISRCTN31583496.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 6. See the NIHR Journals Library website for further project information. This work was additionally supported by the Medical Research Council (London, UK) (Unit Programme number MC_UU_12015/7) and undertaken under the auspices of the Centre for Diet and Activity Research (Cambridge, UK), a UK Clinical Research Collaboration Public Health Research Centre of Excellence. Funding from the British Heart Foundation (London, UK), Cancer Research UK (London, UK), Economic and Social Research Council (Swindon, UK), Medical Research Council, the National Institute for Health Research (Southampton, UK) and the Wellcome Trust (London, UK), under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged (087636/Z/08/Z; ES/G007462/1; MR/K023187/1). GoActive facilitator costs were borne by Essex and Cambridgeshire County Councils.

Isotemporal Substitution of Time Between Sleep and Physical Activity: Associations With Cardiovascular Risk Factors in Early Rheumatoid Arthritis

OBJECTIVE

We aimed to determine relationships between objectively measured nightly sleep, sedentary behavior (SB), light physical activity (LPA), and moderate to vigorous physical activity (MVPA) with risk factors for cardiovascular disease (CVD) in patients with early rheumatoid arthritis (RA). Furthermore, we aimed to estimate consequences for these risk factors of theoretical displacements of 30 minutes per day in one behavior with the same duration of time in another.

METHODS

This cross-sectional study included 78 patients with early RA. Nightly sleep, SB, LPA, and MVPA were assessed by a combined heart rate and accelerometer monitor. Associations with risk factors for CVD were analyzed using linear regression models and consequences of reallocating time between the behaviors by isotemporal substitution modeling.

RESULTS

Median (Q1-Q3) nightly sleep duration was 4.6 (3.6-5.8) hours. Adjusted for monitor wear time, age, and sex, 30-minutes-longer sleep duration was associated with favorable changes in the values β (95% confidence interval [CI]) for waist circumference by -2.2 (-3.5, -0.9) cm, body mass index (BMI) by -0.9 (-1.4, -0.4) kg/m2 , body fat by -1.5 (-2.3, -0.8)%, fat-free mass by 1.6 (0.8, 2.3)%, sleeping heart rate by -0.8 (-1.5, -0.1) beats per minute, and systolic blood pressure by -2.5 (-4.0, -1.0) mm Hg. Thirty-minute decreases in SB, LPA, or MVPA replaced with increased sleep was associated with decreased android fat and lower systolic blood pressure levels. Replacement of SB or LPA with MVPA yielded lower BMIs.

CONCLUSION

Shorter sleep during the night is common among patients with early RA and is associated with adverse risk factors for CVD.

Meeting the Physical Activity Recommendations and Its Relationship with Obesity-Related Parameters, Physical Fitness, Screen Time, and Mediterranean Diet in Schoolchildren

The up-to-date scientific evidence suggests that adequate levels of physical activity provide essential health benefits for children and adolescents and help to maintain a healthy body weight. In this sense, children and adolescents should at least accumulate 60 min of moderate-to-vigorous physical activity in a daily basis to achieve these benefits and be considered active. Likewise, some lifestyle-related elements may interact with each other in an antagonistic or synergistic way to modify physical activity status. Thus, a better understanding of how meeting physical activity recommendations influences these potentially modifiable lifestyle factors (obesity-related parameters, physical fitness, dietary habits, or sedentary behaviour) would significantly reinforce the importance of complying with those recommendations from a health perspective and support the establishment of strategies for the promotion of diminishing the lower trends of physical activity among the young population. This study seeks to verify the association of meeting physical activity international recommendations with obesity-related parameters, global physical fitness, screen time, and Mediterranean diet in Spanish schoolchildren aged 8 to 13. A cross-sectional study was performed including 250 schoolchildren (41.2% girls) aged 8-13 (9.7 ± 1.2) from six primary schools in the Region of Murcia (Spain). Results: A higher proportion of children who complying with physical activity recommendations shows normal weight, no abdominal obesity, and low adiposity in comparison to other with different obesity-related parameters categories. Higher values in global physical fitness score were found in those who meet the physical activity international recommendations in both sexes. These higher values were also shown for adherence to the Mediterranean diet in both sexes; not being so in the case of screen time. Notwithstanding, none of these mean differences were statistically significant. To conclude, the proportion of schoolchildren meeting the physical activity recommendations in our study is low. A higher proportion of children who meet with physical activity recommendations present normal weight, no abdominal obesity and low adiposity in comparison to other obesity-related parameters categories in both sexes. Likewise, those considered as active children seem to have higher global physical fitness score and adherence to the Mediterranean diet than children who do not meet the recommendations.

The Gender Difference in Association between Home-Based Environment and Different Physical Behaviors of Chinese Adolescents

Purpose: The aim of this study was to evaluate the home-based physical activity (PA) environmental characteristics, and different types of physical behavior level of adolescents in different genders, and explore the impact of different domains of home-based PA environmental factors on different physical behaviors of adolescents in different genders. Methods: Five hundred forty-four adolescents aged from 12 to 18 years old (males: n = 358, females: n = 186) and their parents were analyzed in this cross-sectional survey. The volume of various physical behaviors of all adolescent subjects were measured by the ActiGraph wGT3X-BT accelerometer, and the level in different domains of home-based environmental characteristics were assessed by the Gattshall’s home-based PA environment questionnaire, which was answered by adolescents’ parents. The difference in the volume of different physical behaviors was examined using Kruskal–Wallis analysis. The difference in home physical environment and home social environment for adolescents was examined using one-way analysis of variance (ANOVA). Multiple linear regression analysis in the adjusted model was used to evaluate the influence of different home-based PA environmental domains (PA availability, PA accessibility, Parental role-modeling of PA, and Parental policies around PA) on different physical behaviors (sedentary behavior, SB; light-intensity physical activity, LPA; and moderate-vigorous physical activity, MVPA) of adolescents (boys and girls). Results: The volume of LPA and MVPA, the score of PA accessibility in the home physical environment, and the score of home social environment of boys are significantly higher than those of girls, while the SB volume of boys is significantly lower than that of girls. The PA availability, the parents’ role-modeling of PA in same-sex parent–child dyads, and the parents’ policies around PA in opposite-sex parent–child dyads are significantly associated with adolescents’ decreased SB and increased LPA and MVPA. Conclusion: There is significant gender difference in adolescents’ physical behaviors and home-based environmental characteristics, as well as in the association between adolescents’ physical behaviors and their home-based environment. The PA availability, the parents’ role-modeling of PA in same-sex parent–child dyads, and the parents’ policies around PA in opposite-sex parent–child dyads can significantly promote adolescents’ healthy physical behaviors.

A whole family-based physical activity promotion intervention: findings from the families reporting every step to health (FRESH) pilot randomised controlled trial

Introduction

This study assessed the feasibility and acceptability of FRESH (Families Reporting Every Step to Health), a theory-based child-led family physical activity (PA) intervention delivered online. We also assessed the preliminary effectiveness of the intervention on outcomes of interest and whether pre-specified criteria were met to progress to a full-scale definitive trial.

Methods

In a three-armed randomised pilot trial, 41 families (with a 7–11-year-old index child) were allocated to a: ‘family’ (FAM), ‘pedometer-only’ (PED), or a no-treatment control (CON) arm. The FAM arm received access to the FRESH website, allowing participants to select step challenges to ‘travel’ to target cities around the world, log their steps, and track progress as families virtually globetrot. FAM and PED arms also received family sets of pedometers. All family members could participate in the evaluation. Physical (e.g., fitness, blood pressure), psychosocial (e.g., social support), behavioural (e.g., objectively-measured PA), and economic (e.g., expenditure for PA) data were collected at baseline, 8- and 52-weeks.

Results

At 8- and 52-weeks, 98 and 88% of families were retained, respectively. Most children liked participating in the study (> 90%) and thought it was fun (> 80%). Compared to the PED (45%) and CON (39%) arms, a higher percentage of children in the FAM (81%) arm reported doing more activities with their family. Adults agreed that FRESH encouraged their family do more PA and made their family more aware of the amount of PA they do. No notable between-group differences were found for childrens’ minutes in moderate-to-vigorous PA. Sizeable changes of 9.4 (95%CI: 0.4, 18.4) and 15.3 (95%CI: 6.0, 24.5) minutes in moderate-to-vigorous PA was found for adults in the FAM group compared to those in the PED or CON groups, respectively. No other notable differences were found.

Conclusion

This study demonstrates feasibility and acceptability of the FRESH intervention. All progression criteria were at least partially satisfied. However, we failed to recruit the target sample size and did not find a signal of effectiveness on PA particularly long-term or in children. Further refinements are required to progress to a full-scale trial.

Trial registration

This study was prospectively registered (ISRCTN12789422) on 16/03/2016.

Prevalence of accelerometer-measured physical activity in adolescents in Fit Futures - part of the Tromsø Study

BACKGROUND

Previous studies show large variations in physical activity (PA) levels among adolescents. However, the number of studies is limited and even fewer studies have assessed PA in adolescents by accelerometer devices. This study aimed to describe accelerometer-measured PA levels in adolescents in a population-based cohort in Northern Norway.

METHODS

In 611 students aged 16-17 years attending the Fit Futures Study, PA was measured by Actigraph GT3X for seven consecutive days. PA was expressed as total PA volume (counts per minute, CPM), time spent in intensity zones, steps per day, and fulfilment of WHO recommendation (i.e. accumulation of 60 min or more of at least moderate intensity PA per day). Potential correlates of PA such as sex, socioeconomic status, study program, self-perceived health, and PA variations by weekday versus weekend were also examined.

