Longitudinal study of physical activity and sedentary behavior in children

Mindfulness-based intervention for depression and insulin resistance in adolescents: Protocol for BREATHE, a multisite, pilot and feasibility randomized controlled trial

BACKGROUND

Elevated depression symptoms have been associated with higher insulin resistance in adolescents, and consequently, greater risk for type 2 diabetes (T2D). Mindfulness-based intervention (MBI) may be suited for adolescents at risk for T2D given its potential to decrease depression and improve stress-related behavior/physiology underpinning insulin resistance. To prepare for a future multisite efficacy randomized controlled trial, a rigorous, multisite, pilot and feasibility study is needed to test this approach. The current paper describes the design and protocol for a multisite, pilot and feasibility randomized controlled trial of six-week MBI, cognitive-behavioral therapy (CBT), and health education (HealthEd) group interventions, to assess multisite fidelity, feasibility, and acceptability.

METHODS

Participants are N = 120 adolescents ages 12-17, with body mass index (BMI) ≥85th percentile, elevated depression symptoms (20-item Center for Epidemiologic Studies-Depression Scale total score > 20), and family history of diabetes. Enrollment occurs across four United States (US) sites, two in Colorado, one in Washington, D·C., and one in Maryland. Group interventions are delivered virtually by trained psychologists and co-facilitators. Assessments occur at baseline, six-week follow-up, and one-year follow-up.

RESULTS

Primary outcomes are intervention implementation fidelity, based upon expert ratings of audio-recorded sessions (≥80% adherence/competence), and recruitment feasibility, based upon percentage enrollment of eligible youth (≥80%). Secondary outcomes are intervention training fidelity/feasibility/acceptability, recruitment timeframe, and retention/assessment feasibility.

CONCLUSION

Findings will inform optimization of training, recruitment, intervention delivery, retention, and assessment protocols for a multisite, efficacy randomized controlled trial evaluating MBI for decreasing depression and improving insulin resistance in adolescents at risk for developing T2D.

Influence of Growth, Maturation, and Sex on Maximal Power, Force, and Velocity During Overground Sprinting

ABSTRACT

Sudlow, A, Galantine, P, Del Sordo, G, Raymond, J-J, Dalleau, G, Peyrot, N, and Duché, P. Influence of growth, maturation, and sex on maximal power, force, and velocity during overground sprinting. J Strength Cond Res 38(3): 491-500, 2024-In pediatric populations maximal anaerobic power, force, and velocity capabilities are influenced by changes in body dimensions and muscle function. The aim of this study was to investigate the influences of growth, maturation, and sex on short-term anaerobic performance. One hundred forty children pre-, mid-, and postpeak height velocity performed two 30-m sprints concurrently measured using a radar device. Maximal power (Pmax), force (F0), and velocity (v0) were calculated from sprint velocity-time data and normalized using sex-specific, multiplicative, allometric models containing body mass, fat-free mass (FFM), or height, and chronological age. Absolute values for Pmax, F0, and v0 were higher with increasing maturity (p < 0.01; d ≥ 0.96), and boys had greater outputs than girls (p < 0.01; d ≥ 1.19). When Pmax and v0 were scaled all maturity-related and sex-related differences were removed. When F0 was scaled using models excluding age, all maturity-related differences were removed except for the least mature group (p < 0.05; d ≥ 0.88) and boys maintained higher values than girls (p < 0.05; d ≥ 0.92). All maturity-related and sex-related differences were removed when F0 was scaled using models including age. Maturity-related and sex-related variance in Pmax and v0 can be entirely explained when FFM, height, and chronological age are accounted for. Regarding F0, there seems to be a threshold after which the inclusion of age is no longer necessary to account for maturity-related differences. In young prepubertal children, the inclusion of age likely accounts for deficits in neuromuscular capacities and motor skills, which body dimensions cannot account for. Practitioners should focus on eliciting neural adaptations and enhancing motor coordination in prepubertal children to improve anaerobic performance during overground sprinting.

Gender differences in the distribution of children's physical activity: evidence from nine countries

BACKGROUND

Physical activity in childhood is thought to influences health and development. Previous studies have found that boys are typically more active than girls, yet the focus has largely been on differences in average levels or proportions above a threshold rather than the full distribution of activity across all intensities. We thus examined differences in the distribution of physical activity between girls and boys in a multi-national sample of children.

METHODS

We used the harmonised International Children Accelerometry Database (ICAD), including waist-worn accelerometry data from 15,461 individuals (Boys: 48.3%) from 9 countries. Employing Generalised Additive Models of Location, Shape, and Scale (GAMLSS) we investigated gender differences in the distribution of individuals, including comparisons of variability (SD) and average physical activity levels (mean and median) and skewness. We conducted this analysis for each activity intensity (Sedentary, Light, and Moderate-to-Vigorous (MVPA)) and a summary measure (counts per minute (CPM)).

RESULTS

Sizable gender differences in the distribution of activity were found for moderate to vigorous activity and counts per minute, with boys having higher average levels (38% higher mean volumes of MVPA, 20% higher CPM), yet substantially more between-person variability (30% higher standard deviation (SD) for MVPA, 17% higher SD for CPM); boys' distributions were less positively skewed than girls. Conversely, there was little to no difference between girls and boys in the distribution of sedentary or light-intensity activity.

CONCLUSIONS

Inequality in activity between girls and boys was driven by MVPA. The higher mean volumes of MVPA in boys occurred alongside greater variability. This suggests a need to consider the underlying distribution of activity in future research; for example, interventions which target gender inequality in MVPA may inadvertently lead to increased inequality within girls.

Global Accelerometer-derived Physical Activity Levels from Preschoolers to Adolescents: A Multilevel Meta-analysis and Meta-regression

BACKGROUND

Global level physical activity surveillance studies were primarily based on self-report data that could generate inaccurate results.

PURPOSE

To investigate global accelerometer-measured daily moderate to vigorous physical activity (MVPA) changes from preschool age to adolescence as well as gender differences in MVPA while adjusting for the geographic regions and major MVPA cut points.

METHODS

A comprehensive search was conducted through August 2020 that includes 30 databases such as Academic Search Ultimate, Child Development & Adolescent Studies, Education Full Text, ERIC, General Science, PsycINFO, ScienceDirect, and SPORTDiscuss. We included both cross-sectional and longitudinal MVPA tracking studies with daily MVPA being measured by waist-worn accelerometers and determined by either Freedson 3 METs, 4 METs, or Evenson cut points for preschoolers, children, and adolescents.

RESULTS

Researchers analyzed 84 studies reporting on 124 effect sizes with a total of 57,587 participants. The combined data showed significant MVPA differences among various continents of participants (p < .001) or cut points (p < .05-.001) for both preschoolers, children, and adolescents. Globally, when continents and cut points were controlled, individuals' daily MVPA time decreased every year by an average of 7.88, 10.37, and 6.68 min from preschool age to adolescence, preschool age to children, and children to adolescence, respectively. When cut points and continents were controlled, boys had significantly higher daily MVPA than girls for all three age groups (p < .001).

CONCLUSIONS

Globally, individuals' daily MVPA starts to decline dramatically as early as the beginning of preschool age. Early intervention is needed to counteract the high decline rate in MVPA.

Correlates of the Physical Activity Decline during Childhood

PURPOSE

This study aimed to describe longitudinal trends in children's moderate-to-vigorous physical activity (MVPA) and to investigate associations with individual, familial, and school characteristics.

METHODS

A sample of 341 Portuguese children age 5-10 yr (173 girls) from six age cohorts was followed over 3 yr using a mixed-longitudinal design. Physical activity, body mass index (BMI), gross motor coordination, and musculoskeletal fitness were assessed annually. Information on socioeconomic status and school characteristics was collected and analyzed with mixed models.

RESULTS

MVPA shows a similar declining trend in both sexes, but on average, boys exceeded the World Health Organization recommendations of 60 min·d -1 . The best model showed that boys spend, on average, more time in MVPA than girls. Children with lower BMI are less prone to the decline in MVPA, whereas higher levels of musculoskeletal fitness were associated with lower declines in MVPA. Of all school characteristics, only playground dimension was related to MVPA decreasing trajectories.

CONCLUSIONS

MVPA systematically declines from 5 to 10 yr of age in both boys and girls, but boys remained more active than girls across the age range. The best predictors of MVPA decline are sex, BMI, musculoskeletal fitness, and school playground dimension.

