Physical activity guidelines for children and adolescents: a critical review

Six months of different exercise type in sedentary primary schoolchildren: impact on physical fitness and saliva microbiota composition

Introduction

Lifestyle influences microbiota composition. We previously reported a healthier microbiota composition in saliva from active schoolchildren compared to sedentary. In the present study, we evaluated the effects of 6 months of different exercise types on physical fitness and saliva microbiota composition in 8-11-years-old sedentary schoolchildren.

Methods

Sixty-four sedentary children from five primary schools in Turin, Italy, were divided into three groups: one continued normal curricular activity while two underwent different exercise protocols for 6 months. The Structured Exercise (Sa) group did 2 h per week of muscle activation, strength and coordination exercises supervised by a kinesiologist. The Daily Mile (Dm) group did 1 h per week of Sa plus 15 min of walking/running outdoors four times a week, supervised by a class teacher; control group (Ct) did 2 h a week of curricular exercise supervised by a class teacher. Physical fitness was evaluated before and after the intervention. Saliva samples were collected post-intervention in all participants and analyzed using PCR amplification of 16S rRNA bacterial genes. The Amplicon Sequence Variants were filtered, decontaminated, and phylogenetically classified using DADA2 software. Differential abundance analysis of microbiome taxa and pathway data was conducted using the LEfSe algorithm and PICRUSt.

Results

The Sa group showed better performances in lower limb power and sprint performance while both the Sa and Dm groups improved in endurance and balance at the end of the intervention; only balance resulted slightly improved in the Ct group. Among the genera differently enriched in saliva after the training intervention, we found that the Prevotella, the Dubosiella and the Family XIII AD3011 group were the most abundant in the Sa group; differently, the Neisseria and the Abiotrophia in Ct group. Four species showed significant the Prevotella melaninogenica and the Prevotella nanceiensis were more abundant in the Sa, conversely, Gemella sanguinis was enriched in Dm and Abiotrophia defectiva in Ct saliva group.

Conclusion

We demonstrated that Sa and Dm, not curricular exercise, improve the physical fitness components in sedentary schoolchildren correlated to health and promote an enrichment in saliva microbiota species associated to a healthier profile.

Associations between Health Behaviors, Health Self-Efficacy, and Long-Term Outcomes in Survivors of Childhood Cancer: A Cross-Sectional Study

OBJECTIVES

Many survivors of childhood cancer experience multiple long-term chronic health conditions. Health behaviors are important because they contribute to chronic disease yet are highly modifiable. With growing pressure on cancer services, alternative models of care are required to address survivorship care needs. The authors sought to inform the development of a community-based model of cancer survivorship care for young people. This exploratory cross-sectional study aimed to assess the feasibility of study measures and processes, as well as investigate associations between various modifiable health behaviors, health self-efficacy, quality of life, and persistent symptoms.

DATA SOURCES

Participants were recruited from a long-term follow-up clinic for childhood cancer survivors. A self-report survey was completed, and participants received an activity tracker. Bivariate regression analyses were used to explore the relationship between variables.

CONCLUSIONS

The study measures and processes were deemed feasible with >70% of eligible survivors enrolling in the study and completing >70% of study measures. Thirty participants (mean age 22 ± 4.4 years) were enrolled; 83.3% finished treatment ≥5 years previously and 36.7% were overweight or obese. Bivariate regression identified those with higher scores of health self-efficacy were more likely to meet physical activity guidelines, as were those who achieved more sleep and consumed greater servings of vegetables. Meeting the physical activity guidelines, was significantly positively associated with higher quality of life and self-efficacy.

IMPLICATIONS FOR NURSING PRACTICE

Interventions that target health self-efficacy have the potential to improve a range of health behaviors and long-term outcomes for survivors of childhood cancer. Nurses are ideally placed to use this knowledge to support patients with recommendations to optimise their recovery and rehabilitation.

The short and long-term effects of a lifestyle intervention in children with mental illnesses: a randomized controlled trial (Movementss study)

BACKGROUND

A lifestyle including poor diet, physical inactivity, excessive gaming and inadequate sleep hygiene is frequently seen among Dutch children. These lifestyle behaviors can cause long-term health problems later in life. Unhealthy lifestyle and poor physical health are even more prevalent among children with mental illness (MI) such as autism, attention-deficit/hyperactivity disorder, depression, and anxiety. However, research on lifestyle interventions among children with MI is lacking. As a result, there are currently no guidelines, or treatment programs where children with MI and poor lifestyle can receive effective support. To address these issues and to provide insight into the effectiveness of lifestyle interventions in children with MI and their families, the Movementss study was designed. This paper describes the rationale, study design, and methods of an ongoing randomized controlled trial (RCT) comparing the short-term (12 weeks) and long-term (1 year) effects of a lifestyle intervention with care as usual (CAU) in children with MI and an unhealthy lifestyle.

METHODS

A total of 80 children (6-12 years) with MI according to DSM-V and an unhealthy lifestyle are randomized to the lifestyle intervention group or CAU at a specialized child and adolescent mental hospital. The primary outcome measure is quality of life measured with the KIDSCREEN. Secondary outcomes include emotional and behavior symptoms, lifestyle parameters regarding diet, physical activity, sleep, and screen time, cognitive assessment (intelligence and executive functions), physical measurements (e.g., BMI), parenting styles, and family functioning, prior beliefs, adherence, satisfaction, and cost-effectiveness. Assessments will take place at the start of the study (T0), after 12 weeks (T1), six months (T2), and 12 months of baseline (T3) to measure long-term effects.

DISCUSSION

This RCT will likely contribute to the currently lacking knowledge on lifestyle interventions in children with MI.

TRIAL REGISTRATION

trialsearch.who.int/ NL9822. Registered at November 2nd, 2021.

Exploratory examination of the association between physical-mental multimorbidity and physical activity in children

Children with physical illnesses often experience co-occurring mental illness (known as multimorbidity; MM) and it is currently unknown if MM is associated with physical activity (PA) and if the association differs between internalizing and externalizing disorders. Therefore, the aim of this study was to examine the association between MM and PA. Baseline data from the Multimorbidity in Children and Youth Across the Life Course (MY LIFE) cohort was used. MY LIFE is an ongoing prospective study that follows children ages 2 to 16 years with a chronic physical illness and measures PA using accelerometry and mental illness using the Mini International Neuropsychiatric Interview for Children and Adolescents. 140 children (53.2%) provided valid accelerometer data. Children with internalizing disorders recorded less light (B = -5.87), moderate (B = -1.82), and vigorous PA (B = -1.93) and fewer days meeting PA guidelines [Exp(B) = 0.73] and those with externalizing disorders recorded more light (B = 4.85), moderate (B = 1.78), and vigorous PA (B = 2.41) and more days meeting PA guidelines [Exp(B) = 1.06]. However, only the association between internalizing disorder and days meeting PA guidelines was statistically significant. This study provides preliminary evidence that children with MM may accumulate less PA depending on the type of mental illness they experience.