RESULTS

16% of the girls and 25% of the boys fulfilled current WHO-recommendations. Total PA volume (CPM) was higher in boys than in girls (353 (SD 130) versus 326 (SD 114) CPM, p < 0.05). PA levels differed with study program and increased with better self-perceived health, but were not associated with socioeconomic status. Both boys and girls were more active on weekdays than weekends (altogether; 350 (SD 124) versus 299 (SD 178) CPM, p < 0.05).

CONCLUSIONS

In this cohort of adolescents, less than 25% of 16-17-year-old boys and girls fulfilled the WHO recommendations. The levels of physical activity in 16-17-year-old adolescents are similar to previous data reported in adults.

Effectiveness and cost-effectiveness of the GoActive intervention to increase physical activity among UK adolescents: A cluster randomised controlled trial

BACKGROUND

Less than 20% of adolescents globally meet recommended levels of physical activity, and not meeting these recommended levels is associated with social disadvantage and rising disease risk. The determinants of physical activity in adolescents are multilevel and poorly understood, but the school's social environment likely plays an important role. We conducted a cluster randomised controlled trial to assess the effectiveness of a school-based programme (GoActive) to increase moderate-to-vigorous physical activity (MVPA) among adolescents.

METHODS AND FINDINGS

Non-fee-paying, co-educational schools including Year 9 students in the UK counties of Cambridgeshire and Essex were eligible for inclusion. Within participating schools (n = 16), all Year 9 students were eligible and invited to participate. Participants were 2,862 13- to 14-year-olds (84% of eligible students). After baseline assessment, schools were computer-randomised, stratified by school-level pupil premium funding (below/above county-specific median) and county (control: 8 schools, 1,319 participants, mean [SD] participants per school n = 165 [62]; intervention: 8 schools, 1,543 participants, n = 193 [43]). Measurement staff were blinded to allocation. The iteratively developed, feasibility-tested 12-week intervention, aligned with self-determination theory, trained older adolescent mentors and in-class peer-leaders to encourage classes to conduct 2 new weekly activities. Students and classes gained points and rewards for engaging in any activity in or out of school. The primary outcome was average daily minutes of accelerometer-assessed MVPA at 10-month follow-up; a mixed-methods process evaluation evaluated implementation. Of 2,862 recruited participants (52.1% male), 2,167 (76%) attended 10-month follow-up measurements; we analysed the primary outcome for 1,874 participants (65.5%). At 10 months, there was a mean (SD) decrease in MVPA of 8.3 (19.3) minutes in the control group and 10.4 (22.7) minutes in the intervention group (baseline-adjusted difference [95% confidence interval] -1.91 minutes [-5.53 to 1.70], p = 0.316). The programme cost £13 per student compared with control; it was not cost-effective. Overall, 62.9% of students and 87.3% of mentors reported that GoActive was fun. Teachers and mentors commented that their roles in programme delivery were unclear. Implementation fidelity was low. The main methodological limitation of this study was the relatively affluent and ethnically homogeneous sample.

CONCLUSIONS

In this study, we observed that a rigorously developed school-based intervention was no more effective than standard school practice at preventing declines in adolescent physical activity. Interdisciplinary research is required to understand educational-setting-specific implementation challenges. School leaders and authorities should be realistic about expectations of the effect of school-based physical activity promotion strategies implemented at scale.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN31583496.

Descriptive epidemiology of energy expenditure in the UK: findings from the National Diet and Nutrition Survey 2008-15

Background

Little is known about population levels of energy expenditure, as national surveillance systems typically employ only crude measures. The National Diet and Nutrition Survey (NDNS) in the UK measured energy expenditure in a 10% subsample by gold-standard doubly labelled water (DLW).

Methods

DLW-subsample participants from the NDNS (383 males, 387 females) aged 4–91 years were recruited between 2008 and 2015 (rolling programme). Height and weight were measured and body-fat percentage estimated by deuterium dilution.

Results

Absolute total energy expenditure (TEE) increased steadily throughout childhood, ranging from 6.2 and 7.2 MJ/day in 4- to 7-year-olds to 9.7 and 11.7 MJ/day for 14- to 16-year-old girls and boys, respectively. TEE peaked in 17- to 27-year-old women (10.7 MJ/day) and 28- to 43-year-old men (14.4 MJ/day), before decreasing gradually in old age. Physical-activity energy expenditure (PAEE) declined steadily with age from childhood (87 kJ/day/kg in 4- to 7-year-olds) through to old age (38 kJ/day/kg in 71- to 91-year-olds). No differences were observed by time, region and macronutrient composition. Body-fat percentage was strongly inversely associated with PAEE throughout life, irrespective of expressing PAEE relative to body mass or fat-free mass. Compared with females with <30% body fat, females with >40% recorded 29 kJ/day/kg body mass and 18 kJ/day/kg fat-free mass less PAEE in analyses adjusted for age, geographical region and time of assessment. Similarly, compared with males with <25% body fat, males with >35% recorded 26 kJ/day/kg body mass and 10 kJ/day/kg fat-free mass less PAEE.

Conclusions

This first nationally representative study reports levels of human-energy expenditure as measured by gold-standard methodology; values may serve as a reference for other population studies. Age, sex and body composition are the main determinants of energy expenditure.

Key Messages

This is the first nationally representative study of human energy expenditure, covering the UK in the period 2008-2015.

Total energy expenditure (MJ/day) increases steadily with age throughout childhood and adolescence, peaks in the 3^rd decade of life in women and 4^th decade of life in men, before decreasing gradually in old age.

Physical activity energy expenditure (kJ/day/kg or kJ/day/kg fat-free mass) declines steadily with age from childhood to old age, more steeply so in males.

Body-fat percentage is strongly inversely associated with physical activity energy expenditure.

We found little evidence that energy expenditure varied by geographical region, over time, or by dietary macronutrient composition.

Web-based intervention on the promotion of physical activity among Iranian youth using the transtheoretical model

BACKGROUND

Sedentary habits may increase the noncommunicable disease risk factors, and few teens get enough physical activity. Therefore, the current study aimed to examine the effects of a web-based intervention on the promotion of physical activity among adolescents using the transtheoretical model (TTM).

METHODS AND MATERIALS

A quasi-experimental study was conducted on 278 high school students who were randomly allocated into one of the three groups: two web-based intervention groups. The intervention groups 1 and 2 received education through web (www.salamat.family), but the second group received educational strategies based on TTM. Five questionnaires were applied two times before the intervention and 6 months after the intervention. And, in the control group, the data were collected using stage of exercise behavior change questionnaire and the International Physical Activity Questionnaire. Student's t-test and two-way analysis of variance, and McNemar's test were applied to compare before and after the intervention. P < 0.05 was considered statistically significant.

RESULTS

The mean differences for TTM constructs related to exercise behaviors (processes of change, self-efficacy, and decisional balance) in intervention groups 1 and 2 were very higher than the control group. Participants in intervention groups 1 and 2 who had low or moderate physical activity before the intervention were placed in high physical activity after it.

CONCLUSION

According to the obtained results, education on PA based on website effective, but if we use education based on TTM, it will be more useful on the behavior.

Associations Between Parent Self-Reported and Accelerometer-Measured Physical Activity and Sedentary Time in Children: Ecological Momentary Assessment Study

BACKGROUND

Retrospective self-report questionnaires are the most common method for assessing physical activity (PA) and sedentary behavior (SB) in children when the use of objective assessment methods (eg, accelerometry) is cost prohibitive. However, self-report measures have limitations (eg, recall bias). The use of real-time, mobile ecological momentary assessment (EMA) has been proposed to address these shortcomings. The study findings will provide useful information for researchers interested in using EMA surveys for measuring PA and SB in children, particularly when reported by a parent or caregiver.

OBJECTIVE

This study aimed to examine the associations between the parent's EMA report of their child's PA and SB and accelerometer-measured sedentary time (ST), light-intensity PA (LPA), and moderate-to-vigorous-intensity PA (MVPA) and to examine if these associations differed by day of week, sex, and season.

METHODS

A total of 140 parent-child dyads (mean child age 6.4 years, SD 0.8; n=66 girls; n=21 African American; n=24 American Indian; n=25 Hispanic/Latino; n=24 Hmong; n=22 Somali; and n=24 white) participated in this study. During an 8-day period, parents reported child PA and SB via multiple daily signal contingent EMA surveys, and children wore a hip-mounted accelerometer to objectively measure ST, LPA, and MVPA. Accelerometer data was matched to the time period occurring before parent EMA-report of child PA and SB. Generalized estimating equations with interaction-term analyses were performed to determine whether the relationship between parent-EMA report of child PA and SB and accelerometer-measured ST and LPA and MVPA outcomes differed by day of the week, sex and season.

RESULTS

The parent's EMA report of their child's PA and SB was strongly associated with accelerometer-measured ST, LPA, and MVPA. The parent's EMA report of their child's PA was stronger during the weekend than on weekdays for accelerometer-measured ST (P≤.001) and LPA (P<.001). For the parent's EMA report of their child's SB, strong associations were observed with accelerometer-measured ST (P<.001), LPA (P=.005), and MVPA (P=.008). The findings related to sex-interaction terms indicated that the association between the parent-reported child's PA via EMA and the accelerometer-measured MVPA was stronger for boys than girls (P=.02). The association between the parent's EMA report of their child's PA and SB and accelerometer-measured ST and PA was similar across seasons in this sample (all P values >.31).

CONCLUSIONS

When the use of accelerometry-based methods is not feasible and in contexts where the parent is able to spend more proximate time observing the child's PA and SB, the parent's EMA report might be a superior method for measuring PA and SB in young children relative to self-report, given the EMA's strong associations with accelerometer-measured PA and ST.