The Coronavirus Disease 2019 Pandemic is Associated with a Substantial Rise in Frequency and Severity of Presentation of Youth-Onset Type 2 Diabetes

OBJECTIVES

To evaluate the frequency and severity of new cases of youth-onset type 2 diabetes in the US during the first year of the pandemic compared with the mean of the previous 2 years.

STUDY DESIGN

Multicenter (n = 24 centers), hospital-based, retrospective chart review. Youth aged ≤21 years with newly diagnosed type 2 diabetes between March 2018 and February 2021, body mass index ≥85th percentile, and negative pancreatic autoantibodies were included. Demographic and clinical data, including case numbers and frequency of metabolic decompensation, were compared between groups.

RESULTS

A total of 3113 youth (mean [SD] 14.4 [2.4] years, 50.5% female, 40.4% Hispanic, 32.7% Black, 14.5% non-Hispanic White) were assessed. New cases of type 2 diabetes increased by 77.2% in the year during the pandemic (n = 1463) compared with the mean of the previous 2 years, 2019 (n = 886) and 2018 (n = 765). The likelihood of presenting with metabolic decompensation and severe diabetic ketoacidosis also increased significantly during the pandemic.

CONCLUSIONS

The burden of newly diagnosed youth-onset type 2 diabetes increased significantly during the coronavirus disease 2019 pandemic, resulting in enormous strain on pediatric diabetes health care providers, patients, and families. Whether the increase was caused by coronavirus disease 2019 infection, or just associated with environmental changes and stressors during the pandemic is unclear. Further studies are needed to determine whether this rise is limited to the US and whether it will persist over time.

Day-level associations of physical activity and sedentary time in mother-child dyads across three years: a multi-wave longitudinal study using accelerometers

Understanding associations between mothers' and children's physical activity and sedentary behavior on more fine-grained timescales can provide insights into real-time intervention opportunities. This study examined the extent to which mothers' and their children's device-measured moderate-to-vigorous physical activity (MVPA) and sedentary time (SDT) were associated at the day level during non-school time. Mother-child dyads (N = 193; baseline Mean ages = 40.69 ± 6.11 [mother] and 9.57 ± 0.89 [child] years) provided 3,135 paired days of accelerometry data from six bi-annual waves across three years. Controlling for covariates, multilevel models revealed that mothers' and their children's MVPA and SDT were positively associated at the day level during non-school time, both on weekdays and weekends. During weekdays, the day-level association for SDT was stronger for older than younger children, and the day-level association for MVPA was stronger for boys than girls. Designing family-based interventions targeting school-age children and their mothers during non-school time across the week may be useful for promoting active lifestyles.

Structural model of the relationship between physical activity and students’ quality of life: Mediating role of body mass index and moderating role of gender

Background

As a country’s future leaders and pioneers, University students must live with healthy habits. In order to achieve a healthy lifestyle, Physical activity and Quality of Life can serve as suitable indices to study. The purpose of the study was to clarify how physical activity (PA), Body mass index (BMI) and gender relate to the quality of life (QOL) of students of Medical Sciences University by using a structural equation model.

Methods

The research was a cross-sectional study. The number of participants was 225 students of the University. The participants answered three questionnaires, including Demographic, International Physical Activity Questionnaire (IPAQ short form), and Quality of Life Questionnaire (SF-12), BMI was calculated by anthropometric measures, as well. The Structural equation model (SEM) method was employed. The Fitness of the proposed pattern was measured using the following indexes: chi-square/degree of freedom ratio (CMIN/DF), Normed Fit Index (NFI), comparative fit index (CFI), the goodness of fit index (GFI), and standardized root mean squared residual (SRMR). In the analysis the significant level was considered as P < 0.05.

Results

PA (r = -0.726, P<0.001) and QOL (r = -0.405, P<0.001) have significantly inverse relationship with BMI, whereas the QOL and PA were proven to be positively related (r = 0.357, P<0.001). Moreover, the results signify gender as a moderator in the relationship between PA and QOL (Δχ² (10) = 19.903, P = 0.030) and also the mediatory role of BMI among students. BMI affects the QOL in men (P < 0.001, β = -0.307) more in compare to women women (P = 0.324, β = -0.158).

Conclusion

Study findings supported the research hypothesis. Gender exhibited moderating role in the relationship between PA and QOL, considering the mediating role of BMI.

24-Hour Movement Behaviors in Children with Chronic Disease and Their Healthy Peers: A Case-Control Study

Background: Time spent in 24-h movement behaviors is important to health and wellbeing in childhood, but levels of these behaviors in children with chronic disease are unknown. Methods: A case-control-study included 80 children with chronic disease; 20 with type 1 diabetes mellitus (T1DM), 20 with juvenile idiopathic arthritis (JIA), 20 with congenital heart disease (CHD), 20 with cystic fibrosis (CF); pair-matched individually for age, sex, and timing of measures with 80 healthy children. Habitual time spent in movement behaviors and step counts were all measured with an activPAL accelerometer over 7 days. Comparisons against recommendations and differences between the groups were made. Results: Time spent in physical activity and step counts/day were significantly lower in T1DM and CHD groups compared to controls. Only 20/80 children with chronic disease and 29/80 controls met step count recommendations. Sedentary time was significantly higher in children with CF compared to controls. Time spent asleep was slightly greater in children with chronic disease, significant only for the JIA group. Sleep disruption was consistently greater in those with chronic disease, reaching significance for T1DM, CHD, and CF groups. Conclusions: For some groups of children with chronic disease, 24-h movement behaviors may differ substantially from recommendations, and slightly but systematically from their healthy peers. Optimizing levels of 24-h movement behaviors should confer a number of benefits for child health, development, and wellbeing.

The Influence of Family Sports Attitude on Children's Sports Participation, Screen Time, and Body Mass Index

Background: Children’s physical health is an important resource for a country’s future construction. However, researchers found that the physical fitness of young children around the world has declined during the two decades, from 1992 to 2012. The decline in the physique of young children has caused widespread concern around the world. Children’s main living places are families and kindergartens, so this research explores the impact of family factors on children’s body mass index (BMI) from the perspective of family attitudes, children’s sports participation, and screen time.

Methods: A cross-sectional study was used to conduct a questionnaire survey of children in China. A total of 600 children were investigated, and 589 valid questionnaires were obtained. SPSS21.0 statistical analysis software was used for descriptive analysis, mean comparison, and correlation analysis of the data. AMOS 21.0 was used to construct a structural equation model and carry out path analysis.

Results: (1) There are significant differences in children’s family sports attitude, sports participation, screen time, and BMI with different family structures, and parents’ education levels. (2) Family sports attitude is significantly positively correlated with parents’ education levels and children’s sports participation, and negatively correlated with children’s screen time and BMI. (3) Children’s sports participation and screen time play a chain-mediating role between family sports attitude and children’s BMI, and the role is a complete mediating role. Therefore, family sports attitudes can affect children’s physical health by affecting children’s sports participation and screen time. To promote children’s physical health, we should pay attention to the intervention of family sports attitude. (4) The mediating effects of exercise participation and screen time are similar in different family structures, so the structure of this study can be applied to different family structures.

Conclusions: Children’s family sports attitude, sports participation, and screen time can affect children’s BMI. Children’s screen time and sports participation play a chain-mediating role in the influence of family sports attitudes on the path of children’s BMI. The results of this study will provide a useful reference for teachers and parents to control children’s physical health.

Failure to Launch: Predictors of Unfavourable Physical Activity and Sedentary Behaviour Trajectories from Childhood to Adolescence: The Gateshead Millennium Study

In a previous study based on this cohort, only 15% of the participants belonged to a favourable physical activity/sedentary behaviour trajectory group (characterised by relatively high moderate–vigorous intensity physical activity and relatively low sedentary behaviour across childhood and adolescence). Since this favourable trajectory is protective against obesity, we aimed to identify factors associated with membership of this group. In this longitudinal study, 671 participants were assessed at ages 7, 9, 12 and 15 years. Participants’ demographics, socio-economic status (SES) and physical activity environment such as, sports club participation and commuting school were assessed at ages 7, 9 and 12 and analysed with favourable trajectory membership as an outcome using multinomial logistic regression. Sex (male) and SES (higher) were the non-modifiable factors associated with favourable trajectory group. Of the modifiable factors, commuting to school at age 7, a safe environment to play at age 7 and sports club participation at age 12 were all associated with more than 2.0 times increased probability of being in the most favourable trajectory. Future interventions to promote a favourable trajectory could focus on girls and participants with low SES. Promoting active commuting, safe local spaces to play and sports participation should also help lead to a favourable trajectory for physical activity and sedentary behaviour across childhood and adolescence.