Physical activity and the 'pediatric inactivity triad' in children living with chronic kidney disease: a narrative review

The ‘paediatric inactivity triad’ (PIT) framework consists of three complex inter-related conditions that influence physical inactivity and related health risks. In those living with chronic kidney disease (CKD), a multi-factorial milieu of components likely confound the PIT elements, resulting in a cycle of decreased physical functioning and reduced physical activity. In this review, we explore and summarize previous research on each of the three principal PIT components (exercise deficit disorder, dynapenia, and physical illiteracy) in the pediatric CKD population. We found those living with CKD are significantly physically inactive compared to their peers. Physical inactivity occurs early in the disease process and progressively gets worse as disease burden increases. Although physical activity appears to increase post-transplantation, it remains lower compared to healthy controls. There is limited evidence on interventions to increase physical activity behaviour in this population, and those that have attempted have had negligible effects. Studies reported profound reductions in muscle strength, physical performance, and cardiorespiratory fitness. A small number of exercise-based interventions have shown favourable improvements in physical function and cardiorespiratory fitness, although small sample sizes and methodological issues preclude the generalization of findings. Physical activity must be adapted and individualized to the needs and goals of the children, particularly those with acute and chronic medical needs as is the case in CKD, and further work is needed to define optimal interventions across the life course in this population if we aim to prevent physical activity declining further.

Transfer Learning Improves Accelerometer-Based Child Activity Recognition via Subject-Independent Adult-Domain Adaption

Wearable activity recognition can collate the type, intensity, and duration of each childs physical activity profile, which is important for exploring underlying adolescent health mechanisms. Traditional machine-learning-based approaches require large labeled data sets; however, child activity data sets are typically small and insufficient. Thus, we proposed a transfer learning approach that adapts adult-domain data to train a high-fidelity, subject-independent model for child activity recognition. Twenty children and twenty adults wore an accelerometer wristband while performing walking, running, sitting, and rope skipping activities. Activity classification accuracy was determined via the traditional machine learning approach without transfer learning and with the proposed subject-independent transfer learning approach. Results showed that transfer learning increased classification accuracy to 91.4% as compared to 80.6% without transfer learning. These results suggest that subject-independent transfer learning can improve accuracy and potentially reduce the size of the required child data sets to enable physical activity monitoring systems to be adopted more widely, quickly, and economically for children and provide deeper insights into injury prevention and health promotion strategies.

Design and psychometrics evaluation of Adolescent Physical Literacy Questionnaire (APLQ)

Purpose

Despite the global introduction of physical literacy in recent years, a lack of a comprehensive physical literacy tool is still evident in adolescents. This study was conducted to design and perform psychometric evaluation of self-assessment adolescent physical literacy questionnaire in the Iranian sample.

Methods

A mixed research method, including 3 phases, was used on 836 adolescents in the age range of 12-18 years old. A questionnaire with 59 items was designed based on the qualitative stage, refined during the validity and reliability stages, and finally, formed a questionnaire with 25 items.

Results

The exploratory factor analysis showed 3 factors with an explanation of 59.5% of the total variance, and the results of confirmatory factor analysis confirmed the 3-factor model. Results also showed good internal consistency (α = 0.951), retest reliability (0.981-0.837), and concurrent validity of the questionnaire with the PPLI instrument (0.680-0.790).

Conclusion

The results showed good validity and reliability of the Adolescent Physical Literacy Questionnaire (APLQ) with 3 dimensions. Therefore, it can be a suitable tool to assess adolescent physical literacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11332-021-00818-8.

Effects of a Physical Education Program on Physical Activity and Emotional Well-Being among Primary School Children

(1) Background: It has been identified that schools that adopt at least two hours a week of physical education and plan specific contents and activities can achieve development goals related to physical level, such as promoting health, well-being, and healthy lifestyles, on a personal level, including bodily awareness and confidence in physical skills, as well as a general sense of well-being, greater security and self-esteem, sense of responsibility, patience, courage, and mental balance. The purpose of this study was to establish the effect of physical education programs on the physical activity and emotional well-being of primary school children. (2) Methods: The experimental group comprised 45 girls and 44 boys aged 6-7 years (First Grade) and 48 girls and 46 boys aged 8-9 years (Second Grade), while the control group comprised 43 girls and 46 boys aged 6-7 years (First Grade) and 47 girls and 45 boys aged 8-9 years (Second Grade). All children attended the same school. The Children's Physical Activity Questionnaire was used, which is based on the Children's Leisure Activities Study Survey questionnaire, which includes activities specific to young children (e.g., "playing in a playhouse"). Emotional well-being status was explored by estimating three main dimensions: somatic anxiety, personality anxiety, and social anxiety. The Revised Children's Manifest Anxiety Scale (RCMAS) was used. (3) Results: When analysing the pre-test results of physical activity of the 6-7- and 8-9-year-old children, it turned out that both the First Grade (92.15 MET, min/week) and Second Grade (97.50 MET, min/week) participants in the experimental group were physically active during physical education lessons. When exploring the results of somatic anxiety in EG (4.95 ± 1.10 points), both before and after the experiment, we established that somatic anxiety in EG was 4.55 ± 1.00 points after the intervention program, demonstrating lower levels of depression, seclusion, somatic complaints, aggression, and delinquent behaviours (F = 4.785, p < 0.05, P = 0.540). (4) Conclusions: We established that the properly constructed and purposefully applied eight-month physical education program had positive effects on the physical activity and emotional well-being of primary school children (6-7 and 8-9 years) in three main dimensions: somatic anxiety, personality anxiety, and social anxiety. Our findings suggest that the eight-month physical education program intervention was effective at increasing levels of physical activity. Changes in these activities may require more intensive behavioural interventions with children or upstream interventions at the family and societal levels, as well as at the school environment level. These findings have relevance for researchers, policy makers, public health practitioners, and doctors who are involved in health promotion, policy making, and commissioning services.

Built-environment attributes associated with refugee children's physical activity: a narrative review and research agenda

Research has identified built environmental attributes associated with children’s physical activity (PA); however, less is known for environmental correlates of refugee children’s PA. This narrative review summarised the current evidence of associations between built environment attributes and refugee children’s PA. Six databases were searched with three sets of terms related to exposure (built environment); outcome (PA); and target population (refugee children aged 6–12 years). Eight studies (one quantitative; seven qualitative) met the inclusion criteria. Key PA barriers were limited play space and lack of neighbourhood safety. Design of refugee facilities and surrounding environments should provide better access to formal, informal and safe spaces for children’s play.

The impact of COVID-19 on Physical Activity of Czech children

INTRODUCTION

The pandemic of coronavirus disease (COVID-19) and related restrictions (closed schools and sports centers, social isolation, masks) may have a negative impact on children's health. The purpose of this study was to evaluate the level of physical activity (PA) of Czech children during COVID-19 in autumn 2020.