Objectively-measured sedentary time and physical activity in a bi-ethnic sample of young children: variation by socio-demographic, temporal and perinatal factors

Background

Evidence suggests that South Asian school-aged children and adults are less active compared to the white British population. It is unknown if this generalises to young children. We aimed to describe variability in levels of physical activity and sedentary time in a bi-ethnic sample of young children from a deprived location.

Methods

This observational study included 202 South Asian and 140 white British children aged 1.5 to 5y, who provided 3181 valid days of triaxial accelerometry (Actigraph GT3X+). Variability in sedentary time and physical activity levels were analysed by linear multilevel modelling. Logistic multilevel regression was used to identify factors associated with physical inactivity (failing to perform ≥180 min of total physical activity including ≥60 min moderate-to-vigorous physical activity (MVPA) per day).

Results

There were no significant ethnic differences in the overall levels of behaviours; South Asian and white British children spent half of daily time sedentary, just over 40% in light physical activity, and the remaining 7.5 to 8% of time in MVPA. Sedentary time was lower and physical activity levels were higher in older children, and levels of MVPA and vector magnitude counts per minute (CPM) were higher on weekends compared to weekdays. In South Asian children, sedentary time was lower on weekends. Sedentary time was lower and physical activity levels were higher in spring compared to winter in white British children, and in all seasons compared to winter in South Asian children. South Asian children born at high birth weight performed more MVPA, and in both ethnicities there was some evidence that children with older mothers were more sedentary and less active. Sedentary time was higher and light physical activity was lower in South Asian children in the highest compared to the lowest income families. South Asian girls performed less MVPA, registered fewer vector magnitude CPM, and were 3.5 times more likely to be physically inactive than South Asian boys.

Conclusions

Sedentary time and physical activity levels vary by socio-demographic, temporal and perinatal characteristics in young children from a deprived location. South Asian girls have the most to gain from efforts to increase physical activity levels.

Trial registration

The Pre-schoolers in the Playground (PiP) pilot randomized controlled trial is registered with the ISRCTN (ISRCTN54165860; http://www.isrctn.com).

Intensity and frequency of physical activity and high blood pressure in adolescents: A longitudinal study

Despite limited evidence on the association between physical activity (PA) and blood pressure (BP) in youth, experts recommend that adolescents engage regularly in moderate-to-vigorous PA. We examined the relationships between PA intensity and frequency and the likelihood of having high BP in a population-based cohort of adolescents from Montréal, Canada. PA was self-reported every 3 months from grade 7 to 11, and BP was measured at ages 12.8, 15.2, and 17.0 years on average. We analyzed data from 993 participants (mean [SD] age = 16.0 [1.0], 51.6% female) with BP data at ages 15.2 and/or 17.0 years, using pooled ordinal logistic regression. BP (normal/elevated/hypertensive range) was the outcome, and past-year PA intensity and frequency were potential predictors. Eight percent of participants had elevated BP (120-129/<80), and 3.2% had BP in the hypertensive range (≥130/≥80). Participants engaged in a median (interquartile range) of 7.0 (4.5, 9.3) and 5.5 (2, 10.8) moderate and vigorous PA sessions/week, respectively. After adjusting for age, sex, mother's education, use of alcohol and cigarette consumption, engaging in PA more intense than light during the previous year was associated with a lower odds of having BP in the hypertensive range (ORs [95% CIs] = 0.93 [0.88, 0.97] to 0.97 [0.94, 0.99]). The relationships were not altered by adjusting for BMI. Our findings support recommendations that adolescents engage in at least moderate PA on a regular basis to prevent development of BP in the hypertensive range.

Associations between adolescents' preference for fitness activities and achieving the recommended weekly level of physical activity

This study aimed to explore differences in rates of achieving the weekly physical activity (PA) recommendation between adolescents who preferred fitness PA and those who did not. Furthermore, we investigated the types of PA practiced by adolescents. In total, 9513 participants from the Czech Republic and Poland, aged 15-18 years took part in the study between 2009 and 2016. Out of this source sample, 4977 self-reported their weekly PA using the IPAQ-Long Form, and 1348 objectively monitored their weekly PA using pedometers and recorded the type of PA. Boys ranked fitness PA third, after team and individual sports. For girls, the preference for fitness PA grew at the expense of dance and outdoor PA. Among Czech and Polish boys as well as Czech girls, those who preferred fitness PA were more likely to achieve the recommended weekly PA level than those who did not prefer fitness PA. We did not find a significant difference in other types of PA and rates of achieving the recommendation of 11,000 steps/day. Preference for fitness PA was associated with an increased likelihood (OR = 1.30; 95% CI = 1.12-1.52; p < 0.001) of achieving the recommendation for PA. When promoting adolescents' PA, it is necessary to consider preferred PA types. The PA recommendation was met by almost 33% of adolescents who indicated a preference for fitness PA, but only by 22% of those not preferring fitness activities. Organized PA is also important for meeting PA recommendations.

Descriptive epidemiology of physical activity energy expenditure in UK adults (The Fenland study)

BACKGROUND

Physical activity (PA) plays a role in the prevention of a range of diseases including obesity and cardiometabolic disorders. Large population-based descriptive studies of PA, incorporating precise measurement, are needed to understand the relative burden of insufficient PA levels and to inform the tailoring of interventions. Combined heart and movement sensing enables the study of physical activity energy expenditure (PAEE) and intensity distribution. We aimed to describe the sociodemographic correlates of PAEE and moderate-to-vigorous physical activity (MVPA) in UK adults.

METHODS

The Fenland study is a population-based cohort study of 12,435 adults aged 29-64 years-old in Cambridgeshire, UK. Following individual calibration (treadmill), participants wore a combined heart rate and movement sensor continuously for 6 days in free-living, from which we derived PAEE (kJ•day- 1•kg- 1) and time in MVPA (> 3 & > 4 METs) in bouts greater than 1 min and 10 min. Socio-demographic information was self-reported. Stratum-specific summary statistics and multivariable analyses were performed.

RESULTS

Women accumulated a mean (sd) 50(20) kJ•day- 1•kg- 1 of PAEE, and 83(67) and 33(39) minutes•day- 1 of 1-min bouted and 10-min bouted MVPA respectively. By contrast, men recorded 59(23) kJ•day- 1•kg- 1, 124(84) and 60(58) minutes•day- 1. Age and BMI were also important correlates of PA. Association with age was inverse in both sexes, more strongly so for PAEE than MVPA. Obese individuals accumulated less PA than their normal-weight counterparts, whether considering PAEE or allometrically-scaled PAEE (- 10 kJ•day- 1•kg- 1 or - 15 kJ•day- 1•kg-2/3 in men). Higher income and manual work were associated with higher PA; manual workers recorded 13-16 kJ•kg- 1•day- 1 more PAEE than sedentary counterparts. Overall, 86% of women and 96% of men accumulated a daily average of MVPA (> 3 METs) corresponding to 150 min per week. These values were 49 and 74% if only considering bouts > 10 min (15 and 31% for > 4 METs).

CONCLUSIONS

PA varied by age, sex and BMI, and was higher in manual workers and those with higher incomes. Light physical activity was the main driver of PAEE; a component of PA that is currently not quantified as a target in UK guidelines.

Exploring Children's Physical Activity Behaviours According to Location: A Mixed-Methods Case Study

The school environment is ideally placed to facilitate physical activity (PA) with numerous windows of opportunity from break and lunch times, to lesson times and extracurricular clubs. However, little is known about how children interact with the school environment to engage in PA and the other locations they visit daily, including time spent outside of the school environment i.e., evening and weekend locations. Moreover, there has been little research incorporating a mixed-methods approach that captures children’s voices alongside objectively tracking children’s PA patterns. The aim of this study was to explore children’s PA behaviours according to different locations. Sixty children (29 boys, 31 girls)—35 key stage 2 (aged 9–11) and 25 key stage 3 (aged 11–13)—wore an integrated global positioning systems (GPS) and heart rate (HR) monitor over four consecutive days. A subsample of children (n = 32) were invited to take part in one of six focus groups to further explore PA behaviours and identify barriers and facilitators to PA. Children also completed a PA diary. The KS2 children spent significantly more time outdoors than KS3 children (p = 0.009). Boys engaged in more light PA (LPA) when on foot and in school, compared with girls (p = 0.003). KS3 children engaged in significantly more moderate PA (MPA) at school than KS2 children (p = 0.006). Focus groups revealed fun, enjoyment, friends, and family to be associated with PA, and technology, costs, and weather to be barriers to PA. This mixed methodological study highlights differences in the PA patterns and perceptions of children according to age and gender. Future studies should utilize a multi-method approach to gain a greater insight into children’s PA patterns and inform future health policies that differentiate among a range of demographic groups of children.

Accelerometer-Measured Physical Activity and Sedentary Behavior Patterns in Taiwanese Adolescents

Levels of physical activity and sedentary behavior among adolescents seem to vary within different settings, but few Asian studies have compared physical activity and sedentary activity patterns in adolescents across weekdays/weekends and during-school time/after-school time. This study aimed to provide objectively measured data describing intensity-specific physical activity and sedentary behavior patterns in Taiwanese adolescents. The results were sorted by gender and divided between weekdays/weekends and during-school time/after-school time. A total of 470 Taiwanese students (49.6% boys, ages 12–15 y) were recruited and fitted with GT3X+ accelerometers for seven days. Intensity-specific physical activity, total sedentary time, and sedentary bouts (number and duration ≥30 min) were measured. The Mann-Whitney U test was used to examine the significant differences in physical activity and sedentary behavior patterns between the genders on weekdays/weekends and during school/after-school time. The results show that the adolescents’ overall activity levels were below recommended thresholds, with girls engaging in significantly less moderate to vigorous physical activity, having longer sedentary time, longer time spent in sedentary bouts, and more frequent sedentary bouts than boys. Similar results were observed in physical activities of each intensity as well as sedentary behavior variables, both on weekdays/weekends and during-school/after-school periods. These findings emphasize the importance of developing and implementing approaches to increase moderate to vigorous physical activity, as well as decrease prolonged sedentary time and long sedentary bouts, especially for Taiwanese girls.