Physical activity recommendation by health care providers to adults with and without functional limitations

Adults with functional limitations are more likely to be physically inactive than those without functional limitations, despite evidence that regular physical activity (PA) slows the progression of functional decline. The health care setting provides an opportunity to communicate with patients about positive behavior changes, including increased PA, but there is little information about provider recommendation for PA to adults with functional limitations. This study investigated health care provider recommendation to increase PA among adults with and without functional limitations. Adults (≥18 years) who participated in the 2016 National Health Interview Survey and reported ≥1 primary care encounter within the previous 12 months were included (unweighted n = 23,540; weighted N = 170,004,764). Receipt of PA recommendation and physical functioning limitations were self-reported. Statistical analyses were weighted to account for complex survey sampling design. One-third (35.88%) of adults received a PA recommendation and 19.71% reported functional limitations. Adults who received a PA recommendation were more likely to have a functional limitation than those who did not (28.64% vs. 14.70%; p < 0.001), even after adjusting for covariates and current activity level (aOR = 1.48; 95% CI:1.33,1.65). PA recommendation for those with functional limitations appeared to increase during middle age and peak for adults aged 65-75 years (57.01%) but declined substantially for adults ≥75 years. Only one-third of adults in the United States received PA recommendations. Health care providers recommended PA to approximately half of adults with functional limitations. Continued efforts to leverage health care encounters for behavior change should be explored, particularly for middle aged and older adults.

Moderate-to-vigorous physical activity and sedentary behavior in children with and without developmental coordination disorder: Associations with fundamental movement skills

BACKGROUND

There is a pandemic of physical inactivity in children. Compared to children with typical development (TD), those with developmental coordination disorder (DCD) are less physically active. Mastery of movement skills such as fundamental movement skills (FMS) are potential correlates of physical activity.

AIMS

To examine the associations of FMS with moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SB) in children with DCD and TD.

METHODS AND PROCEDURES

This cross-sectional study included 172 children with DCD (n = 73; boys = 49) or TD (n = 99; boys = 48) aged 6-10 years. Five components of FMS (running, jumping, throwing, catching, kicking) were assessed using process- and product- oriented approaches using the Test of Gross Motor Development-second edition. The time spent in MVPA and SB was measured using accelerometers.

OUTCOMES AND RESULTS

Children with DCD had significantly poorer performance in FMS proficiency in terms of specific movement patterns (jumping and catching) and outcomes (running, jumping, catching, and kicking) when compared to children with TD. MVPA and SB were significantly associated with certain process-oriented FMS assessments in children, which was moderated by motor coordination status and sex. Movement patterns of catching (odds ratio = 1.686, p < .05) was a significant predictor of children's attainment of the MVPA guideline.

CONCLUSIONS AND IMPLICATIONS

It is important to develop FMS patterns and ball skills in early childhood, particularly for children with DCD, to combat physical inactivity and its related health problems.

An Exploration of Child-Staff Interactions That Promote Physical Activity in Pre-School

A previous study identified a significant association between the average physical activity levels of pre-school staff and children during pre-school hours but did not determine if this association was initiated by pre-school staff or children. The present study aimed to explore the interactions between children and staff to better understand the conditions of such a relationship. Observations using the Environment and Policy Assessment and Observation (EPAO) protocol were carried out in three pre-schools, and a focus-group interview and semiformal interviews were conducted with five pre-school staff in one of the three pre-schools to examine the research question. Both the observations and the interview data revealed that physical activity by pre-school staff initiated physical activity among the children. The findings pointing to the importance of pre-school staff as organizers of the physical activity of children and the willingness of staff to join a physical activity initiated by the children also appear to be important. The findings also indicate that most of the physical activity took place outdoors. The study highlights the importance of pre-school staff as major contributors to the physical activity of pre-school children.

Longitudinal Perspectives on Children's Physical Activity Patterns: "Do Physical Education-Related Factors Matter?"

BACKGROUND

This study examined longitudinal associations of motor competence (MC) and physical activity (PA) enjoyment with moderate to vigorous PA and sedentary behavior among boys and girls aged 10-12 years old. In addition, this study explored the predictive strength of satisfaction of basic psychological needs in physical education (PE) and PA enjoyment.

METHODS

At 3 time points (baseline, +1 y, and +2 y), PA levels, MC, PA enjoyment, satisfaction of basic psychological needs in PE and height and weight of 371 children were measured. Data were analyzed using repeated-measures linear mixed model analyses stratified for gender and adjusted for relevant covariates.

RESULTS

Sedentary behavior decreased over time and was significantly predicted by PA enjoyment in boys and by PA enjoyment and MC in girls. Boys' moderate to vigorous PA decreased over time and was predicted by MC, whereas girls' moderate to vigorous PA remained low, yet stable over time and was predicted by PA enjoyment and MC. Furthermore, children's need for competence and teacher relatedness (girls only) during PE significantly predicted PA enjoyment.

CONCLUSIONS

Children need sufficient and well-designed opportunities to improve their MC and PA enjoyment. PE may be pivotal in advancing PA enjoyment, indicating that PE could have more beneficial effects on PA levels in children, especially in girls.

Executive function capacity links future thinking and exercise intent

OBJECTIVE

Environmental barriers limit exercise in adolescents, but the contribution of cognitive barriers are not as well characterized. Previous findings suggest future thinking may predict exercise intent, which has been linked to health and actual exercise. However, these models may be incomplete as they do not systematically incorporate potential cognitive contributions (e.g., executive function capacity) to exercise intent. This study investigated the possible mediating role of executive function capacity in the relation between future thinking and exercise intent.

METHODS

Data for the mediation models was collected from 101 adolescents aged 11-17 (M = 13.09) in a summer enrichment program. Adolescent participants completed self-report measures including Consideration of Future Consequences Scale (CFCS), Intent to Exercise, and Behavior Rating Inventory of Executive Function, Second Edition (BRIEF-2).

RESULTS

This study found that self-reported executive function capacity mediated the relation between future thinking and exercise intent even when controlling for age and subjective socioeconomic status.

CONCLUSIONS

While some exercise interventions aim to increase future thinking, this study provides support for additional research into how interventions may benefit from targeting executive function capacity directly to increase exercise intent and actual exercise.

Hypertension among South African children in disadvantaged areas and associations with physical activity, fitness, and cardiovascular risk markers: A cross-sectional study

Childhood hypertension drives hypertension in later life; hence, assessing blood pressure in children is an important measure to determine current and future cardiovascular health. There is, however, a paucity of childhood blood pressure data, particularly for sub-Saharan Africa. This study explores blood pressure and associations with age, sex, socioeconomic status, physical activity, fitness, and cardiovascular risk markers. In the 'Disease, Activity and Schoolchildren's Health' (DASH) study, a cross-sectional analysis was conducted in disadvantaged neighbourhoods in the Eastern Cape province of South Africa. Assessments included blood pressure, accelerometer-measured physical activity, physical fitness, and cardiovascular risk markers. The study consisted of 785 children (383 boys, 402 girls, M = 12.4±0.9 years). Overall, 18% of the children were classified as hypertensive, while 20% were either overweight/obese, and almost four out of ten children did not meet global daily physical activity recommendations. Hypertensive children were more likely to be overweight/obese, χ² (2,785) = 14.42, p < 0.01, but only if they did not meet physical activity recommendations, χ² (2,295) = 11.93, p < 0.01. Considering the moderating effect which sufficient activity has on the relationship between hypertension and body weight, more emphasis should be placed on early primary health intervention and education strategies.

Moderate-To-Vigorous Intensity Physical Activity and Sedentary Behaviour across Childhood and Adolescence, and Their Combined Relationship with Obesity Risk: A Multi-Trajectory Analysis

The combined role of objectively assessed moderate-vigorous intensity physical activity (MVPA) and sedentary behaviour (SB) is unclear in obesity prevention. This study aimed to identify latent groups for MVPA and SB trajectories from childhood to adolescence and examine their relationship with obesity risk at adolescence. From the Gateshead Millennium Study, accelerometer-based trajectories of time spent in MVPA and SB at ages 7, 9, 12, and 15 were derived as assigned as the predictor variable. Fat mass index (FMI), using bioelectrical impedance at age 15, was the outcome variable. From 672 children recruited, we identified three distinct multiple trajectory groups for time spent in MVPA and SB. The group with majority membership (54% of the cohort) had high MVPA and low SB at childhood, but MVPA declined and SB increased by age 15. One third of the cohort (31%) belonged to the trajectory with low MVPA and high time spent sedentary throughout. The third trajectory group (15% of the cohort) that had relatively high MVPA and relatively low SB throughout had lower FMI (-1.7, 95% CI (-3.4 to -1.0) kg/m2, p = 0.034) at age 15 compared to the inactive throughout group. High MVPA and low SB trajectories when combined are protective against obesity.