METHODS

Ninety-eight Czech children (mean age = 10.1 ± 1.47 years) completed the standardized Physical Activity Questionnaire for Older Czech Children (PAQ-C/cz) during COVID lockdown. Data were compared with previously published norms. Thirty-five children also reported daily number of steps measured by accelerometers.

RESULTS

Total PAQ-C score was 0.38 lower during COVID compared to Pre-COVID [t(302) = 5.118., p < .001]. The male PAQ-C total score was 0.37 lower [t(146) = 3.21., p = .002)] and the female total score was 0.39 lower [t(154) = 3.97., p < .001] during COVID compared to Pre-COVID. Specifically, responses of PA during spare time, before-school, physical education (PE), and recess were significantly lower during COVID. The average number of steps was 7.767 steps/day (boys = 9.255; girls = 6.982).

CONCLUSION

COVID lockdown resulted in significant reduction of PA in Czech children. Strategies to promote adequate PA of children during the pandemic need to be determined.

Impact of a behaviourally focused nutrition education intervention on attitudes and practices related to eating habits and activity levels in Indian adolescents

OBJECTIVE

To evaluate the effectiveness of a behaviourally focused nutrition education (NE) intervention based on the Health Belief Model (HBM) to improve knowledge, attitudes and practices (KAP) related to eating habits and activity levels in 10–12-year-old adolescents in Mumbai, India.

DESIGN

School-based cluster randomised controlled trial. The experimental group (EG) received weekly NE and three parent sessions over 12 weeks; no sessions were conducted for the control group (CG). The theoretical framework of HBM and focus group discussion results guided the development of behaviour change communication strategies and NE aids. KAP were measured using a validated survey instrument, administered at baseline and endline in EG and CG. Paired and independent t tests determined within-group and between-group changes in pre–post scores.

SETTING

Two aided and two private schools that were randomly allocated to either an EG or CG.

PARTICIPANTS

Adolescent boys and girls (n 498; EG n 292 and CG n 206).

RESULTS

EG reported improvements in mean knowledge (39·3%), attitude (7·3 %), diet (9·6 %) and activity practice (9·4%) scores from pre to post intervention. No significant changes were observed in CG. Significant improvements in scores associated with perceived benefits, barriers and self-efficacy, breakfast and vegetable consumption, and moderate-to-vigorous activities were observed in EG.

CONCLUSIONS

Integrating NE into the academic curriculum and adopting evidence-based lessons that entail targeted information delivery and participatory activities can improve knowledge, foster right attitudes and facilitate better eating and activity-related practices in Indian adolescents.

Effects of early-life exposure to Western diet and voluntary exercise on adult activity levels, exercise physiology, and associated traits in selectively bred High Runner mice

Exercise behavior is under partial genetic control, but it is also affected by numerous environmental factors, potentially including early-life experiences whose effects persist into adulthood. We studied genetic and early-life environmental effects on wheel-running behavior in a mouse model that includes four replicate high runner (HR) lines selectively bred for increased voluntary wheel running as young adults and four non-selected control (C) lines. In a full factorial design, mice from each line were granted wheel access or not and administered either standard or Western diet (WD) from weaning (3 weeks old) to 6 weeks of age (sexual maturity). In addition to acute effects, after a washout period of 8 weeks (∼6 human years) in which all mice had standard diet and no wheel access, we found both beneficial and detrimental effects of these early-life exposures. During the first week of treatments, WD increased distance run by 29% in C mice and 48% in HR mice (significant Diet × Linetype interaction), but diet effects disappeared by the third week. Across the three weeks of juvenile treatment, WD significantly increased fat mass (with lean mass as a covariate). Tested as adults, early-life exercise increased wheel running of C mice but not HR mice in the first week. Early-life exercise also reduced adult anxiety-like behavior and increased adult fasted blood glucose levels, triceps surae mass, subdermal fat pad mass, and brain mass, but decreased heart ventricle mass. Using fat mass as a covariate, early-life exercise treatment increased adult leptin concentration. In contrast, early-life WD increased adult wheel running of HR mice but not C mice. Early-life WD also increased adult lean mass and adult preference for Western diet in all groups. Surprisingly, early-life treatment had no significant effect on adult body fat or maximal aerobic capacity (VO2max). No previous study has tested for combined or interactive effects of early-life WD and exercise. Our results demonstrate that both factors can have long-lasting effects on adult voluntary exercise and related phenotypes, and that these effects are modulated by genetic background. Overall, the long-lasting effects of early-life exercise were more pervasive than those of WD, suggesting critical opportunities for health intervention in childhood habits, as well as possible threats from modern challenges. These results may be relevant for understanding potential effects of activity reductions and dietary changes associated with the obesity epidemic and COVID-19 pandemic.

The Association between Vigorous Physical Activity and Stress in Adolescents with Asthma

Asthma is a very common condition that affects 5-10% of the global population, and its prevalence is increasing. Vigorous physical activity (PA) is effective in improving cardiorespiratory fitness and managing stress. This study aimed to investigate the association between vigorous PA and stress among Korean adolescents with asthma using large-scale survey data. The questionnaire data of 57,303 adolescents were analyzed using raw data from the 2019 Korea Youth Risk Behavior Web-Based Survey. We performed logistic regression analysis to calculate the stress odds ratios (ORs) and 95% confidence intervals (CIs) for asthma and non-asthma groups using models 1 and 2. We also performed logistic regression analysis to calculate the stress OR for the asthma group with vigorous PA and non-vigorous PA using models 1, 2, and 3. Model 1 was adjusted for age, sex, obesity, smoking, and alcohol status; model 2 was further adjusted for household income, academic achievement, and comorbidities. Model 3 was further adjusted for moderate activity and resistance exercise. The OR of stress was 20% higher in the asthma group than in the non-asthma group (p < 0.05). In the fully adjusted models, the OR for the non-asthma group with vigorous PA versus non-vigorous PA was 0.89 (95% CI: 0.84-0.94). However, the OR for the asthma group with vigorous PA versus non-vigorous PA was 0.70 (95% CI: 0.57-0.86), indicating that adolescents who engage in vigorous PA had lower stress in the asthma group (p < 0.05). This study demonstrated that adolescents with asthma had higher stress levels than those without asthma; however, vigorous PA was associated with lower stress. These effects were more pronounced in adolescents with asthma.

Associations between Stress and Physical Activity in Korean Adolescents with Atopic Dermatitis Based on the 2018-2019 Korea Youth Risk Behavior Web-Based Survey

This study aimed to confirm the associations between stress and physical activity (PA) in Korean adolescents with atopic dermatitis (AD) based on data from the 2018-2019 Korea Youth Risk Behavior Web-Based Survey. The AD groups were divided into adolescents who were not diagnosed with AD, adolescents who were diagnosed with AD more than one year ago, and adolescents who were diagnosed with AD within one year. We defined the regular PA group and the non-PA group using the American College of Sports Medicine guidelines for children and adolescents: moderate to vigorous PA ≥5 times per week, including vigorous PA ≥3 days per week and muscle strengthening exercises ≥3 times per week. We performed logistic regression analysis to calculate the stress odds ratio (OR) and 95% confidence interval (CI) by group using model 1, adjusted for age, sex, and body mass index, and model 2, additionally adjusted for drinking, smoking, economic statuses, academic achievement, asthma, and rhinitis. In the group diagnosed with AD within one year, stress was 41% and 32% higher according to models 1 (1.41 (1.31-1.52)) and 2 (1.34 (1.20-1.50)), respectively. However, the stress OR was 30% lower in adolescents who completed regular PA than in the non-PA group (model 1: 0.71 (0.58-0.87); model 2: 0.68 (0.57-0.84)), even if diagnosed with AD within one year. In conclusion, the stress of adolescents with AD was significantly higher than that of adolescents without AD. The stress was significantly lower in the group with regular PA, and it was more robust in adolescents diagnosed with AD within one year.