Whole family-based physical activity promotion intervention: the Families Reporting Every Step to Health pilot randomised controlled trial protocol

INTRODUCTION

Family-based physical activity (PA) interventions present a promising avenue to promote children's activity; however, high-quality experimental research is lacking. This paper describes the protocol for the FRESH (Families Reporting Every Step to Health) pilot trial, a child-led family-based PA intervention delivered online.

METHODS AND ANALYSIS

FRESH is a three-armed, parallel-group, randomised controlled pilot trial using a 1:1:1 allocation ratio with follow-up assessments at 8 and 52 weeks postbaseline. Families will be eligible if a minimum of one child in school Years 3-6 (aged 7-11 years) and at least one adult responsible for that child are willing to participate. Family members can take part in the intervention irrespective of their participation in the accompanying evaluation and vice versa.Following baseline assessment, families will be randomly allocated to one of three arms: (1) FRESH; (2) pedometer-only or (3) no-intervention control. All family members in the pedometer-only and FRESH arms receive pedometers and generic PA promotion information. FRESH families additionally receive access to the intervention website; allowing participants to select step challenges to 'travel' to target cities around the world, log steps and track progress as they virtually globetrot. Control families will receive no treatment. All family members will be eligible to participate in the evaluation with two follow-ups (8 and 52 weeks). Physical (eg, fitness and blood pressure), psychosocial (eg, social support) and behavioural (eg, objectively measured family PA) measures will be collected at each time point. At 8-week follow-up, a mixed methods process evaluation will be conducted (questionnaires and family focus groups) assessing acceptability of the intervention and evaluation. FRESH families' website engagement will also be explored.

ETHICS AND DISSEMINATION

This study received ethical approval from the Ethics Committee for the School of the Humanities and Social Sciences at the University of Cambridge. Findings will be disseminated via peer-reviewed publications, conferences and to participating families.

TRIAL REGISTRATION NUMBER

ISRCTN12789422.

A process evaluation of the PLAN-A intervention (Peer-Led physical Activity iNtervention for Adolescent girls)

BACKGROUND

Few adolescent girls engage in enough physical activity (PA) to meet recommendations and there is a need for new interventions to increase girls PA. We have previously published the results of the PLAN-A cluster randomised feasibility trial which was a peer-led school-based PA intervention, showing that the intervention was feasible and held promise to increase the PA of girls aged 12-13 years. In PLAN-A, pupils nominated by their peers as influential attend training to teach them how to influence, promote and normalise physical activity amongst their peer-group. This paper reports the results of the process evaluation of the PLAN-A feasibility study, specifically focussing on acceptability to key stakeholders, intervention fidelity, receipt/experiences and perceived effect and suggested intervention refinements before proceeding to a definitive RCT.

METHODS

A mixed-methods process evaluation triangulated data from qualitative focus groups and interviews with peer-supporter and non peer-supporter pupils (N = 52), parents (N = 12), teachers (N = 6) and intervention training deliverers (N = 5), quantitative questionnaires, and observations of intervention delivery. Quantitative data were analysed descriptively, and qualitative data were analysed with the Framework Method.

RESULTS

The duration, timings, content and delivery of the peer-supporter training were acceptable. There was good fidelity to the intervention manual and its underpinning theory including high fulfilment of session objectives and use of an autonomy-supportive motivational style. Peer-supporters engaged with and enjoyed the training and retained key peer-supporter messages (what counts as PA, encouragement, empathy and subtlety). Parents and teachers were supportive of the intervention and reported perceived effects including increased PA and awareness of it, improved peer relationships, and confidence. Suggested intervention refinements included increasing participatory learning, reducing technical jargon, and providing more support to overcome challenges to giving peer support.

CONCLUSIONS

PLAN-A can be delivered as planned, is well-received, and appears to be effective in empowering adolescent girls to support their peer group to become more active. The refinements identified can be made within the original intervention structure, before proceeding to a definitive trial.

TRIAL REGISTRATION

ISCTRN, ISRCTN12543546 , Registered on 28/7/2015.

A peer-led physical activity intervention in schools for adolescent girls: a feasibility RCT

Background

Girls are less active than boys and few adolescent girls meet physical activity (PA) guidelines. Peers are an important influence on the views and behaviours of adolescent girls, yet many PA interventions involving peers use formal approaches that may not harness the power of peer groups. More informal peer-led PA interventions, which work within proximal peer groups, may hold promise for increasing girls’ PA.

Objectives

To examine the feasibility, evidence of promise and cost of the Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A), a peer-led PA intervention.

Design

Phase 1 comprised formative work and a pilot study conducted in one secondary school. Phase 2 was a feasibility study comprising a pilot randomised controlled trial in six secondary schools, including process and economic evaluations.

Setting

Six secondary schools in South Gloucestershire and Wiltshire, recruited from schools above the median local Pupil Premium (i.e. more deprived).

Participants

Year 8 girls (aged 12–13 years).

Intervention

Year 8 girls nominated other girls in their year who are likely to be influential (e.g. who they look up to, are good listeners); the 18% most nominated were invited to be peer supporters (PSs). PSs attended 2 consecutive days of training (plus a top-up day 5 weeks later) outside the school site, led by pairs of PS trainers, to increase their knowledge about PA and their capabilities and confidence to promote PA in their friendship group.

Main outcome measures

Measures focused on establishing evidence for feasibility and promise: recruitment and retention of Year 8 girls and PSs, data provision rates [accelerometer and questionnaire collected pre randomisation/beginning of Year 8 (T0), end of Year 8 (T1) and beginning of Year 9 (T2)], intervention acceptability, PS training attendance, intervention cost, and the between-arm difference in weekday minutes of moderate to vigorous PA (MVPA). A process evaluation was conducted.

Results

Six schools were recruited: four PLAN-A (n = 269) and two control (n = 158). In total, 94.7% of Year 8 girls participated. A total of 55 (17–24% of Year 8 girls) PSs were trained (attendance rate 91–100%). Five girls were trained as PS trainers. Questionnaire data provision exceeded 92% at all time points. Accelerometer return rates were > 85% and wear-time criteria were met by 83%, 71% and 62% of participants at T0, T1 and T2, respectively. Mean weekday MVPA did not differ between intervention arms at T1 (1.1 minutes, 95% CI –4.3 to 6.5 minutes) but did at T2 (6.1 minutes, 95% CI 1.4 to 10.8 minutes), favouring PLAN-A. The mean cost of intervention delivery was £2685 per school or £37 per Year 8 girl. Process evaluation identified good fidelity, engagement and enjoyment of the PS training and peer-support strategies. PSs needed more guidance on how to start conversations.

Limitations

Accelerometer data provision was lowest at T2, suggesting a need for strategies to increase compliance.

Conclusions

Informal peer-led intervention approaches, such as PLAN-A, hold promise as a means of promoting PA to adolescent girls.

Future work

A definitive randomised controlled trial of PLAN-A is warranted.

Trial registration

Current Controlled Trials ISRCTN12543546.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 7, No. 16. See the NIHR Journals Library website for further project information. The work was undertaken with the support of the Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), a UK Clinical Research Collaboration (UKCRC) Public Health Research Centre of Excellence. Joint funding (MR/KO232331/1) from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the Welsh Government and the Wellcome Trust, under the auspices of the UKCRC, is gratefully acknowledged. This study was designed and delivered in collaboration with the Bristol Randomised Trials Collaboration (BRTC), a UK CRC-registered clinical trials unit in receipt of NIHR clinical trials unit support funding. The intervention costs were jointly funded by South Gloucestershire Council and Wiltshire Council.

Factors associated with accelerometer measured movement behaviours among White British and South Asian children aged 6-8 years during school terms and school holidays

OBJECTIVES

To investigate factors associated with movement behaviours among White British (WB) and South Asian (SA) children aged 6-8 years during school terms and holidays.

DESIGN

Cross-sectional.

SETTING

Three primary schools from the Bradford area, UK.

PARTICIPANTS

One hundred and sixty WB and SA children aged 6-8 years.

PRIMARY AND SECONDARY OUTCOMES

Sedentary behaviour (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) measured by accelerometry during summer, winter and spring and during school terms and school holidays. Data were analysed using multivariate mixed-effects multilevel modelling with robust SEs. Factors of interest were ethnicity, holiday/term, sex, socioeconomic status (SES), weight status, weekend/weekday and season.

RESULTS

One hundred and eight children (67.5%) provided 1157 valid days of data. Fifty-nine per cent of children were WB (n=64) and 41% (n=44) were SA. Boys spent more time in MVPA (11 min/day, p=0.013) compared with girls and SA children spent more time in SB (39 min, p=0.017) compared with WB children in adjusted models. Children living in higher SES areas were more sedentary (43 min, p=0.006) than children living in low SES areas. Children were more active during summer (15 min MVPA, p<0.001; 27 LPA, p<0.001) and spring (15 min MVPA, p=0.005; 38 min LPA, p<0.001) and less sedentary (-42 min and -53 min, p<0.001) compared with winter. Less time (8 min, p=0.012) was spent in LPA during school terms compared with school holidays. Children spent more time in MVPA (5 min, p=0.036) during weekend compared with weekdays. Overweight and obese children spent more time in LPA (21 min, p=0.021) than normal-weight children.