Reconceptualizing and Operationalizing Seefeldt's Proficiency Barrier: Applications and Future Directions

In 1980, Seefeldt introduced the concept of a motor skill "proficiency barrier" that provides a conceptual basis for understanding the importance of a motor skill barrier as it relates to critical public health initiatives. While the intent of Seefeldt's proficiency barrier hypothesis had great potential to advance the field of motor development, the notion of a proficiency barrier was not empirically tested. Instead, this concept lay dormant for several decades. The purpose of this paper was to expand upon Seefeldt's proficiency barrier concept in greater detail by addressing the following questions: (1) what constitutes a motor proficiency barrier? (2) how do we assess/measure the existence of a proficiency barrier? and (3) how do we break through the proficiency barrier in order to maximize the likelihood of participation in health-enhancing levels of physical activity later on in life? We conclude with a future research suggestion to explore the existence of the proficiency barrier.

Disentangling individual, school, and neighborhood effects on screen time among adolescents and young adults in the United States

OBJECTIVES

To examine the association between individual, neighborhood, and school-level influences on individual screen time among adolescents and young adults (AYAs) in the National Longitudinal Study of Adolescent to Adult Health.

METHODS

We classified screen time continuously as self-reported total hours per week of television, videos, and video/computer games at baseline and categorical as extended screen time (≥14 h per week). We fit cross-classified multilevel models (CCMM) to examine to examine the individual-, school- and neighborhood-level demographic and socioeconomic factors associated with screen time. Models were fit using MLwiN with Bayesian estimation procedures.

RESULTS

AYAs reported an average of 22.8 (SD = 19.4) and 21.9 (SD = 20.3) hours of screen time, respectively. At the individual level, younger age, male sex, Black/multiracial race, receipt of public assistance, and lower parental education were associated with higher screen time. At the school level, being out of session (i.e., school and national holidays including summer), having a higher proportion of non-White students, and having a lower proportion of parents with a college education were associated with higher individual screen time.

CONCLUSIONS

We found that individual-level factors most influence youth screen time, with smaller contributions from school factors.

Towards a Functional Approach to the Assessment of Daily Life Physical Activity in Children: Are the PAQ-C and Fitbit Flex-2 Technically Adequate?

Considering the need for functional physical activity (PA) measures in PA settings, this study sought to determine the technical adequacy of the Physical Activity Questionnaire for Older Children (PAQ-C) and the Fitbit Flex-2, two instruments with promising features for wide use, using the Actigraph GT3X+ accelerometer as the criterion reference. A total of 218 Greek children (94 boys, 124 girls; mean age = 10.99 ± 1.52 years) volunteered to join in. Participants wore the PA trackers for seven days and completed the PAQ-C. Moreover, a sub-group (n = 60) recompleted the PAQ-C after a week. Results revealed acceptable internal consistency and excellent test-retest reliability for the PAQ-C. Regarding concurrent validity, weak to moderate correlations with PA parameters recorded by the GT3X+ were revealed for the total PAQ-C and were excellent for the Flex-2, while a Bland-Altman plot indicated good agreement. Finally, in alignment with relevant literature, significant gender, but no age, differences were found in participants' PA records in all the tools applied. The above results support the use of the PAQ-C and the Fitbit Flex-2 in children. Considering that they shed light into different parameters of children's habitual PA, their combined utilisation, providing comprehensive information, is strongly recommended.

The Relationship Between Physical Activity and Inhibition in Children With and Without Motor Impairments

BACKGROUND

To examine the relationship between physical activity (PA) and inhibition in boys and girls with motor impairments compared with children with typical development.

METHODS

The participants were 58 (26 motor impairments and 32 typical development) children aged 7-12 years who met the inclusion criteria. PA was assessed using accelerometers for 7 consecutive days. The time spent in PA of different intensity levels (light, moderate, and vigorous) were analyzed for weekdays and weekends. Using a visuospatial attention paradigm, inhibition was evaluated by the difference in reaction time between invalid and valid cue conditions. Generalized linear mixed models were used to determine the associations of inhibition with PA and motor ability by sex.

RESULTS

Boys and children with typical development had shorter reaction times in inhibition than girls (P < .001) and children with motor impairments (P < .05), respectively. Motor ability (b = 189.98) and vigorous PA on weekdays (b = -43.18) were significant predictors of inhibition in girls only.

CONCLUSIONS

The results indicate a positive relationship between vigorous PA (on weekdays) and inhibition in children (girls), moderated by sex and motor ability. Effective interventions that promote vigorous PA for children both in and out of school should be designed to foster their executive function development.

Parents' perceptions and concerns about physical activity participation among adolescents with autism spectrum disorder

The parents of adolescents with autism spectrum disorder have a vital and proactive role in encouraging healthy physical activity habits, and they possess important knowledge about the adolescents’ needs when it comes to enhancing participation in physical activity. But promoting healthy physical activity habits in adolescents can be difficult. The purpose of this study was thus to describe parents’ perceptions of their adolescent child’s participation in physical activity and to describe the parental role in promoting such participation. Twenty-eight parents of adolescents aged 12–16 years with autism spectrum disorder were interviewed. The interviews were analyzed using an inductive content analysis approach. The parents described how challenging participation in physical activities could be for their adolescents. Despite this, they wanted to see their children participate more in physical activity but found the promotion of physical activity to be an overwhelming task that was difficult to cope with on their own. The results reveal a need for support and collaborative efforts among different actors to give these issues increased priority in order to promote the adolescents’ physical activity participation.

The Influence of Role Models on the Sedentary Behaviour Patterns of Primary School-Aged Children and Associations with Psychosocial Aspects of Health

BACKGROUND

High levels of sedentary behaviour (SB) are associated with poor health outcomes in children, but the effects on mental health are less clear. This study explored the relationship between SB and psychosocial aspects of health in children, and what influence key role models, including parents and schoolteachers, have on the SB levels of children.

METHODS

Physical activity (PA) and SB were measured using accelerometery in 101 children, 113 parents and 9 teachers. Children were aged 9 or 10 years old and in fourth grade. Child psychosocial outcomes were assessed using the Rosenberg Self-Esteem Scale and the Strengths and Difficulties Questionnaire.

RESULTS

Children engaged in a high volume of SB (9.6 h/day) but interrupted SB often. They accumulated less than 11,000 steps per day, and thus, many may not meet the recommended daily levels of PA. No associations were found between child SB and teacher SB during the school day or child SB and parent SB during the after-school period. No association was found between SB and self-esteem, although children with a higher body mass index had a higher number of emotional and behavioural difficulties.

CONCLUSIONS

Although there was no indication that children's SB was linked to that of parents and teachers, or that SB was associated with self-esteem or behavioural problems, school children were highly sedentary and insufficiently physically active. Therefore, there is a need to explore school practices and curriculum delivery methods, as well as school and home environments, to reduce the volume of SB children engage in.

Changes in physical activity and sedentary time during adolescence: Gender differences during weekdays and weekend days

OBJECTIVES

The objective of this study was to determine the gender-specific and time-segmented changes in accelerometer measured physical activity (PA) and sedentary time (ST) during adolescence.

METHODS

The study population (N = 970) consisted of children from nine schools throughout Finland. At the baseline, the children were in grades 4-7 (ages 10-13). Five times during the two-year follow-up period, hip-worn accelerometers (ActiGraph GT3X+) were deployed for seven consecutive days in order to monitor the pupils' PA. The daily time spent in vigorous (VPA), moderate to vigorous (MVPA), and light physical activity(LPA), as well as sedentary time(ST), were assessed.

RESULTS

Significant gender differences were observed in terms of the changes in MVPA and ST during the follow-up period. The total MVPA declined significantly in boys (by 2.2min/day/year from 60 min/d at baseline) but not in girls (49 min/d at baseline). The total ST increased both in boys (by 20.7%-points/y) and in girls (by 16.1%-points/y, P < .001). However, when we compared the results during the weekdays and weekend days separately, we observed that the declines in MVPA and increases in ST were greater in boys than in girls during the weekend days.