Accelerometer-measured Physical Activity, Reproductive Hormones, and DNA Methylation

INTRODUCTION/PURPOSE

Limited studies have examined the association of physical activity with reproductive hormones, DNA methylation, and pubertal status among adolescents.

METHODS

Among 248 boys and 271 girls, we estimated daily physical activity levels based on 7 d of wrist-worn accelerometer data. We used an isotemporal substitution paradigm and sex-stratified regression models to examine the association of physical activity levels with 1) testosterone, cortisol, progesterone, and androstenedione concentrations; 2) DNA methylation of long interspersed nucleotide (LINE-1) repeats and the genes H19, hydroxysteroid (11-Beta) dehydrogenase 2 (HSD11B2), and peroxisome proliferator-activated receptor alpha (PPARA) from blood leukocytes; and 3) Tanner stages, adjusted for age, BMI, and socioeconomic status.

RESULTS

In boys, substituting 30 min of moderate physical activity for 30 min of sedentary behavior per day was associated with 29% (-49%, 0%) of lower testosterone and 29% (4%, 61%) of higher progesterone. Substituting 30 min of light physical activity for sedentary behavior was associated with 13% (-22%, -2%) of lower progesterone. Among girls, 30 min of additional sedentary behavior was associated with 8% (-15%, 0%) of lower testosterone and 24% (8%, 42%) of higher progesterone concentrations. Substituting 30 min of moderate physical activity for sedentary behavior was associated with 15% (0%, 31%) of higher cortisol, whereas substituting the same amount of light physical activity for sedentary behavior was associated with 22% (-39%, 0%) of lower progesterone. Substituting 30 min of vigorous physical activity for sedentary behavior per day was associated with almost six times higher levels (5.83, 95% confidence interval = 1.79-9.86) of HSD11B2 methylation in boys.

CONCLUSIONS

Accelerometer-measured daily physical activity was associated with reproductive hormones and HSD11B2 DNA methylation, differed by sex and activity intensity levels.

Association of the built environment with physical activity in children and adolescents in Africa: a systematic review protocol

OBJECTIVE

The objective of this systematic review is to summarize the association between the built environment and physical activity in children and adolescents in Africa.

INTRODUCTION

Physical activity offers immense benefits to children and adolescents. Some built environment constructs, such as street connectivity and the availability of parks, have been identified to facilitate physical activity in children and adolescents; however, this evidence has come from developed countries. This review will present evidence from Africa on the built environment constructs that facilitate physical activity in children and adolescents.

INCLUSION CRITERIA

This review will consider quantitative studies that have built environment constructs as one of their exposure variables and physical activity as one of their outcomes and were conducted in children and adolescents aged five to 19 years residing in Africa.

METHODS

A systematic search of MEDLINE, Embase, Web of Science and other sources will be conducted to locate both published and unpublished studies. There will be no date or language restrictions. Titles, abstracts, and full text of articles retrieved from the search will be screened and read by two reviewers independently for eligibility. Included articles will be critically appraised independently by two reviewers. Data extraction will be performed in two phases, first for information regarding the study characteristics and then to extract specific study findings. Meta-analysis will be used to synthesize the findings from the studies; however, where this is not possible, a narrative synthesis will be performed.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019133324.

Decline of physical activity in early adolescence: A 3-year cohort study

This study analyses the changes of moderate-to-vigorous physical activity (MVPA) in a cohort of boys and girls aged 11 (n = 50) and 14 (n = 50). Physical activity was assessed with Bodymedia SenseWear Pro Armband monitor for 6 days in October 2013 and October 2016, considering 90% of daily wear time (21h and 40min). The initial sample (n = 160) included the children who wore the monitors at age 11 but the final analyzed sample included only those children from the initial sample (n = 50), whose data fulfilled the inclusion criteria at age 11 and 14. Physical fitness and somatic characteristics of the final sample (n = 50) were compared to a representative sample of Slovenian schoolchildren at ages 11 (n = 385) and 14 (n = 236) to detect possible bias. Changes in MVPA were controlled for maturity using the timing of adolescent growth spurt as its indicator. The average MVPA decreased more than one quarter (34.96 min) from age 11 to age 14. Children were significantly more active at age 11 than at age 14 (p < 0.01, d = 0.39). The timing of puberty onset in girls was significantly earlier (12.01 ± 1.0 years) (p < 0.01) than in boys (13.2 ± 0.75 years) (p < 0.01, d = 1.35). There was a significant gender difference in moderate-to vigorous physical activity at age 14 (p < 0.05, η2 = 0.12) and between moderate-to vigorous physical activity at age 11 and 14 (η2 = 0.11). After controlling for the timing of adolescent growth spurt the girls at age 11 showed significantly higher level of physical activity than at age 14 (p < 0.01, η2 = 0.17). Early adolescence is crucial for the development of physical activity behaviours, which is especially pronounced in girls. The significant decline of MVPA between ages 11 and 14 in Slovenia are likely influenced by environmental changes since the timing of adolescent growth spurt did not prove as a factor underlying the decline of MVPA.

Effects of physical activity on children's growth

OBJECTIVE

To describe the current scientific knowledge on the effects of physical exercise on the growth of children and adolescents since intrauterine life.

SOURCE OF DATA

A search was carried out in the Medline, Embase, Scielo, and Cochrane databases of studies published from 1990 to 2018. The authors included studies with different designs: clinical trials, cohort, cross-sectional and review studies.

SYNTHESIS OF DATA

Studies that addressed the subject of physical exercise or physical activity, and weight-height growth or bone or muscle tissue growth were identified. These studies were analyzed, classified, and presented by age group: fetuses, preterm newborns, preschoolers, schoolchildren, and adolescents. It was observed that almost all studies indicated the safety of physical exercises, of mild to moderate intensity, for pregnant women, as well as children and adolescents, including both aerobic and anaerobic exercises. The retrieve studies did not demonstrate that the practice of physical exercises or certain sports, especially basketball and floor gymnastics, influenced the linear growth of children or adolescents. Some studies showed an increase in bone and muscle tissue growth in child and adolescent athletes.