CONCLUSION

The results of our study suggest that significant child level factors associated with movement behaviours are ethnicity, sex, weight-status and area SES. Significant temporal factors are weekends, school holidays and seasonality. Interventions to support health enhancing movement behaviours may need to be tailored around these factors.

Protocol for a cluster randomised controlled trial of a Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A)

Background

Adolescent girls are less physically active than recommended for health, and levels decline further as they approach adulthood. Peers can influence adolescent girls’ physical activity. Interventions capitalising on peer support could positively impact physical activity behaviour in this group. Building on promising feasibility work, the purpose of this cluster randomised controlled trial is to assess whether the Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A) increases adolescent girls’ physical activity and is cost effective.

Methods

PLAN-A is a two-arm secondary school-based cluster randomised controlled trial, conducted with girls aged 13–14 years from twenty schools in the south west of England. The intervention requires participants to nominate influential girls within their year group to become peer supporters. The top 15% of girls nominated in each school receive three days of training designed to prepare them to support their peers to be more physically active during a ten-week intervention period. Data will be collected at two time points, at baseline (T0) and 5–6 months post-intervention (T1). Schools will be randomly allocated to the intervention (n = 10) or control (n = 10) arm after T0. At each time point, all consenting participants will wear an accelerometer for seven days to assess the primary outcome of mean weekday minutes of moderate-to-vigorous physical activity. Multivariable mixed effects linear regression will be used to estimate differences in the primary outcome between the two arms and will be examined on an Intention-to-Treat (ITT) basis. A self-report psychosocial questionnaire will be completed by participants to assess self-esteem and physical activity motivation. Resource use and quality of life will be measured for the purposes of an economic evaluation. A mixed-methods process evaluation will be conducted to explore intervention fidelity, acceptability and sustainability. Analysis of quantitative process evaluation data will be descriptive, and the framework method will be used to analyse qualitative data.

Discussion

This paper describes the protocol for the PLAN-A cluster randomised controlled trial, a novel approach to increasing adolescent girls’ physical activity levels through peer support.

Trial registration

ISRCTN14539759–31 May, 2018.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7012-x) contains supplementary material, which is available to authorized users.

Associations of Participation in Organized Sport and Self-Organized Physical Activity in Relation to Physical Activity Level Among Adolescents

Although physical activity level (PAL) is positively correlated with adolescents' health, many adolescents do not fulfill recommendations for physical activity. This study examines the associations of organized sport and self-organized physical activity, with PAL among adolescents. Participants were 301 adolescents (12-13 year-olds). The adolescents wore accelerometers for 1 week according to international standards, and reported their participation in organized sport and self-organized physical activity in a questionnaire. The results showed that the level of participation in organized sport was positively associated with the adolescents' total PAL, while there was no significant association between time spent in self-organized physical activity and adolescents' daily minutes of moderate and vigorous physical activity. In addition, boys who participated <3 h per week (or not at all) in organized sport stood out with the lowest fulfillment of recommended PAL. Our findings underline the critical importance of getting adolescents, especially boys, to participate in organized sport and not to drop out from organized sport during adolescence.

Dietary Habits and Physical Activity of 18-Year-Old Adolescents in Relation to Overweight and Obesity

BACKGROUND

The purpose of this study was to evaluate the correlations between the nutritional status, nutritional habits, and physical activity in the representative population of 18-year-old students.

METHODS

A total of 1,631 participants aged 18 years, originating from secondary schools/senior high schools in the city of Bialystok, Szpitalna, Bialystok, Poland were enrolled. Participants completed anonymous questionnaires, and their body mass index was assessed. Data were analyzed using standard statistical procedures with Statistical PL 12.0.

RESULTS

The analysis showed that consumption of only one to two or three meals was associated with an increased risk of overweight and obesity-in case of one or two meals among girls, OR=1.78 (P<0.05), in case of one or two meals among boys, OR=2.325 (P<0.01), and in case of three meals, OR=1.771 (P<0.05). First breakfast was consumed by 82.1% of boys with normal BMI and 73.1% overweight and obesity (OR=0.593; P<0.05). 24.5% of the eutrophic compared to only 20.3% of adolescents with elevated BMI reported attending all PE classes. Physical activity undertaken after school was associated with a 35.9% decrease risk of overweight and obesity among girls and 57.7% among boys.

CONCLUSION

A specific pattern of nutritional habits, that is, decreased meal frequency in adolescents, skipping meals, appear the most frequent nutritional mistakes associated with overweight and obesity. Insufficient physical activity and exposure to sedentary behaviors among adolescents are disturbing. The obesity problem requires monitoring, prevention and the change of nutritional habits and physical activity early in childhood.

The development and feasibility of a randomised family-based physical activity promotion intervention: the Families Reporting Every Step to Health (FRESH) study

Background

There is a need for high-quality research aiming to increase physical activity in families. This study assessed the feasibility and acceptability of FRESH (Families Reporting Every Step to Health), a child-led family-based physical activity intervention delivered online.

Methods

In a two-armed randomised feasibility study, 12 families (with an 8–10-year-old index child) were allocated to a ‘child-only’ (CO) or ‘family’ arm (FAM) of the theory-based FRESH intervention. Both received access to the FRESH website, allowing participants to select step challenges to ‘travel’ to target cities around the world, log their steps, and track their progress as they virtually globetrot. Only index children wore pedometers in CO; in FAM, all family members wore pedometers and worked towards collective goals. All family members were eligible to participate in the evaluation. Mixed-methods process evaluation (questionnaires and family focus groups) at 6-week follow-up consisted of completing questionnaires assessing acceptability of the intervention and accompanying effectiveness evaluation, focussed on physical (e.g. fitness, blood pressure), psychosocial (e.g. social support), and behavioural (e.g. objectively-measured family physical activity) measures.

Results

All families were retained (32 participants). Parents enjoyed FRESH and all children found it fun. More FAM children wanted to continue with FRESH, found the website easy to use, and enjoyed wearing pedometers. FAM children also found it easier to reach goals. Most CO families would have preferred whole family participation. Compared to CO, FAM exhibited greater website engagement as they travelled to more cities (36 ± 11 vs. 13 ± 8) and failed fewer challenges (1.5 ± 1 vs. 3 ± 1). Focus groups also revealed that most families wanted elements of competition. All children enjoyed being part of the evaluation, and adults disagreed that there were too many intervention measures (overall, 2.4 ± 1.3) or that data collection took too long (overall, 2.2 ± 1.1).

Conclusion

FRESH was feasible and acceptable to participating families; however, findings favoured the FAM group. Recruitment, intervention fidelity and delivery and some measurement procedures are particular areas that require further attention for optimisation. Testing the preliminary effectiveness of FRESH on family physical activity is a necessary next step.

Trial registration

This study was registered and given an International Standard Randomised Controlled Trials Number (ISRCTN12789422). Registered 16 March 2016. http://www.isrctn.com/ISRCTN12789422

Heart Rate and Perceived Experience Differ Markedly for Children in Same- versus Mixed-Gender Soccer Played as Small- and Large-Sided Games

This study examines heart rate (HR) and perceived experience during same- versus mixed-gender soccer played as small- (SSG) and large-sided (LSG) games. HR, rating of perceived exertion (RPE), and fun scores were determined in 134 pupils (50 girls, 84 boys) randomly assigned to same- and mixed-genders formats playing 2x15-min of SSG (2v2, 4v4) and LSG (12v12) in a random order (~50 m²/player). HR was lower (p≤0.03) for girls when playing together with boys than when playing alone (71±10 versus 77±7%HRmax), while being similar for boys playing mixed- or same-gender games (74±7 versus 77±4%HRmax). Boys perceived less fun when playing together with girls than when playing alone (4.4±2.3 versus 6.3±2.3, p<0.001). Irrespective of gender, higher (p<0.001) HRmean, %time>80%HRmax, and RPE were observed during 2v2 (78±9%HRmax, 43±33%, 5.5±2.5) and 4v4 (76±9%HRmax, 39±32%, 5.5±2.7) than during 12v12 (70±10%HRmax, 23±27%, 3.8±2.9). Cardiovascular strain was lower for girls when playing together with boys than when playing alone in LSG. SSG were more intense than LSG when girls played mixed-gender games and when boys played mixed- and same-gender games. When boys played mixed-gender games, SSG were considered more fun than LSG. Physical education teachers and coaches should consider gender and game format differences when using soccer.

Association Between Self-Reported and Objective Activity Levels by Demographic Factors: Ecological Momentary Assessment Study in Children

BACKGROUND

To address the limitations of the retrospective self-reports of activity, such as its susceptibility to recall bias, researchers have shifted toward collecting real-time activity data on mobile devices via ecological momentary assessment (EMA). Although EMA is becoming increasingly common, it is not known how EMA self-reports of physical activity and sedentary behaviors relate to the objective measures of activity or whether there are factors that may influence the strength of association between these two measures. Understanding the relationship between EMA and accelerometry can optimize future instrument selection in studies assessing activity and health outcomes.

OBJECTIVE

The aim of this study was to examine the associations between EMA-reported sports or exercise using the accelerometer-measured moderate-to-vigorous physical activity (MVPA) and EMA-reported TV, videos, or video games with the accelerometer-measured sedentary time (ST) in children during matched 2-h windows and test potential moderators.

METHODS

Children (N=192; mean age 9.6 years; 94/192, 49.0% male; 104/192, 54.2% Hispanic; and 73/192, 38.0% overweight or obese) wore an accelerometer and completed up to 7 EMA prompts per day for 8 days during nonschool time, reporting on past 2-h sports or exercise and TV, videos, or video games. Multilevel models were used to assess the relationship between the accelerometer-measured ST and EMA-reported TV, videos, or video games. Given the zero-inflated distribution of MVPA, 2-part models were used assess the relationship between the accelerometer-measured MVPA and EMA-reported sports or exercise.