CONCLUSION

A greater decrease in PA and a greater increase in ST during adolescence were observed among boys than among girls, especially during weekend days. In order to diminish these unfavorable behavioral changes during adolescence, we encourage the separate tailoring of interventions for boys and girls and for weekdays and weekends.

Social inequalities in traditional and emerging screen devices among Portuguese children: a cross-sectional study

BACKGROUND

Children are often exposed to too much screen time but few studies have explored the use of old and new digital media among young children. This study assesses screen time, including traditional and mobile devices, in pre-school and elementary school-aged children, according to their gender, age, and socioeconomic position (SEP).

METHODS

A total of 8430 children (3 to 10 years; 50.8% boys) from the north, center and south-central Portugal were included in the present study. Data was collected by a parental questionnaire during 2016/2017. Children's screen time (by media device, weekdays and at the weekend; calculated by mean minutes per day) were reported by parents. Analysis were carried to compare screen time by children's age, gender and family SEP (classified using father's educational degree).

RESULTS

Daily screen time was high both in children aged 3 to 5 and 6 to 10 years - 154 min/day (95% CI: 149.51-158.91) and 200.79 min/day (95% CI: 197.08-204.50), respectively - and the majority of children, independently of their gender, exceed the recommended 2 h/day of screen viewing. Children are still primarily engaging in screen time through television but the use of mobile devices, particularly tablets, were already high among 3 year-old children and increased with age. SEP was a negative predictor of screen time in the linear regression analysis, including after adjustment.

CONCLUSIONS

Considering the negative health impacts of excessive screen time, recognizing subgroups at risk of excessive screen time and identifying how each device is used according to age is fundamental to enable appropriate future interventions. The screen time in children aged 3-10 years is longer than the recommended, particularly among boys and in those children from lower SEP. Parents and policymakers should have in mind that children spend most of their screen time watching television but mobile devices are becoming extremely popular starting at a young age.

Using Virtual Agents and Activity Monitors to Autonomously Track and Assess Self-Determined Physical Activity Among Young Children: A 6-Week Feasibility Field Study

The majority of youth fail to get the recommended amount of physical activity (PA), and there is a precipitous decline in PA among children as they get older. Guided by self-determination theory and social cognitive theory, we designed an interactive, mixed reality PA intervention for 6-10-year-old children. Capitalizing on the features of consumer-grade interactive communication technologies, the intervention features a kiosk-based system that houses a virtual agent programmed to encourage children to set self-determined PA goals. This intervention aims to resolve many practical challenges in designing and administering a personalized, intrinsically motivated PA intervention for this age group. We pilot tested the feasibility of this kiosk across 6 weeks with n = 42 child/parent dyads. The kiosk tracked and logged children's daily PA and engagement with the intervention without having to rely on human reporting, provided tailored evaluation and feedback whenever children requested it, informed parents about their child's PA progress, and employed a virtual agent (a dog) to offer social support to children. The virtual agent prompted users to set PA goals, and as children met these goals over time, their personalized dog became happier, more fit, and better at tricks. Each time a child engaged with the kiosk the system automatically sent a text message to his/her parent with details about the child's PA progress. The current study demonstrated the kiosk's feasibility in the field over 6 weeks, illustrating the potential of using interactive technologies as tools for disseminating self-sufficient, and truly self-determined health interventions for children at scale.

Sedentary behavior patterns and adiposity in children: a study based on compositional data analysis

BACKGROUND

Between-person differences in sedentary patterns should be considered to understand the role of sedentary behavior (SB) in the development of childhood obesity. This study took a novel approach based on compositional data analysis to examine associations between SB patterns and adiposity and investigate differences in adiposity associated with time reallocation between time spent in sedentary bouts of different duration and physical activity.

METHODS

An analysis of cross-sectional data was performed in 425 children aged 7-12 years (58% girls). Waking behaviors were assessed using ActiGraph GT3X accelerometer for seven consecutive days. Multi-frequency bioimpedance measurement was used to determine adiposity. Compositional regression models with robust estimators were used to analyze associations between sedentary patterns and adiposity markers. To examine differences in adiposity associated with time reallocation, we used the compositional isotemporal substitution model.

RESULTS

Significantly higher fat mass percentage (FM%; β_ilr1 = 0.18; 95% CI: 0.01, 0.34; p = 0.040) and visceral adipose tissue (VAT; β_ilr1 = 0.37; 95% CI: 0.03, 0.71; p = 0.034) were associated with time spent in middle sedentary bouts in duration of 10-29 min (relative to remaining behaviors). No significant associations were found for short (< 10 min) and long sedentary bouts (≥30 min). Substituting the time spent in total SB with moderate-to-vigorous physical activity (MVPA) was associated with a decrease in VAT. Substituting 1 h/week of the time spent in middle sedentary bouts with MVPA was associated with 2.9% (95% CI: 1.2, 4.6), 3.4% (95% CI: 1.2, 5.5), and 6.1% (95% CI: 2.9, 9.2) lower FM%, fat mass index, and VAT, respectively. Moreover, substituting 2 h/week of time spent in middle sedentary bouts with short sedentary bouts was associated with 3.5% (95% CI: 0.02, 6.9) lower FM%.

CONCLUSIONS

Our findings suggest that adiposity status could be improved by increasing MVPA at the expense of time spent in middle sedentary bouts. Some benefits to adiposity may also be expected from replacing middle sedentary bouts with short sedentary bouts, that is, by taking standing or activity breaks more often. These findings may help design more effective interventions to prevent and control childhood obesity.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents

Background

Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe.

Methods

Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2–18 years) from 18 different European countries.

Results

Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age.

Conclusions

Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

How physically literate are children today? A baseline assessment of Greek children 8-12 years of age

Developing Physical Literacy (PL) in children is considered a promising concept for establishing active lifestyle habits; yet research evidence is scarce. This study aimed at comprehensively assessing PL in 8-12-year-old Greek children. For that purpose, the Canadian Assessment of Physical Literacy (CAPL-2) was administered to 715 children (M age = 10.2, SD = 1.3 years). Analyses of variance were applied on participants' total, domain and individual measures scores, examining potential gender and age differences; whereas, participants' classification and proportion across CAPL-2 interpretive categories were computed. Results revealed that there were no practically important differences (η² < .14) between boys and girls or younger (grades 3 & 4) and older children (grades 5 & 6). Greek children presented insufficient levels of PL (their total score classified them into "progressing" PL level). CAPL-2 domains and individual measures scores showed that participants were highly motivated and felt confident to participate in physical activity (PA); however, they exhibited low PA as well as unsatisfactory physical competence, knowledge, and understanding to value and take responsibility for engagement in PA. Although further research is needed for a comprehensive picture of PL correlates, our findings highlight the need for providing Greek children with ample opportunities to enhance their PL.

Associations of Sitting Behavior Patterns With Cardiometabolic Risk in Children: The Sit Less for Health Cross-Sectional Study

BACKGROUND

The objective of this study was to investigate the associations between sedentary behavior patterns and cardiometabolic risk in children using a monitor that accurately distinguishes between different postures.

METHODS

In this cross-sectional study, 118 children (67 girls) aged 11-12 years had adiposity, blood pressure, lipids, and glucose measured, and then they wore an activPAL device to record sitting, standing, and stepping for 7 consecutive days. Data were analyzed using multiple linear regression.

RESULTS

After adjustment for potential confounders and moderate to vigorous physical activity, the number of breaks in sitting was significantly negatively associated with adiposity (standardized β ≥ -0.546; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.415; P ≤ .01). Time in prolonged sitting bouts was significantly negatively associated with adiposity (β ≥ -0.577; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.432; P ≤ .05). Standing time was significantly negatively associated with adiposity (β ≥ -0.270; P ≤ .05) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.312; P ≤ .05).

CONCLUSIONS

This study suggests that increasing the number of breaks in sitting and increasing standing time are beneficially associated with cardiometabolic risk and should be considered in health promotion interventions in children.

Differences in the Physical Activity, Sedentary Time, and BMI of Finnish Grade 5 Students

BACKGROUND

This study examined the distribution of objectively measured physical activity (PA) and sedentary time of fifth-grade students during school, leisure time, and physical education (PE) classes. Demographic, anthropometric, and PA data were collected from 17 representative Finnish schools.

METHODS

To estimate the PA and sedentary time, participants (N = 592) wore wGT3X-BT ActiGraphs for 7 consecutive days. Comparisons were made between genders and different BMI groups.