CONCLUSIONS

Despite the small number of studies with adequate methodology, especially randomized clinical trials, evidence appears to indicate that physical exercise is safe for both the pregnant woman and the child, from fetal life to adolescence. Physical exercise does not appear to impair the child's linear growth and contributes to the ideal shaping of bone and muscle tissues, ensuring possible beneficial effects throughout life.

Active and Healthy Lifestyle - Nationwide Programs in Israeli Schools

The World Health Organization (WHO) announced the 'Global School Health Initiative' in 1995 following recommendations formulated in the Ottawa Charter for Health Promotion. Hence, the aims of the present study were to describe the various programs for nurturing an active and healthy lifestyle implemented during 2011-12 in schools in Israel, and to identify variables that may explain the success versus lack of success in implementing these programs. Participants were a nationwide representative sample of 126 school principals from six supervisory districts of the Ministry of Education, including six sectors, from the elementary, junior-high and senior-high school levels. Semi-structured telephone interviews were recorded and processed using the ATLAS.ti software for qualitative analysis. Physical education teachers, sciences teachers and social coordinators led the programs' implementation. The programs included four main activities domains: health, physical education, nutrition and sustainability. Three types of program implementation were observed: leading principles, teaching methods, and external programs. Parents were involved mostly in elementary schools. Evidence of program integration into school life was presented by changes in children's behaviors, whereas difficulties stemmed from lack of budget and teaching hours. Science and physical education lessons constituted the anchor for the programs. The schools needed a committed leader to help conduct and maintain the program. Thus, the role of the school principal was to initiate the idea of developing a program, encourage its implementation, select a leader for the program, and then, most importantly, to reinforce the teachers' enthusiasm.

Summer Healthy-Lifestyle Intervention Program for Young Children Who Are Overweight: Results from a Nonrandomized Pilot Trial

OBJECTIVE

To examine initial outcomes of an 8-week Healthy-Lifestyle Intervention Program (HIP) which included children's participation in a daily summer camp along with parents' participation in a parenting program focused on overweight/obesity.

METHODS

Using a nonrandomized pilot trial design, 16 children (M child age = 6.42 yr; 81% male; 100% Latino) classified as overweight/obese and their mothers completed 3 assessments (baseline, posttreatment, and 6-8 mo follow-up).

RESULTS

Children who completed HIP experienced significant decreases in their body mass index z-scores (primary outcome) from baseline to posttreatment (d = -1.11) with such decreases being moderately maintained at follow-up (d = -0.64). In terms of secondary outcomes, HIP was effective in improving and maintaining healthy habits in both children and mothers and children's nutritional knowledge and fitness. Objective food data showed that children's dietary intake during HIP improved. High attendance and satisfaction were reported for families who completed HIP.

CONCLUSION

This pilot treatment development study shows that a family lifestyle intervention conducted in a summer camp setting that targets both children and parents is a promising option for addressing pediatric obesity in young children.

Improving Physical Fitness and Cognitive Functions in Middle School Students: Study Protocol for the Chinese Childhood Health, Activity and Motor Performance Study (Chinese CHAMPS)

Background: Sedentary lifestyles and their associated harmful consequences are public health concerns that impact more than half of the world’s youth population in both developed and developing countries. Methods: The Chinese Childhood Health; Activity and Motor Performance Study (Chinese CHAMPS) was a cluster randomized controlled trial to modify school physical activity policies and the physical education (PE) curriculum; using teacher training and parent engagement to increase opportunities and support students’ physical activity and healthy eating. Using a 2 × 2 factorial design, the study tested the incremental effects of increasing the amount and intensity of physical activity, alongside adding support for healthy eating, on health-related and cognitive function outcomes in Chinese middle school students. Results: The intervention was implemented by PE teachers in 12 middle schools in three Chinese cities, with a targeted enrollment of 650 students from August 2015–June 2016. The assessment of the outcomes involved a test battery of physical fitness and cognitive functioning at both baseline and at the end of the intervention. Process information on implementation was also collected. Discussion: The Chinese CHAMPS is a multi-level intervention that is designed to test the influences of policy and environmental modifications on the physical activity and eating behaviors of middle school students. It also addresses some key weaknesses in school-based physical activity interventions.

Comparison of accelerometer measured levels of physical activity and sedentary time between obese and non-obese children and adolescents: a systematic review

Background

Obesity has been hypothesized to be associated with reduced moderate-to-vigorous physical activity (MVPA) and increased sedentary time (ST). It is important to assess whether, and the extent to which, levels of MVPA and ST are suboptimal among children and adolescents with obesity. The primary objective of this study was to examine accelerometer-measured time spent in MVPA and ST of children and adolescents with obesity, compared with MVPA recommendations, and with non-obese peers.

Methods

An extensive search was carried out in Medline, Cochrane library, EMBASE, SPORTDiscus, and CINAHL, from 2000 to 2015. Study selection and appraisal: studies with accelerometer-measured MVPA and/or ST (at least 3 days and 6 h/day) in free-living obese children and adolescents (0 to 19 years) were included. Study quality was assessed formally. Meta-analyses were planned for all outcomes but were precluded due to the high levels of heterogeneity across studies. Therefore, narrative syntheses were employed for all the outcomes.

Results

Out of 1503 records, 26 studies were eligible (n = 14,739 participants; n = 3523 with obesity); 6/26 studies involved children aged 0 to 9 years and 18/26 involved adolescents aged 10.1 to19 years. In the participants with obesity, the time spent in MVPA was consistently below the recommended 60 min/day and ST was generally high regardless of the participant’s age and gender. Comparison with controls suggested that the time spent in MVPA was significantly lower in children and adolescents with obesity, though differences were relatively small. Levels of MVPA in the obese and non-obese were consistently below recommendations. There were no marked differences in ST between obese and non-obese peers.

Conclusions

MVPA in children and adolescents with obesity tends to be well below international recommendations. Substantial effort is likely to be required to achieve the recommended levels of MVPA among obese individuals in obesity treatment interventions.

This systematic review has been registered on PROSPERO (International Database of Prospective Register Systematic Reviews; registration number CRD42015026882).

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1031-0) contains supplementary material, which is available to authorized users.

Structural differences in the lower extremities in children aged 7-9 years, caused by playing football: A cross-sectional study

BACKGROUND

Physical activity during childhood can be beneficial in the long term. However, this practice can influence the child's physiological development. The aim of this study was to determine whether the practice of soccer, in moderation, could be a risk factor for the inadequate development of the lower limb.

METHODS

The study group was composed of 115 children, of whom 59 (mean age 8.03±0.89years) practised soccer 3 times a week and had a positive Physical Activity Questionnaire for Adolescents (PAQ-A) score, while a further 56 (mean age 7.96±0.87years) did not perform any additional physical activity and had a negative PAQ-A score. A foot posture analysis, based on the foot posture index (FPI), the valgus index, the orientation of the subtalar joint (STJ) and the Q angle of the knee, was carried out.