RESULTS

EMA-reported TV, videos, or video games were associated with a greater accelerometer-measured ST (beta=7.3, 95% CI 5.5 to 9.0, P<.001). This relationship was stronger in boys (beta=9.9, 95% CI 7.2 to 12.6, P<.001) than that in girls (beta=4.9, 95% CI 2.6 to 7.2, P≤.001). EMA-reported sports or exercise was associated with a greater accelerometer-measured MVPA (zero portion P<.001; positive portion P<.001). This relationship was stronger on weekends, in older children, and in non-Hispanic children (zero portion all P values<.001; positive portion all P values<.001).

CONCLUSIONS

EMA reports highly relate to accelerometer measures. However, the differences in the strength of association depending on various demographic characteristics suggest that future research should use both EMA and accelerometers to measure activity to collect complementary activity data.

Results of a feasibility cluster randomised controlled trial of a peer-led school-based intervention to increase the physical activity of adolescent girls (PLAN-A)

BACKGROUND

Most adolescent girls in the UK do not meet government physical activity recommendations and effective interventions are needed. This study reports the results of a feasibility trial of PLAN-A, a novel school-based peer-led physical activity intervention for adolescent girls.

METHODS

A two-arm cluster randomised controlled feasibility study was conducted in six English secondary schools (4 intervention & 2 control). Year 8 (age 12-13) girls were eligible and randomisation was at school-level. The intervention involved training Year 8 girls (out of school for two consecutive days, plus one top-up day 5 weeks later), who were identified by their peers as influential, to provide informal support to their friends to increase their physical activity. Feasibility of the intervention and the research was examined, including: recruitment, training attendance and data provision rates, evidence of promise of the intervention to affect weekday moderate-to-vigorous physical activity (MVPA), intervention cost and estimation of the sample size for a definitive trial. Accelerometer and questionnaire data were collected at the beginning of Year 8 (Time 0), the end of Year 8 (10-weeks after peer-supporter training) and the beginning of Year 9 (Time 2).

RESULTS

Four hundred twenty-seven girls were recruited (95% recruitment rate). 55 girls consented to be a peer-supporter and 53 peer-supporters were trained (97% of those invited). Accelerometer return rates exceeded 85% at each time point and wear time criteria was met by 83%, 71% and 62% participants at Time 0, 1 and 2 respectively. Questionnaire data were provided by >91% of participants at each time point. Complete-case adjusted linear regression analysis showed evidence of a 6.09 minute (95% CI = 1.43, 10.76) between-arms difference in weekday MVPA at Time 2 in favour of the intervention arm. On average PLAN-A cost £2685 per school to deliver (£37 per Year 8 girl). There were no adverse events. A trial involving 20 schools would be adequately powered to detect a between-arms difference in weekday MVPA of at least six minutes.

CONCLUSIONS

The PLAN-A intervention adopts a novel peer-led approach, is feasible, and shows evidence of promise to positively affect girls' physical activity levels. A definitive trial is warranted.

TRIAL REGISTRATION

ISCTRN, ISRCTN12543546, Registered on 28/7/2015, URL of registry record: http://www.isrctn.com/ISRCTN12543546.

Associations of serum leptin, ghrelin and peptide YY levels with physical activity and cardiorespiratory fitness in adolescent boys with different BMI values

The aim of this study was to investigate the differences in associations of serum acylated and des-acylated ghrelin, peptide YY (PYY) and leptin levels with physical activity (PA) and cardiorespiratory fitness (CReF) in adolescent boys (mean age of 14.0 years) with overweight (OWB; n=55) and with normal weight (NWB; n=154).

METHODS

Total PA was measured by 7-day accelerometry (counts/min) and CReF by peak oxygen consumption (VO²peak/kg).

RESULTS

No differences were found in serum PYY, acylated ghrelin or des-acyl ghrelin levels, whereas mean leptin (11.6±10.6 vs. 2.0±2.7 ng/ml; p<0.05) and insulin (18.1±8.7 vs. 11.0±6.2 mU/l; p<0.05) levels were significantly higher in OWB compared to NWB. Mean CReF was significantly lower in OWB compared to NWB (39.7±8.7 vs. 50.5±6.8 ml/min/kg; p<0.05). Leptin was negatively correlated with CReF in both groups (r=-0.43; p<0.05), des-acylated ghrelin with CReF only in OWB (r =-0.36; p<0.05). In OWB leptin was negatively correlated with total PA (r=-0.32; p<0.05) and positively with sedentary time of PA (r=0.35; p<0.05). In NWB 28.1% of the variability of CReF was determined by leptin and insulin resistance index (HOMA-IR), whereas in OWB 71.9% was determined by trunk FM and BMI.

CONCLUSIONS

Leptin concentration was inversely associated with CReF in adolescent boys independently of BMI in both groups, while des-acylated ghrelin was associated with CReF only in OWB. Low PA in OWB was associated with high serum leptin level.

An investigation of bra concerns and barriers to participation in horse riding

Horse riding is a female-dominated sport where participation levels are declining. The influence of the breast on participation levels and current satisfaction with bras for this activity is unknown. This study aimed to investigate bra concerns and breast-related barriers to participation in horse riding. A 6-part, 32 question online survey was completed by 1,324 females who participated in horse riding. Descriptive and chi-squared analyses were utilised; inductive content analysis was completed to analyse qualitative responses. At least one breast-related barrier was reported by 25% of all participants. Larger-breasted riders were less satisfied (P<0.001) with their bras. 70% of riders stated that improvements needed to be made in bras to help reduce breast health issues, with support, style and fit the most common reasons cited. This study highlights the importance of addressing breast-related barriers and provides rationale for the development of equestrian-specific breast support garments and educational initiatives.

Physical Activity Duration but Not Energy Expenditure Differs between Daily and Intermittent Breakfast Consumption in Adolescent Girls: A Randomized Crossover Trial

Background

It is not known whether breakfast frequency affects physical activity (PA) in children or adolescents.

Objective

This study examined the effect of daily compared with intermittent breakfast consumption on estimated PA energy expenditure (PAEE) in adolescent girls.

Methods

Under a randomized crossover design, 27 girls [mean ± SD age: 12.4 ± 0.5 y, body mass index (in kg/m2): 19.3 ± 3.0] completed two 7-d conditions. A standardized breakfast (∼1674 kJ) was consumed every day before 0900 in the daily breakfast consumption (DBC) condition. The standardized breakfast was consumed on only 3 d before 0900 in the intermittent breakfast consumption (IBC) condition, alternating with breakfast omission on the remaining 4 d (i.e., only water consumed before 1030). Combined heart rate accelerometry was used to estimate PAEE throughout each condition. Statistical analyses were completed by using condition × time of day repeated-measures ANOVA. The primary outcome was PAEE and the secondary outcome was time spent in PA.

Results

Daily estimated PAEE from sedentary or light-, moderate-, or vigorous-intensity PA and total PAEE were not significantly different between the conditions. The condition × time of day interaction for sedentary time (P = 0.05) indicated that the girls spent an additional 11.5 min/d being sedentary in the IBC condition compared with the DBC condition from 1530 to bedtime (P = 0.04). Light PA was 19.8 min/d longer in the DBC condition than in the IBC condition (P = 0.05), which was accumulated from waking to 1030 (P = 0.04) and from 1530 to bedtime (P = 0.03). There were no significant differences in time spent in moderate PA or vigorous PA between the conditions.

Conclusions

Adolescent girls spent more time in light PA before 1030 and after school and spent less time sedentary after school when a standardized breakfast was consumed daily than when consumed intermittently across 7 d. However, breakfast manipulation did not affect estimated daily PAEE. This trial was registered at www.isrctn.com as ISRCTN74579070.

Clustering of multiple energy balance related behaviors is associated with body fat composition indicators in adolescents: Results from the HELENA and ELANA studies

The objective of this study was to identify clustering patterns of four energy balance-related behaviors (EBRB): television (TV) watching, moderate and vigorous physical activity (MVPA), consumption of fruits and vegetables (F&V), and consumption of sugar-sweetened beverages (SSB), among European and Brazilian adolescents. EBRB associations with different body fat composition indicators were then evaluated. Participants included adolescents from eight European countries in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescents) study (n = 2,057, 53.8% female; age: 12.5-17.5 years) and from the metropolitan region of Rio de Janeiro/Brazil in the ELANA study (the Adolescent Nutritional Assessment Longitudinal Study) (n = 968, 53.2% female; age: 13.5-19 years). EBRB data allowed for sex- and study-specific clusters. Associations were estimated by ANOVA and odds ratios. Five clustering patterns were identified. Four similar clusters were identified for each sex and study. Among boys, different cluster identified was characterized by high F&V consumption in the HELENA study and high TV watching and high MVPA time in the ELANA study. Among girls, the different clusters identified was characterized by high F&V consumption in both studies and, additionally, high SSB consumption in the ELANA study. Regression analysis showed that clusters characterized by high SSB consumption in European boys; high TV watching, and high TV watching plus high MVPA in Brazilian boys; and high MVPA, and high SSB and F&V consumption in Brazilian girls, were positively associated with different body fat composition indicators. Common clusters were observed in adolescents from Europe and Brazil, however, no cluster was identified as being completely healthy or unhealthy. Each cluster seems to impact on body composition indicators, depending on the group. Public health actions should aim to promote adequate practices of EBRB.