RESULTS

From the study sample, 43.7% met the moderate to vigorous PA (MVPA) guidelines. Participants spent 62.2% of the day sedentary and 8.2% in moderate and vigorous activities. Boys performed more MVPA than girls, and girls were more sedentary during school days. Boys had more MVPA than girls in leisure time, but there were no differences in sedentary time. However, an examination of PA assessed during PE classes revealed no differences between boys and girls. Normal-weight boys engaged in more MVPA than overweight and obese boys. No differences were found for girls.

CONCLUSIONS

The PE levels differ between different BMI groups in leisure time and during school but not during PE lessons. PA for overweight children should be targeted and compulsory PE time should be increased to achieve the PA guidelines.

Low Childhood Nature Exposure is Associated with Worse Mental Health in Adulthood

Exposure to natural outdoor environments (NOE) is associated with health benefits; however, evidence on the impact of NOE exposure during childhood on mental health (MH) and vitality in adulthood is scarce. This study was based on questionnaire data collected from 3585 participants, aged 18-75, in the PHENOTYPE project (2013) in four European cities. Mixed models were used to investigate associations between childhood NOE exposure and (i) MH; (ii) vitality (perceived level of energy and fatigue); and (iii) potential mediation by perceived amount, use, satisfaction, importance of NOE, and residential surrounding greenness, using pooled and city-level data. Adults with low levels of childhood NOE exposure had, when compared to adults with high levels of childhood NOE exposure, significantly worse mental health (coef. -4.13; 95% CI -5.52, -2.74). Childhood NOE exposure was not associated with vitality. Low levels of childhood NOE exposure were associated with lower importance of NOE (OR 0.81; 95% CI 0.66, 0.98) in adulthood. The association with perceived amount of NOE differed between cities. We found no evidence for mediation. Childhood NOE exposure might be associated with mental well-being in adulthood. Further studies are needed to confirm these findings and to identify mechanisms underlying long-term benefits of childhood NOE exposure.

Tracking of objective physical activity and physical fitness in Japanese children

Objective

The purpose of this study was to examine the tracking of objective physical activity and physical fitness from childhood to adolescence in Japanese children. The longitudinal study comprised 368 participants (aged 9–10 years) in 2008, and the study involved 134 participants (aged 13–14 years, a dropout rate of 63.6%) in 2011. After excluding participants with missing data, a total of 111 participants (46 boys and 65 girls) were available for study. Step counts and moderate-to-vigorous physical activity (MVPA) were measured using a uniaxial accelerometer. Physical fitness was assessed using the following tests: hand grip, sit-ups, sit and reach, side-to-side steps, 20-m shuttle run, 50-m dash, standing broad jump and ball throwing.

Results

In boys, there was a significant correlation between objective physical activity and all physical fitness tests at baseline and follow-up. In girls, although there was no significant correlation between objective physical activity at baseline and follow-up, all physical fitness tests at baseline and follow-up were significantly correlated. In conclusion, moderate tracking was shown in objective physical activity of boys from childhood to adolescence. In addition, moderate to high tracking was shown in physical fitness of both sexes from childhood to adolescence.

The effect of sport for LIFE: all island in children from low socio-economic status: a clustered randomized controlled trial

BACKGROUND

School-based interventions offer the opportunity to increase physical activity, health-related quality of life (HRQOL) and nutritional behaviours, yet methodological limitations hinder current research, particularly among under-represented children from low socio-economic status (SES). The aim was to determine the effect of a 12-week physical activity programme, Sport for LIFE: All Island (SFL:AI), on physical activity levels, HRQOL, and nutritional attitudes and behaviours in children of low SES across the island of Ireland.

METHODS

A 2 (groups) × 4 (data collection points) clustered randomised controlled trial was conducted comprising an intervention group who received SFL:AI for 12 weeks, and a waiting-list control condition. In total 740 children (381 boys, 359 girls) aged 8-9 years (mean = 8.7; SD = .50) from 27 schools across four regions of Ireland (Ulster, Leinster, Connacht and Munster) took part. Physical activity was measured by accelerometers, and children completed a validated questionnaire at baseline, mid (i.e. 6-weeks), post-intervention (i.e. 12 weeks) and follow-up (i.e. 3 months post-intervention).

RESULTS

No significant interaction effects for the intervention were found on any of the study outcomes. Main effects were reported for physical well-being, parental relations and autonomy and financial resources, as well as sweetened beverages, environment and intake, and attitude to vegetables. However, these changes were not statistically attributable to the intervention.

CONCLUSIONS

It remains unclear if school-based physical activity interventions can improve HRQOL through physical activity with children from low SES. Logistical and methodological considerations are outlined to explore the null effect of the programme, and to provide suggestions for future research and practice.

TRIAL REGISTRATION

Trial registration number: ISRCTN76261698 . Name of registry: ICRCTN. Date of registration: 23/08/2017. Date of enrolment: September 2014.

Detection of Pediatric Upper Extremity Motor Activity and Deficits With Accelerometry

IMPORTANCE

Affordable, quantitative methods to screen children for developmental delays are needed. Motor milestones can be an indicator of developmental delay and may be used to track developmental progress. Accelerometry offers a way to gather real-world information about pediatric motor behavior.

OBJECTIVE

To develop a referent cohort of pediatric accelerometry from bilateral upper extremities (UEs) and determine whether movement can accurately distinguish those with and without motor deficits.

DESIGN, SETTING, AND PARTICIPANTS

Children aged 0 to 17 years participated in a prospective cohort from December 8, 2014, to December 29, 2017. Children were recruited from Ranken Jordan Pediatric Bridge Hospital, Maryland Heights, Missouri, and Washington University School of Medicine in St Louis, St Louis, Missouri. Typically developing children were included as a referent cohort if they had no history of motor or neurological deficit; consecutive sampling and matching ensured equal representation of sex and age. Children with diagnosed asymmetric motor deficits were included in the motor impaired cohort.

EXPOSURES

Bilateral UE motor activity was measured using wrist-worn accelerometers for a total of 100 hours in 25-hour increments.

MAIN OUTCOMES AND MEASURES

To characterize bilateral UE motor activity in a referent cohort for the purpose of detecting irregularities in the future, total activity and the use ratio between UEs were used to describe typically developing children. Asymmetric impairment was classified using the mono-arm use index (MAUI) and bilateral-arm use index (BAUI) to quantify the acceleration of unilateral movements.

RESULTS

A total of 216 children enrolled, and 185 children were included in analysis. Of these, 156 were typically developing, with mean (SD) age 9.1 (5.1) years and 81 boys (52.0%). There were 29 children in the motor impaired cohort, with mean (SD) age 7.4 (4.4) years and 16 boys (55.2%). The combined MAUI and BAUI (mean [SD], 0.86 [0.005] and use ratio (mean [SD], 0.90 [0.008]) had similar F1 values. The area under the curve was also similar between the combined MAUI and BAUI (mean [SD], 0.98 [0.004]) and the use ratio (mean [SD], 0.98 [0.004]).

CONCLUSIONS AND RELEVANCE

Bilateral UE movement as measured with accelerometry may provide a meaningful metric of real-world motor behavior across childhood. Screening in early childhood remains a challenge; MAUI may provide an effective method for clinicians to measure and visualize real-world motor behavior in children at risk for asymmetrical deficits.

Non-linear longitudinal associations between moderate-to-vigorous physical activity and adiposity across the adiposity distribution during childhood and adolescence: Gateshead Millennium Study

OBJECTIVE

Insufficient moderate-to-vigorous intensity physical activity (MVPA) is harmful for youth; however, the evidence for differential effects by weight status is limited. The study aimed to examine associations between MVPA and adiposity by weight status across childhood and adolescence.

METHODS

Participants were from the Gateshead Millennium Study. Physical activity and body composition measures were taken at age 7 y (n = 502; measures taken between October 2006 and December 2007), 9 y (n = 506; October 2008-September 2009), 12 y (n = 420; October 2011-September 2012), and 15 y (n = 306; September 2014-September 2015). Participants wore an ActiGraph GT1M and epochs were classified as MVPA when accelerometer counts were ≥574 counts/15 s. Weight and height were measured using standardized methods and fat mass using bioelectrical impedance. Associations between MVPA and changes in BMI and FMI were examined by weight status using quantile regression.