RESULTS

For the group of soccer players, the following results were obtained: FPI 4.79±2.38 (R) and 3.95±2.31 (L); valgus index 13.56°±1.66° (R) and 13.42°±1.48° (L); STJ test 79% pronated; Q angle 13.13°±2.06° (R) and 13.18°±1.93° (L). For the non-players, the corresponding values were: FPI 3.62±2.82 (R) and 3.74±2.77 (L); valgus index 12.76°±1.71° (R) and 12.84°±1.72° (L); STJ test 50% pronated; Q angle 13.87°±3.01° (R) and 13.86°±2.94° (L).

CONCLUSION

There is a degree of difference between the two groups, but the values do not vary greatly from those considered normal for this age group. Any alterations in this respect can be assumed to be caused at older ages than those analysed.

Associations between parental support for physical activity and moderate-to-vigorous physical activity among Chinese school children: A cross-sectional study

PURPOSE

The objective of this study was to examine the associations between parental support for physical activity (PA) and levels of moderate-to-vigorous physical activity (MVPA) among Chinese school children.

METHODS

Study participants were 81,857 school-aged children (aged 9-17 years; mean age = 13 years; 49.0% boys) and their parents or guardians who took part in the 2016 Physical Activity and Fitness in China-The Youth Study project. The independent variables included various forms of parental support for PA ascertained through a survey completed by parents or guardians. The dependent variable was the children's average MVPA in minutes per day by self-report. Structure equation modeling was used to examine the associations between parental support for PA and children's MVPA minutes.

RESULTS

The overall mean for MVPA participation time for the child participants was 48.82 ± 28.71 min/day. Significant associations between various forms of parental support and MVPA among children were found. Parental encouragement, accompanying, financial support, involvement, and role modeling for PA were positively associated with a high level of student MVPA participation. Parental PA knowledge-sharing was not associated with MVPA. The patterns of the associations were similar across sex, residence locale (i.e., urban and rural), and school grades (primary, junior middle, and junior high schools).

CONCLUSION

Findings from this study suggest that, among Chinese school children, parental support for PA is important in promoting and facilitating children's participation in MVPA.

Accelerometer measured levels of moderate-to-vigorous intensity physical activity and sedentary time in children and adolescents with chronic disease: A systematic review and meta-analysis

Context

Moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) are important for child and adolescent health.

Objective

To examine habitual levels of accelerometer measured MVPA and ST in children and adolescents with chronic disease, and how these levels compare with healthy peers.

Methods

Data sources: An extensive search was carried out in Medline, Cochrane library, EMBASE, SPORTDiscus and CINAHL from 2000–2017.

Study selection: Studies with accelerometer-measured MVPA and/or ST (at least 3 days and 6 hours/day to provide estimates of habitual levels) in children 0–19 years of age with chronic diseases but without co-morbidities that would present major impediments to physical activity. In all cases patients were studied while well and clinically stable.

Results

Out of 1592 records, 25 studies were eligible, in four chronic disease categories: cardiovascular disease (7 studies), respiratory disease (7 studies), diabetes (8 studies), and malignancy (3 studies). Patient MVPA was generally below the recommended 60 min/day and ST generally high regardless of the disease condition. Comparison with healthy controls suggested no marked differences in MVPA between controls and patients with cardiovascular disease (1 study, n = 42) and type 1 diabetes (5 studies, n = 400; SMD -0.70, 95% CI -1.89 to 0.48, p = 0.25). In patients with respiratory disease, MVPA was lower in patients than controls (4 studies, n = 470; SMD -0.39, 95% CI -0.80, 0.02, p = 0.06). Meta-analysis indicated significantly lower MVPA in patients with malignancies than in the controls (2 studies, n = 90; SMD -2.2, 95% CI -4.08 to -0.26, p = 0.03). Time spent sedentary was significantly higher in patients in 4/10 studies compared with healthy control groups, significantly lower in 1 study, while 5 studies showed no significant group difference.

Conclusions

MVPA in children/adolescents with chronic disease appear to be well below guideline recommendations, although comparable with activity levels of their healthy peers except for children with malignancies. Tailored and disease appropriate intervention strategies may be needed to increase MVPA and reduce ST in children and adolescents with chronic disease.

Effects of a Curricular Physical Activity Intervention on Children's School Performance, Wellness, and Brain Development

BACKGROUND

Physical activity and structural differences in the hippocampus have been linked to educational outcome. We investigated whether a curriculum-based physical activity intervention correlates positively with children's academic achievement, psychological well-being, health-related quality of life (HRQoL), fitness, and structural development of the brain.

METHODS

The study had a quasi-experimental design and a control group. National test results were gathered from 545 students, 122 in the intervention school, and 423 in 3 control schools. HRQoL and socioemotional data were collected with child and proxy versions of KIDSCREEN and the Strength and Difficulties Questionnaire. Overall, 79 students in grades 5 and 6 were recruited for an in-depth study, consisting of a submaximal oxygen consumption test and magnetic resonance imaging of the brain. HRQoL and socioemotional data were collected from 349 students (65%), 182 (52%) in the intervention school, and 167 (48%) in one of the control schools.

RESULTS

Girls attending the intervention school were more likely to pass national tests in Swedish (odds ratio 5.7) and Mathematics (odds ratio 3.2). The fourth to sixth graders in the intervention school reported lower levels of conduct problems (p < .05), and the girls were also less likely to report hyperactivity (p < .05). Girls reported higher levels of emotional problems (p < .05) than boys. Boys in the intervention group had significantly higher levels of estimated maximal oxygen uptake (p < .05) than controls. No difference in hippocampal structure was seen.

CONCLUSIONS

Curriculum-based physical activity in school may improve the academic achievement and psychological health of children, particularly for girls.

Associação entre IMC e teste de coordenação corporal para crianças (KTK). Uma meta-análise

O Teste de Coordenação Corporal para Crianças (Körperkoordinationstest für Kinder, KTK) tem sido utilizado na avaliação da coordenação motora de crianças e adolescentes. O objetivo desta revisão sistemática com meta-análise foi analisar a relação entre o índice de massa corporal (IMC) e o desempenho motor no KTK em crianças e jovens escolares saudáveis. O estudo baseou-se em pesquisas indexadas nas bases eletrônicas PubMed e SciELO. Os descritores foram: "Körperkoordinationstest für Kinder" e "KTK". Foram considerados artigos em inglês e português publicados até Outubro de 2014. A qualidade dos estudos foi determinada pelas Escalas PEDro e STROBE. Foi realizada meta-análise utilizando o software Comprehensive Meta-Analysis V2. Foram incluídos 10 estudos. O resultado global com base no modelo de efeitos fixos mostrou que valores maiores de IMC estão diretamente associados ao baixo desempenho no KTK. Apesar da pequena diferença entre ambos, a magnitude do efeito da associação foi classificada como pequena, porém, significativa para o sexo masculino (r=0,29; IC95% 0,27 a 0,32; Z=22,47; p=0,000) e moderada para o sexo feminino (r=0,32; IC95% 0,30 a 0,34; Z=24,76; p=0,000). Os estudos apresentaram características amostrais bastante divergentes quanto ao tamanho da amostra e a faixa etária dos sujeitos, além de nenhum deles ter analisado o estado maturacional dos participantes. Conclui-se que há uma tendência de relação positiva entre valores elevados de IMC e o baixo desempenho no KTK. Para confirmação desta tendência, recomenda-se que os próximos trabalhos considerem o estado maturacional dos participantes, além de possibilitarem uma análise por sexo e idade.