Equity effects of children's physical activity interventions: a systematic scoping review

BACKGROUND

Differential effects of physical activity (PA) interventions across population sub-groups may contribute to inequalities in health. This systematic scoping review explored the state of the evidence on equity effects in response to interventions targeting children's PA promotion. The aims were to assess and summarise the availability of evidence on differential intervention effects of children's PA interventions across gender, body mass index, socioeconomic status, ethnicity, place of residence and religion.

METHODS

Using a pre-piloted search strategy, six electronic databases were searched for controlled intervention trials, aiming to increase PA in children (6-18 years of age), that used objective forms of measurement. Screening and data extraction were conducted in duplicate. Reporting of analyses of differential effects were summarized for each equity characteristic and logistic regression analyses run to investigate intervention characteristics associated with the reporting of equity analyses.

RESULTS

The literature search identified 13,052 publications and 7963 unique records. Following a duplicate screening process 125 publications representing 113 unique intervention trials were included. Although the majority of trials collected equity characteristics at baseline, few reported differential effects analyses across the equity factors of interest. All 113 included interventions reported gender at baseline with 46% of non-gender targeted interventions reporting differential effect analyses by gender. Respective figures were considerably smaller for body mass index, socioeconomic status, ethnicity, place of residence and religion. There was an increased likelihood of studying differential effects in school based interventions (OR: 2.9 [1.2-7.2]) in comparison to interventions in other settings, larger studies (per increase in 100 participants; 1.2 [1.0 - 1.4]); and where a main intervention effect on objectively measured PA was reported (3.0 [1.3-6.8]).

CONCLUSIONS

Despite regularly collecting relevant information at baseline, most controlled trials of PA interventions in children do not report analyses of differences in intervention effect across outlined equity characteristics. Consequently, there is a scarcity of evidence concerning the equity effects of these interventions, particularly beyond gender, and a lack of understanding of subgroups that may benefit from, or be disadvantaged by, current intervention efforts. Further evidence synthesis and primary research is needed to effectively understand the impact of PA interventions on existing behavioural inequalities within population subgroups of children.

TRIAL REGISTRATION

PROSPERO (PROSPERO 2016: CRD42016034020 ).

A cluster randomised controlled trial to evaluate the effectiveness and cost-effectiveness of the GoActive intervention to increase physical activity among adolescents aged 13-14 years

INTRODUCTION

Adolescent physical activity promotion is rarely effective, despite adolescence being critical for preventing physical activity decline. Low adolescent physical activity is likely to last into adulthood, increasing health risks. The Get Others Active (GoActive) intervention is evidence-based and was developed iteratively with adolescents and teachers. This intervention aims to increase physical activity through increased peer support, self-efficacy, group cohesion, self-esteem and friendship quality, and is implemented using a tiered-leadership system. We previously established feasibility in one school and conducted a pilot randomised controlled trial (RCT) in three schools.

METHODS AND ANALYSIS

We will conduct a school-based cluster RCT (CRCT) in 16 secondary schools targeting all year 9 students (n=2400). In eight schools, GoActive will run for two terms: weekly facilitation support from a council-funded intervention facilitator will be offered in term 1, with more distant support in term 2. Tutor groups choose two weekly activities, encouraged by older adolescent mentors and weekly peer leaders. Students gain points for trying new activities; points are entered into a between-class competition. Outcomes will be assessed at baseline, interim (week 6), postintervention (week 14-16) and 10-month follow-up (main outcome). The primary outcome will be change from baseline in daily accelerometer-assessed moderate-to-vigorous physical activity. Secondary outcomes include accelerometer-assessed activity intensities on weekdays/weekends; self-reported physical activity and psychosocial outcomes; cost-effectiveness and cost-utility analyses; mixed-methods process evaluation integrating information from focus groups and participation logs/questionnaires.

ETHICS AND DISSEMINATION

Ethical approval for the conduct of the study was gained from the University of Cambridge Psychology Research Ethics Committee. Given the lack of rigorously evaluated interventions, and the inclusion of objective measurement of physical activity, long-term follow-up and testing of causal pathways, the results of a CRCT of the effectiveness and cost-effectiveness of GoActive are expected to add substantially to the limited evidence on adolescent physical activity promotion. Workshops will be held with key stakeholders including students, parents, teachers, school governors and government representatives to discuss plans for wider dissemination of the intervention.

TRIAL REGISTRATION NUMBER

ISRCTN31583496.

Cross-Sectional Associations of Objectively-Measured Physical Activity and Sedentary Time with Body Composition and Cardiorespiratory Fitness in Mid-Childhood: The PANIC Study

BACKGROUND

The minimum intensity of physical activity (PA) that is associated with favourable body composition and cardiorespiratory fitness (CRF) remains unknown.

OBJECTIVE

To investigate cross-sectional associations of PA and sedentary time (ST) with body composition and CRF in mid-childhood.

METHODS

PA, ST, body composition and CRF were measured in a population-based sample of 410 children (aged 7.6 ± 0.4 years). Combined heart-rate and movement sensing provided estimates of PA energy expenditure (PAEE, kJ/kg/day) and time (min/day) at multiple fine-grained metabolic equivalent (MET) levels, which were also collapsed to ST and light PA (LPA), moderate PA (MPA) and vigorous PA (VPA). Fat mass index (FMI, kg/m2), trunk fat mass index (TFMI, kg/m2) and fat-free mass index (FFMI, kg/m2.5) were derived from dual-energy X-ray absorptiometry. Maximal workload from a cycle ergometer test provided a measure of CRF (W/kg FFM). Linear regression and isotemporal substitution models were used to investigate associations.

RESULTS

The cumulative time above 2 METs (221 J/min/kg) was inversely associated with FMI and TFMI in both sexes (p < 0.001) whereas time spent above 3 METs was positively associated with CRF (p ≤ 0.002); CRF increased and adiposity decreased dose-dependently with increasing MET levels. ST was positively associated with FMI and TFMI (p < 0.001) but there were inverse associations between all PA categories (including LPA) and adiposity (p ≤ 0.002); the magnitude of these associations depended on the activity being displaced in isotemporal substitution models but were consistently stronger for VPA. PAEE, MPA and to a greater extent VPA, were all positively related to CRF (p ≤ 0.001).

CONCLUSIONS

PA exceeding 2 METs is associated with lower adiposity in mid-childhood, whereas PA of 3 METs is required to benefit CRF. VPA was most beneficial for fitness and fatness, from a time-for-time perspective, but displacing any lower-for-higher intensity may be an important first-order public health strategy. Clinical trial registry number (website): NCT01803776 ( https://clinicaltrials.gov/ct2/show/NCT01803776 ).

Global participation in sport and leisure-time physical activities: A systematic review and meta-analysis

This review aimed to determine the most popular physical activities performed by children, adolescents, and adults globally. Statistic bureau websites and article databases Scopus, ProQuest, SPORTDiscus, and Science Direct were searched between November 17th, 2014 and April 31st, 2015. Eligible studies were published in the last 10years with participation rates for specific physical activities among individuals five years or older. Data extraction for included articles (n=64) was assessed independently and agreed upon by two authors. A random-effects model was used to calculate participation rates in specific activities for each age group and region. In total 73,304 articles were retrieved and 64 articles representing 47 countries were included in the final meta-analysis. Among adults, walking was the most popular activity in the Americas (18.9%; 95% CI 10.2 to 32.5), Eastern Mediterranean (15.0%; 95% CI 5.8 to 33.6), Southeast Asia (39.3%; 95% CI 0.9 to 98.0) and Western Pacific (41.8%; 95% CI 25.2 to 60.6). In Europe and Africa, soccer (10.0%; 95% CI 6.5 to 15.1) and running (9.3%; 95% CI 0.9 to 53.9), respectively, were top activities. Child and adolescent participation results were highly dependent upon region. American youth team sport participation was high, while youth from the Eastern Mediterranean and Western Pacific were more likely to report participation in lifelong physical activities. Global data for adults reflects a consistent pattern of participation in running and walking. Among all age groups and regions soccer was popular. In children and adolescents, preferences were variable between regions.

Proportion of children meeting recommendations for 24-hour movement guidelines and associations with adiposity in a 12-country study

Background

The Canadian 24-h movement guidelines were developed with the hope of improving health and future health outcomes in children and youth. The purpose of this study was to evaluate adherence to the 3 recommendations most strongly associated with health outcomes in new 24-h movement guidelines and their relationship with adiposity (obesity and body mass index z-score) across countries participating in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE).

Methods

Cross-sectional results were based on 6128 children aged 9–11 years from the 12 countries of ISCOLE. Sleep duration and moderate-to-vigorous physical activity (MVPA) were assessed using accelerometry. Screen time was measured through self-report. Body weight and height were measured. Body mass index (BMI, kg · m⁻²) was calculated, and BMI z-scores were computed using age- and sex-specific reference data from the World Health Organization. Obesity was defined as a BMI z-score > +2 SD. Meeting the overall 24-h movement guidelines was defined as: 9 to 11 h/night of sleep, ≤2 h/day of screen time, and at least 60 min/day of MVPA. Age, sex, highest parental education and unhealthy diet pattern score were included as covariates in statistical models. Associations between meeting vs. not meeting each single recommendation (and combinations) with obesity were assessed with odds ratios calculated using generalized linear mixed models. A linear mixed model was used to examine the differences in BMI z-scores between children meeting vs. not meeting the different combinations of recommendations.

Results

The global prevalence of children meeting the overall recommendations (all three behaviors) was 7%, with children from Australia and Canada showing the highest adherence (15%). Children meeting the three recommendations had lower odds ratios for obesity compared to those meeting none of the recommendations (OR = 0.28, 95% CI 0.18–0.45). Compared to not meeting the 24-h movement recommendations either independently or combined, meeting them was significantly associated with a lower BMI z-score. Whenever the MVPA recommendation was included in the analysis the odds ratios for obesity were lower.