RESULTS

Higher MVPA was associated with lower FMI for the 25th, 50th, 75th, and 90th percentile and lower BMI at the 50th, 75th, and 90th percentile, independent of accelerometer wear time, sex, and sedentary time. The association between MVPA and change in adiposity was stronger in the higher than lower FMI and BMI percentiles (e.g., 1 h/day more MVPA was associated with a 1.5 kg/m2 and 2.7 kg/m2 lower FMI at the 50th and 90th FMI percentiles, respectively).

CONCLUSIONS

The effect of MVPA on adiposity in the higher adiposity percentiles is stronger than reported to date. Given overweight and obese children are the highest risk group for later obesity, targeting MVPA might be a particularly effective obesity prevention strategy.

Points-Based Reward Systems in Gamification Impact Children's Physical Activity Strategies and Psychological Needs

Gamification is an increasingly popular form of health intervention but its efficacy remains elusive due to a lack of clarity in its conceptualization and operationalization. This study aimed to isolate and determine the direct causal effect of one of the most popular game elements used in gamified interventions, the points-based reward system, on physical activity (PA) in children. A 72-hour field study with children aged 9 to 13 ( N = 67) was conducted using a digital PA intervention featuring a virtual dog, with and without a points-based reward system. PA was assessed with an activity monitor, and overall PA, three levels of PA intensity, and PA strategies during the 3-day intervention were measured. Guided by self-determination theory, the impact of the points-based reward system on children's basic psychological needs was also investigated. Results indicated that the points-based reward system briefly increased PA engagement but did not significantly affect overall PA over time. When given equal number of points regardless of intensity, children approached the PA intervention strategically by engaging in significantly more light intensity and significantly less vigorous intensity PA than children who did not receive points. Results also suggested that the points-based reward system might promote perceptions of relatedness with the virtual agent featured in the gamified intervention.

Like father, like son. Physical Activity, Dietary Intake, and Media Consumption in Pre-School-Aged Children

An imbalance between energy input and energy needs contributes to the growing incidence of overweight children. Pre-schoolers normally like to move, but even at this young age, they are already affected by a lack of physical activity and a high amount of screen time. Media consumption contributes to unhealthy diets and extends the length of time spent sitting. Longer periods of sitting are, independent of the level of activity, seen as a risk factor for the development of obesity. In the present study, 160 pre-schoolers and their parents (128 mothers, 121 fathers) were examined. The results show deviations from actual recommendations regarding physical activity, time spent sitting, dietary intake, and media consumption. Increased screen time was associated with a higher weight status among pre-school-aged children. To provide a healthy upbringing, prevention and intervention measures should be implemented on a behavioral and relational level.

Physical Activity and Sedentary Behavior From 6 to 11 Years

: media-1vid110.1542/5849572910001PEDS-VA_2018-0994Video Abstract OBJECTIVES: Physical activity (PA) is presumed to decline during childhood and adolescence, but only few long-term studies about PA development during this period of life exist. We assessed PA and sedentary behavior (SB) over a 5-year period to gain a better understanding of the extent of change in activity and potential influencing factors.

METHODS

PA and SB of 600 children from the Childhood Obesity Project were objectively measured with the SenseWear Armband 2 at the ages of 6, 8, and 11 years, resulting in 1254 observations. Longitudinal changes of total PA, moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), and SB were modeled with mixed-effects models.

RESULTS

Total PA revealed a significant quadratic decline with age (P < .001), resulting in a change of total PA by -75.3 minutes per day from 6 to 11 years. LPA linearly declined (P < .001) by 44.6 minutes per day, MVPA quadratically declined (P < .001) by an overall 30.7 minutes, whereas SB increased significantly (+107 minutes; P = .001). Boys showed a steeper decline in LPA (P = .003) and MVPA (P < .001) than did girls. Higher fat mass index and BMI z scores were associated with lower levels of total PA and MVPA and higher levels of SB (all P < .001).

CONCLUSIONS

We showed that PA decreased, and SB increased in earlier years than previously thought. MVPA remained relatively stable until 8 years, but revealed a drop-off at 11 years, identifying this period as a crucial time for intervention.

Screen time and moderate-to-vigorous physical activity changes and displacement in adolescence: A prospective cohort study

BACKGROUND

This paper determines longitudinal changes in the time Spanish adolescents devote to moderate-to-vigorous physical activity (MVPA) and screen media activity (SMA). Moreover, it examines the displacement hypothesis between time spent on SMA and MVPA.

METHODS

A cohort of 755 adolescents participated in a prospective cohort study over a three-year period. Repeated measures ANOVA to highlight interaction effects among all variables and Structural Equation Modeling (SEM) techniques were employed.

RESULTS

Age and gender-related variations in longitudinal changes in time spent on MVPA and SMA evolved in the inverse direction (decreased on MVPA/increased on SMA) according to the ANOVA. The potential displacement between time spent on SMA and MVPA from Wave I to Wave II was analysed via SEM. The first model, estimated in the overall sample, showed no evidence for the displacement hypothesis. Subsequently, a multigroup sequence of panel models was performed and a partial displacement was observed only in boys. Hence, boys who spent more time on SMA were more likely to devote less time to MVPA three years later.

CONCLUSION

This study confirms the opposite trend on the time spent on MVPA and SMA over a three-year period, being clearly higher in SMA. Further SEM analyses reveal a deferred displacement hypothesis between SMA and MVPA only in boys. This partial gendered displacement may be linked to the different uses adolescents make of screen media. The incursion of new technological devices (smartphones or tablets) and their wide range of possibilities for social networking or gaming could explain this displacement.

Design of a randomized controlled trial to decrease depression and improve insulin sensitivity in adolescents: Mood and INsulin sensitivity to prevent Diabetes (MIND)

BACKGROUND

Depressive symptoms often manifest in adolescence and predict worsening insulin sensitivity, a key precursor in the path to β-cell failure and type 2 diabetes (T2D).

OBJECTIVE

To assess the efficacy of a six-week cognitive-behavioral group versus six-week health education group for improving insulin sensitivity and preserving β-cell function in adolescent girls at-risk for T2D with depressive symptoms and evaluate mechanisms underlying the association between depression and insulin dynamics.

DESIGN

Randomized controlled trial of N = 150 12-17-year-old girls with overweight/obesity (body mass index [BMI; kg/m2] ≥85th percentile), elevated depressive symptoms (Center for Epidemiologic Studies-Depression Scale [CES-D] total score > 20), and diabetes family history.

METHODS

Girls at-risk for T2D with elevated depressive symptoms are recruited from the Denver-metropolitan area and randomized to participate in one of two six-week interventions. The cognitive-behavioral group is a depression prevention program involving psycho-education, restructuring negative thoughts, and behavioral activation. The health education group is a didactic control that provides knowledge about healthy living. Participants are assessed at baseline, immediate post-intervention, and one-year follow-up. Primary outcomes are insulin sensitivity and β-cell function from oral glucose tolerance tests. Secondary outcomes are disinhibited eating, physical activity, sleep, and cortisol.

SUMMARY

Results from this adequately powered randomized controlled trial will determine whether decreasing depressive symptoms with a behavioral health program preventatively alters insulin sensitivity and β-cell function trajectories in adolescents at-risk for T2D. Results from the MIND Project will add to knowledge of the contribution of depressive symptoms to T2D risk.

Bidirectional Associations Between Adiposity, Sedentary Behavior, and Physical Activity: A Longitudinal Study in Children

BACKGROUND

Previous studies have reported on the associations between obesity and sedentary behavior (SB) or physical activity (PA) in children. This study examined longitudinal and bidirectional associations between adiposity and SB and PA in children.

METHODS

Participants were 356 children in England. PA was measured at 7 and 9 years of age using accelerometry. Outcome and exposures were time in SB and PAs and concurrent body mass index z score and fat index (FI).

RESULTS

Adiposity at baseline was positively associated with changes in SB (β = 0.975 for FI) and negatively associated with changes in moderate to vigorous PA (β = -0.285 for body mass index z score, β = -0.607 for FI), vigorous PA (β = -0.095 for FI), and total PA (β = -48.675 for FI), but not vice versa. The changes in SB, moderate to vigorous PA, and total PA for children with overweight/obesity were significantly more adverse than those for children with healthy weight.

CONCLUSIONS

A high body mass index z score or high body fatness at baseline was associated with lower moderate to vigorous PA and vigorous PA after 2 years, but not vice versa, which suggests that in this cohort adiposity influenced PA and SB, but the associations between adiposity and SB or PA were not bidirectional.