Markers of adiposity among children and adolescents: implications of the isotemporal substitution paradigm with sedentary behavior and physical activity patterns

Background

The purpose of this study was to examine the association between daily movement patterns and dual energy X-ray absorptiometry-determined body fat percent (DXA-BF%) among children and adolescents while applying both traditional and novel analytical procedures.

Methods

Using data from the cross-sectional 2003–2006 National Health and Nutrition Examination Survey (n = 5607), physical activity was assessed via accelerometry, with the following movement patterns assessed: 1) meeting moderate-to-vigorous physical activity (MVPA) guidelines and engaging in more light-intensity physical activity (LIPA) than sedentary behavior (SB); 2) meeting MVPA guidelines, but engaging in less LIPA than SB; 3) not meeting MVPA guidelines, but engaging in more LIPA than SB; and 4) not meeting MVPA guidelines and engaging in less LIPA than SB. Various markers of adiposity (e.g., DXA-BF%) were assessed.

Results

Children in movement pattern 1 (52 %), compared to those in movement pattern 4, had significantly lower levels of BMI (∆ 2.2 kg/m²), waist circumference (∆ 6.5 cm), tricep skinfold (∆ 4.2 mm), subscapularis skinfold (∆ 2.6 mm), android BF% (∆ 7.6 %), gynoid BF% (∆ 5.1 %), and total BF% (∆ 5.2 %). Substituting 60 min/day of SB with MVPA resulted in a 4.6 % decreased estimate of total DXA-BF%. No findings were significant for adolescents.

Conclusions

The low proportion of children engaging in ≥ 60 min/day of MVPA and accumulating relatively more LIPA than SB had the lowest DXA-BF%.

Self-regulatory mode (locomotion and assessment), well-being (subjective and psychological), and exercise behavior (frequency and intensity) in relation to high school pupils' academic achievement

Background. Self-regulation is the procedure implemented by an individual striving to reach a goal and consists of two inter-related strategies: assessment and locomotion. Moreover, both subjective and psychological well-being along exercise behaviour might also play a role on adolescents academic achievement.

Method. Participants were 160 Swedish high school pupils (111 boys and 49 girls) with an age mean of 17.74 (sd = 1.29). We used the Regulatory Mode Questionnaire to measure self-regulation strategies (i.e., locomotion and assessment). Well-being was measured using Ryff’s Psychological Well-Being Scales short version, the Temporal Satisfaction with Life Scale, and the Positive Affect and Negative Affect Schedule. Exercise behaviour was self-reported using questions pertaining to frequency and intensity of exercise compliance. Academic achievement was operationalized through the pupils’ mean value of final grades in Swedish, Mathematics, English, and Physical Education. Both correlation and regressions analyses were conducted.

Results. Academic achievement was positively related to assessment, well-being, and frequent/intensive exercise behaviour. Assessment was, however, negatively related to well-being. Locomotion on the other hand was positively associated to well-being and also to exercise behaviour.

Conclusions. The results suggest a dual (in)direct model to increase pupils’ academic achievement and well-being—assessment being directly related to higher academic achievement, while locomotion is related to frequently exercising and well-being, which in turn, increase academic achievement.

Systematic review shows only few reliable studies of physical activity intervention in adolescents

Introduction. Several studies have pointed to the high prevalence of low levels of physical activity in adolescents, suggesting the need for more effective interventions for this group. The aim of this study was to present evidence of intervention programs for efficacy of physical activity for adolescents. Methods. Surveys in PubMed, SportDiscus, LiLacs, and SciELO databases were conducted using keywords to identify population, intervention, and outcome, as well as DeCS and MeSH terms in English, Portuguese, and Spanish, whenever appropriate. The review included observational studies with minimal intervention of six months, minimum sample size of 100 adolescents, written in any language, and those who have reached STROBE score greater than 70%. Results. Only seven studies met all inclusion criteria. Of these, five were pre- and postintervention and two had n > 2000 participants. Interventions were of several types, durations, and strategies for physical activity implementation. Behavior change was assessed in 43% of studies and three reported success in some way. Conclusion. Due to heterogeneity in their contents and methodologies, as well as the lack of jobs that accompany adolescents after the intervention period, one cannot draw conclusions about the actual effects of the intervention programs of physical activity on the behavior of young people.

Open-mindedness can decrease persuasion amongst adolescents: the role of self-affirmation

OBJECTIVES

Self-affirmation (e.g., by reflecting on important personal values) has been found to promote more open-minded appraisal of threatening health messages in at-risk adults. However, it is unclear how self-affirmation affects adolescents and whether it has differential effects on the impact of these messages amongst those at relatively lower and higher risk. The current study explored moderation by risk.

DESIGN

Participants were randomly assigned to either a self-affirmation or a control condition before receiving a health message concerning physical activity.

METHODS

Older adolescents (N = 125) completed a self-affirmation or control writing task before reading about the health consequences of not meeting recommendations to be physically active for at least 60 min daily. Most of the sample did not achieve these levels of activity (98%, N = 123). Consequently, the message informed these participants that - unless they changed their behaviour - they would be at higher risk of heart disease. Participants completed measures of responses to the message and behaviour-specific cognitions (e.g., self-efficacy) for meeting the recommendations.

RESULTS

For relatively inactive participants, self-affirmation was associated with increased persuasion. However, for those who were moderately active (but not meeting recommendations), those in the self-affirmation condition were less persuaded by the message.

CONCLUSIONS

Whilst self-affirmation can increase message acceptance, there are circumstances when the open-mindedness it induces may decrease persuasion. The evidence provided in this study suggests that caution may be needed when recommendations are challenging and it could be considered reasonable to be sceptical about the need to change behaviour. Statement of contribution What is already known on this subject? Self-affirmation can facilitate open-mindedness and sensitivity to whether health messages suggest high or low risk on the basis of current behaviour. What does this study add? Demonstrates that self-affirmation effects can be moderated by the extent of failure to meet recommendations. Shows that self-affirmation can be associated with less persuasion when challenging health guidelines are used.

Associations between children's independent mobility and physical activity

Background

Independent mobility describes the freedom of children to travel and play in public spaces without adult supervision. The potential benefits for children are significant such as social interactions with peers, spatial and traffic safety skills and increased physical activity. Yet, the health benefits of independent mobility, particularly on physical activity accumulation, are largely unexplored. This study aimed to investigate associations of children’s independent mobility with light, moderate-to-vigorous, and total physical activity accumulation.