Conclusions

For ISCOLE participants meeting these 3 healthy movement recommendations the odds ratios of being obese or having high BMI z-scores were lower. However, only a small percentage of children met all recommendations. Future efforts should aim to find promising ways to increase daily physical activity, reduce screen time, and ensure an adequate night’s sleep in children.

Trial registration

The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) was registered at ClinicalTrials.gov (Identifier NCT01722500) (October 29, 2012).

Feasibility study and pilot cluster-randomised controlled trial of the GoActive intervention aiming to promote physical activity among adolescents: outcomes and lessons learnt

OBJECTIVES

Assess the feasibility of implementing the GoActive intervention in secondary schools, to identify improvements, test study procedures, determine preliminary effectiveness to increase moderate-to-vigorous physical activity (MVPA), and inform power calculations to establish programme effectiveness.

SETTING

Feasibility study (1 school) and pilot cluster-randomised controlled trial (CRCT; 2 intervention; 1 control school(s)).

PARTICIPANTS

460 participants (46.6% female; 13.2 (0.4) years old).

INTERVENTIONS

8-week intervention (2013) involved: classes choosing weekly activities encouraged by mentors (older adolescents) and in-class peer leaders. Students gain points for trying activities which are entered into an intramural competition.

PRIMARY AND SECONDARY OUTCOME MEASURES

Planned quantitative (questionnaire) and qualitative (focus groups) process evaluation addressed enjoyment, confidence, participation, suggested improvements. Outcomes were assessed at baseline and follow-up (week 8) in pilot CRCT and included accelerometer-assessed MVPA; adolescent-reported activity type, well-being, peer support, shyness, sociability. Analysis of covariance was used to assess preliminary effectiveness as change in MVPA adjusted for baseline.

RESULTS

All year 9 students in intervention schools were exposed to the intervention; over all schools 77% of eligible students were measured. 71% boys and 74% girls found GoActive 'fun'; 38% boys and 32% girls said it increased confidence, and 64% boys and 59% girls said they would continue with a GoActive activity. Suggested improvements included more mentorship; improved training; streamlined points recording. Pilot results indicated potential effectiveness ((adjusted mean difference (95% CI) p value; MVPA mins; 5.1 (1.1 to 9.2) p=0.014)) and suggest recruitment of 16 schools (2400 adolescents) for a full trial. Compared with control, intervention students reported greater peer support 0.5 (0.1 to 0.9) p=0.03, well-being 1.8 (0.1 to 3.4) p=0.04 but no difference in shyness/sociability. Participation in activity types approached significance (intervention group 2.3 (-0.2 to 4.7) p=0.07 more activity types).

CONCLUSIONS

Results suggest feasibility and indicate potential effectiveness of GoActive to increase MVPA and support a fully powered evaluation of effectiveness and cost-effectiveness. Process evaluation data were used to refine GoActive prior to a full trial.

TRIAL REGISTRATION NUMBER

ISRCTN31583496; pre-results.

Changes in Moderate-to-Vigorous Physical Activity Among Older Adolescents

OBJECTIVES

Examined patterns and determinants of objectively measured moderate-to-vigorous physical activity (MVPA) over 4 years in US emerging adults.

METHODS

Waves 1 through 4 (W1 [10th grade] to W4 data of a national cohort starting in 2010 (N = 561; 16.19 ± 0.51 years) were used. MVPA was assessed annually from accelerometers; BMI calculated from measured height/weight; and surveys ascertained self-reported physical activity (PA) planning, peer PA , family support, W1 sociodemographics, W4 school status, W4 residence, and W4 employment. Latent growth modeling estimated trajectories in log-transformed duration (minutes/day) of MVPA and associations with covariates.

RESULTS

Less than 9% of participants met the recommended 60+ minutes/day MVPA across W1 through W4. W1 MVPA was greater in males versus females (B = 0.46, P < .001) and Hispanic versus White (B = 0.34, P < .001) participants. Increased BMI change (W1 to W4 slope) was associated with decreased MVPA. MVPA was positively associated with PA planning (W1-W3: B = 0.10, B = 0.06, B = 0.08, Ps < .05), but not with peer PA or family support. Participants attending 4-year college versus not-attending school (B = 0.52, P < .001), and college students living on campus versus at home (B = 0.37, P < .001) were more likely to engage in MVPA at W4. Weekend MVPA remained relatively constant from W1 through W4.

CONCLUSIONS

High-school students engaged in little MVPA and maintained this low level through the transition to adulthood. Emerging adults' MVPA engagement may vary according to social contexts. Those with high BMI may benefit most from interventions to promote MVPA.

Physical Activity During the Early Years: A Systematic Review of Correlates and Determinants

CONTEXT

Being physically active during the early years (age 0-6 years) is vital for healthy development. Identifying correlates and determinants of physical activity (PA) is crucial to guide effective interventions. This systematic review synthesized studies investigating potential correlates and determinants of PA during the early years, accounting for different types of PA assessment.

EVIDENCE ACQUISITION

Nine electronic databases were searched from inception year (1900) until September 2014; data were analyzed/interpreted in April 2015. The following inclusion criteria were used: written in English, published in peer-reviewed journals, participants not in statutory/school education, and an observational design investigating associations between an exposure/variable, and a quantitative measure of PA. Correlates/determinants of total, moderate to vigorous, and light PA were reported using an ecologic model.

EVIDENCE SYNTHESIS

Of 22,045 identified studies, 130 were included. All took place in high-income countries and few (6%) were of high quality. Correlates of total PA were sex (male, ++); parental PA (+); parental support (+); and time outdoors (+). Determinants of total PA were sex (+) and time spent playing with parents (+). The only correlate of moderate to vigorous PA was sex (male, ++). No determinants of moderate to vigorous or light PA were found. PA correlates/determinants were relatively consistent between objective and subjective PA measures.

CONCLUSIONS

Numerous studies investigated potential correlates and determinants of PA, but overall quality was low. A small number of demographic/biological and social/cultural factors were associated with PA. There is a need for high-quality studies exploring correlates/determinants across all domains of the ecologic model.

Reliability and Validity of the Early Years Physical Activity Questionnaire (EY-PAQ)

Measuring physical activity (PA) and sedentary time (ST) in young children (<5 years) is complex. Objective measures have high validity but require specialist expertise, are expensive, and can be burdensome for participants. A proxy-report instrument for young children that accurately measures PA and ST is needed. The aim of this study was to assess the reliability and validity of the Early Years Physical Activity Questionnaire (EY-PAQ). In a setting where English and Urdu are the predominant languages spoken by parents of young children, a sample of 196 parents and their young children (mean age 3.2 ± 0.8 years) from Bradford, UK took part in the study. A total of 156 (79.6%) questionnaires were completed in English and 40 (20.4%) were completed in transliterated Urdu. A total of 109 parents took part in the reliability aspect of the study, which involved completion of the EY-PAQ on two occasions (7.2 days apart; standard deviation (SD) = 1.1). All 196 participants took part in the validity aspect which involved comparison of EY-PAQ scores against accelerometry. Validty anaylsis used all data and data falling with specific MVPA and ST boundaries. Reliability was assessed using intra-class correlations (ICC) and validity by Bland–Altman plots and rank correlation coefficients. The test re-test reliability of the EY-PAQ was moderate for ST (ICC = 0.47) and fair for moderate-to-vigorous physical activity (MVPA)(ICC = 0.35). The EY-PAQ had poor agreement with accelerometer-determined ST (mean difference = −87.5 min·day⁻¹) and good agreement for MVPA (mean difference = 7.1 min·day⁻¹) limits of agreement were wide for all variables. The rank correlation coefficient was non-significant for ST (rho = 0.19) and significant for MVPA (rho = 0.30). The EY-PAQ has comparable validity and reliability to other PA self-report tools and is a promising population-based measure of young children’s habitual MVPA but not ST. In situations when objective methods are not possible for measurement of young children’s MVPA, the EY-PAQ may be a suitable alternative but only if boundaries are applied.

The relationship between exercise induced bronchial obstruction and health related quality of life in female and male adolescents from a general population

Background

Previous studies have observed that exercise-induced bronchoconstriction (EIB) is more common and more strongly related to exercise related breathing problems in female adolescents than male adolescents. However, few studies have investigated the association between EIB and health related quality of life (HRQoL) from a gender perspective. The aim of this study was to examine the association between EIB and HRQoL and physical activity level in female and male adolescents with and without EIB.

Methods

From a population based study on exercise-induced breathing problems among adolescents (13–15 years, n = 3838) a cross sectional study with prospective data collection was carried out in a random subsample of 140 adolescents. The subjects in the sample were tested for EIB with a standardised exercise test, of which 49 adolescents were tested positive. HRQoL was assessed with the Pediatric Quality of Life Inventory (PedsQL) and the adolescents’ physical activity levels were measured objectively with accelerometer.

Results

The female subjects with EIB reported a lower HRQoL, both in total score (p = 0.03) and physical functioning score (p = 0.009) and had a lower baseline FEV₁ compared to females without EIB (88 vs. 94 % predicted, p = 0.001). No differences were found in HRQoL or baseline lung function between males with or without EIB. There were no differences in minutes of moderate to vigorous physical activity per day between females or males with and without EIB.

Conclusion

In a general population, the female adolescents with EIB had lower HRQoL and poorer baseline lung function compared to counterparts without EIB. These differences were not observed in males. EIB does not appear to affect the level of daily physical activity neither in females nor males.