Social Status and Adolescent Physical Activity: Expanding the Insurance Hypothesis to Incorporate Energy Expenditure

Low social status (SS) is a determinant of poor health status and is associated with increased disease burden. Obesity affects 20.6% of American adolescents, most of whom are from low-SS families. Contributors to the development of obesity among adolescents include sedentary behavior and low levels of physical activity. Environmental determinants-infrastructure, policy, and social relationships-influence engagement in physical activity and are affected by SS. Significant declines in physical activity have been documented during adolescence, and adolescents of low SS engage in significantly less physical activity per week than those with high SS. This article briefly reviews the literature on the relationship between SS and physical activity in adolescents and introduces a proposed biological mechanism that may explain that relationship. Characterizing the effects that SS can have on physical activity may help tailor clinical interventions and public health campaigns seeking to improve adolescent physical activity and weight management, thus increasing their effectiveness. This may be particularly beneficial for underserved populations.

"Oh oobe doo, I wanna be like you" associations between physical activity of preschool staff and preschool children

OBJECTIVE

Physical activity contributes to prevent serious diseases and ailments, and previous research indicates that lifestyle habits are likely to track from early childhood to adulthood. 90% of Norwegian children aged 1-5 are enrolled in preschools, and preschool staff can play an important role in children's activity levels. This study's aim was to identify whether any associations exist between preschool staff's characteristics (initiative, participation, attitudes, and activity levels) and children's activity in preschool.

METHOD

289 children aged 4-6 and 72 preschool staff from 13 randomly selected preschools in a region of Nord-Troendelag, Norway, were enrolled in the study. All participants wore an Actigraph accelerometer for seven consecutive days. Questionnaires were also utilized to identify correlates between preschool staff's attitudes and initiative in relation to children's physical activity, in addition to their participation in children's physical activity. A multilevel analysis, the linear mixed model (LMM), was used to elucidate associations between preschool staff and children's activity levels.

RESULTS

A significant association was found between preschool staff's average activity levels during preschool hours and children's corresponding activity levels during preschool hours (t = 2.57; p = 0.021; f2 = 0.013). There were, however, no significant associations identified between the attitudes (t = -0.44; p = 0.67), initiative (t = -0.14; p = 0.89), and participation (t = 0.66; p = 0.52) variables among preschool staff and children's activity levels during preschool hours.

CONCLUSION

The study demonstrated that a significant association exists between preschool staff's aggregated activity levels and 4-6-year-olds' individual activity levels. However, an observational study is requisite in order to determine whether the association is based on preschool staff's impact on children's physical activity or if it is the children that affect the preschool staff's activity levels, or a combination thereof.

Longitudinal changes in vigorous intensity physical activity from childhood to adolescence: Gateshead Millennium Study

OBJECTIVE

The aims of our study were to quantify levels and investigate sex-specific changes and trajectories in VPA longitudinally from age 7 to 15 years.

DESIGN

Longitudinal observational study.

METHODS

Participants were part of the Gateshead Millennium Study. Measures were taken at age 7 (n=507), 9 (n=510), 12 (n=425) and 15 years (n=310). Vigorous physical activity was quantified objectively using ActiGraph GT1M accelerometers over 5-7days at the four time-points. Multilevel linear spline random-effects model and trajectory analysis to identify sub-groups were performed.

RESULTS

In boys, average VPA declined across childhood followed by an increase at adolescence, while in girls, average VPA declined across the 8-year study period. In boys, daily VPA decreased from 9-12 years (1.70minutes/year) and increased from 12-15 years (1.99minutes/year) (all p <0.05). In girls daily VPA decreased from 7-9 years (1.70minutes/year) (p <0.05). Three VPA trajectories were identified which differed between the sexes. In boys, one group decreased from an initial relatively high level, one group, initially relatively low, increased, whereas the third one was stable over the 8-year period. In girls, all three groups declined from baseline.

CONCLUSIONS

Marked sex and age-specific trajectories in VPA change were observed. These novel findings should help sports and exercise medicine specialists, as well as policy makers, in their effort to maintain or increase VPA in childhood and adolescence.

Relationship Among Changes in Sedentary Time, Physical Activity, and Body Mass Index in Young Schoolchildren: A 3-Year Longitudinal Study

PURPOSES

To examine the association between sedentary time (ST) and light physical activity (LPA), moderate- to vigorous-intensity physical activity (MVPA), and body mass index (BMI), and to track these behaviors over a 3-year follow-up in young schoolchildren.

METHODS

The final sample was 64 children (female: n = 36 or 56.3%), enrolled in schools in Porto, Portugal. Height and mass of children were measured by standard methods, and BMI was then calculated. ST, LPA, and MVPA were measured by accelerometer. Changes (Δ) and relative changes (Δ%) between 2009/2010 and 2012/2013 of ST, LPA, MVPA, and BMI were computed. Multiple linear regression analyses were fit to predict Δ%ST (outcome variable), by Δ%LPA, Δ%MVPA, and Δ%BMI (exposure variables).

RESULTS

ST increased and LPA decreased significantly for whole sample (both Ps < .05). No statistically significant difference was found for MVPA over time. There were no differences for ΔST, ΔLPA, ΔMVPA, and ΔBMI between boys and girls. The Δ%LPA and Δ%MVPA were negatively associated with Δ%ST, whereas Δ%BMI was positively associated. Tracking coefficients varied from moderate to strong.

CONCLUSIONS

Time spent in ST increases due to displacement of time in LPA. This reinforces public health measures and suggests the need for interventions focusing on offsetting the decline ST and increasing MVPA during childhood.

Associations Between Parenting Factors, Motivation, and Physical Activity in Overweight African American Adolescents

Background

Positive parenting practices and environmental supports have been linked to physical activity (PA) levels in youth, yet factors associated with positive parenting styles have been understudied in African American adolescents.

Purpose

This study expands on previous literature by examining associations between motivation, parenting factors associated with Self-Determination Theory's psychological needs (competence, autonomy, and relatedness) including authoritative parenting, autonomy support and emotional and tangible support, and adolescent moderate-to-vigorous PA (MVPA) and light PA (LPA).

Methods

Participants were African American adolescents (N = 148; Mage = 13.6 years; MBMI% = 96.6) and their care-givers (Mage = 43.4 years; MBMI = 37.4) enrolled in the Families Improving Together for Weight Loss trial. Parenting factors were measured using self-report surveys, and PA minutes were measured using 7-day accelerometry estimates.

Results

Regression analyses indicated that overall models for MVPA (F(11,134) = 4.35; R2 = 0.26) and LPA (F(11,134) = 5.84, R2 = 0.32) were significant. Adolescent motivation for PA (B = 0.58, SE = 0.16) was positively associated with MVPA minutes. Authoritative parenting (B = 15.71, SE = 4.38) and tangible support (B = 8.53, SE = 4.02) were positively associated with adolescent LPA minutes. Unexpectedly, emotional support was negatively associated with both MVPA (B = -0.47, SE = 0.17) and LPA (B = -11.22, SE = 4.79), with follow-up analyses showing this relationship stronger in males.

Conclusion

Findings highlight the importance of adolescent motivation for PA onMVPA and positive parenting styles and tangible supports on adolescent LPA in overweight African American youth. Recommendations for integrating these factors within the context of intervention studies are discussed.

Physical and Social Contexts of Physical Activity Behaviors of Fifth and Seventh Grade Youth

BACKGROUND

The purpose of this study was to characterize the temporal, social, and physical contexts for physical activities commonly reported in a diverse cohort of 753 boys and girls from fifth to seventh grade.

METHODS

Data were obtained from a multilevel longitudinal study, the Transitions and Activity Changes in Kids. The Physical Activity Choices instrument assessed previous 5-day participation in specific physical activities and their temporal, social, and physical contexts. Mixed model repeated measure analyses of variance and multinomial analyses examined sex differences and change over time.

RESULTS

Fifth grade boys and girls reported participation in similar activities at similar frequencies, which declined significantly by seventh grade. One temporal pattern, playing with younger children, changed over time from "both inside/outside" to "outside" school. Boys and females reported more activities performed in class/team groups over time. Most activities took place primarily at home for all participants in both grades.

CONCLUSIONS

Boys and girls reported declines in the variety and frequency of activities from fifth to seventh grade. There were sex-specific patterns in physical activities and groups; however, all participants reported home as the primary location and a shift to class/team groups over time. Schools are well-positioned to provide additional physical activity opportunities.

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

OBJECTIVES

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

DESIGN

Nationally representative longitudinal cohort study.

SETTING

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

PARTICIPANTS

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

PRIMARY AND SECONDARY OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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