Methods

In 2011 - 2012, 375 Australian children aged 8-13 years (62% girls) were recruited into a cross-sectional study. Children’s independent mobility (i.e. independent travel to school and non-school destinations, independent outdoor play) and socio-demographics were assessed through child and parent surveys. Physical activity intensity was measured objectively through an Actiheart monitor worn on four consecutive days. Associations between independent mobility and physical activity variables were analysed using generalized linear models, accounting for clustered sampling, Actiheart wear time, socio-demographics, and assessing interactions by sex.

Results

Independent travel (walking, cycling, public transport) to school and non-school destinations were not associated with light, moderate-to-vigorous and total physical activity. However, sub-analyses revealed a positive association between independent walking and cycling (excluding public transport) to school and total physical but only in boys (b = 36.03, p < 0.05). Frequent independent outdoor play (three or more days per week) was positively associated with light and total physical activity (b = 29.76, p < 0.01 and b = 32.43, p = 0.03, respectively). No significant associations were found between independent outdoor play and moderate-to-vigorous physical activity. When assessing differences by sex, the observed significant associations of independent outdoor play with light and total physical activity remained in girls but not in boys. All other associations showed no significant differences by sex.

Conclusions

Independent outdoor play may boost children’s daily physical activity levels, predominantly at light intensity. Hence, facilitating independent outdoor play could be a viable intervention strategy to enhance physical activity in children, particularly in girls. Associations between independent travel and physical activity are inconsistent overall and require further investigation.

Peak oxygen uptake and physical activity in 13- to 18-year-olds: the Young-HUNT study

PURPOSE

The present study describes the distribution of cardiorespiratory fitness (VO2peak) in a large sample of healthy adolescents and the associations between VO2peak, self-reported physical activity, and a selection of conventional markers for future cardiovascular health.

METHODS

In a substudy of the Young-HUNT study in Norway, 570 adolescents (289 girls and 281 boys) 13–18 yr. old were tested for directly measured VO2peak. Blood pressure, resting heart rate, height, weight, and waist circumference was measured by standardized procedures. Data about physical activity and pubertal development were obtained using self-administered questionnaires. General linear modeling and ANOVA were used to examine the relationships between VO2peak and age, physical activity, and cardiovascular risk factors.

RESULTS

The mean T SD VO2peak was 183.9 +/- 24.6 mL x kg(-0.67) x min(-1) (49.2 mL x kg(-0.67) x min(-1)) in girls and 235.1 +/- 35.3 mL x kg(-0.67) x min(-1) (59.5 mL x kg(-0.67) x min(-1)) in boys. Absolute VO2peak (L x min(-1)) was consistently higher in older age groups in both sexes (P trend < 0.001). VO2peak allometrically scaled to body mass (mL x kg(-0.67) x min(-1)) was similar across the age groups in girls (i.e., difference between 13- to 14-yr-olds and 17- to 18-yr-olds = -3.2 mL x kg(-0.67) x min(-1), 95% confidence interval = 3.8 to -10.1) and slightly higher in the older age groups in boys (i.e., difference between 13- to 14-yr-olds and 15- to 16-yr-olds = -31.0 mL x kg(-0.67) x min(-1), 95% confidence interval = -22.0 to -40.1). Physical activity was positively associated with VO2peak in all sex and age groups. Quartiles of VO2peak were inversely associated with resting heart rate (P trend = 0.004) in both sexes and body mass index (P trend = 0.004) and waist circumference (P trend = 0.006) in boys.

CONCLUSION

Although VO2peak was generally high across the age groups, VO2peak was higher in physically active adolescents of both sexes and physical activity in accordance with the recommended level may be sufficient to maintain or even increase VO2peak through adolescence.

Cardiovascular risk factor investigation: a pediatric issue

OBJECTIVES

To correlate cardiovascular risk factors (e.g., hypertension, obesity, hypercholesterolemia, hypertriglyceridemia, hyperglycemia, sedentariness) in childhood and adolescence with the occurrence of cardiovascular disease.

SOURCES

A systematic review of books and selected articles from PubMed, SciELO and Cochrane from 1992 to 2012.

SUMMARY OF FINDINGS

Risk factors for atherosclerosis are present in childhood, although cardiovascular disease arises during adulthood. This article presents the main studies that describe the importance of investigating the risk factors for cardiovascular diseases in childhood and their associations. Significant rates of hypertension, obesity, dyslipidemia, and sedentariness occur in children and adolescents. Blood pressure needs to be measured in childhood. An increase in arterial blood pressure in young people predicts hypertension in adulthood. The death rate from cardiovascular disease is lowest in children with lower cholesterol levels and in individuals who exercise regularly. In addition, there is a high prevalence of sedentariness in children and adolescents.

CONCLUSIONS

Studies involving the analysis of cardiovascular risk factors should always report the prevalence of these factors and their correlations during childhood because these factors are indispensable for identifying an at-risk population. The identification of risk factors in asymptomatic children could contribute to a decrease in cardiovascular disease, preventing such diseases as hypertension, obesity, and dyslipidemia from becoming the epidemics of this century.

Adolescents' physical activity habits--results from a national health survey

BACKGROUND

  The MABAT Youth National Health and Nutrition Survey was conducted in Israel by the Ministry of Health and the Center for Disease Control. This article presents results of physical activity (PA) habits in Israel, in relation to recommendations by world health organizations.

METHODS

  Participants were 6274 adolescents, grades 7-12, enrolled in a cross-sectional, representative, school-based survey. Sufficient level of PA was defined as any moderate and vigorous level of PA that adds up daily to 60 min/day. Light PA was considered to be an insufficient level of PA.

RESULTS

  Only 10.5% of the participants reported performing sufficient PA. Large gender differences were found, with 17.7% of boys versus only 4.6% of girls meeting the guidelines.

CONCLUSIONS

  Results highlight the need to develop programmes for school children in Israel to promote PA. Such programmes have been initiated in many countries that have a large percentage of adolescents with a sedentary lifestyle.

Incidence of school failure according to baseline leisure-time physical activity practice: prospective study

PURPOSE

To evaluate the prospective association between leisure-time physical activity practice at 11 years of age and incidence of school failure from 11 to 15 years of age.

METHODS

The sample comprised >4,300 adolescents followed up from birth to 15 years of age participating in a birth cohort study in Pelotas, Brazil. The incidence of school failure from age 11 to 15 years was calculated by first excluding from the analyses all subjects who experienced a school failure before 11 years of age, and then categorizing as "positive" all those who reported repeating a grade at school from 11 to 15 years of age. Leisure-time physical activity was measured using a validated questionnaire.

RESULTS

The incidence of school failure was 47.9% among boys and 38.2% among girls. Adolescents in the top quartile of leisure-time physical activity practice at 11 years of age had a higher likelihood of school failure (OR: 1.36; 95% CI: 1.06, 1.75) compared with the least active adolescents. In adjusted analyses stratified by sex, boys in the top quartile of leisure-time physical activity practice at 11 years of age were also more likely to have failed at school from age 11 to 15 years (OR: 1.60; 95% CI: 1.09, 2.33).

CONCLUSIONS

Adolescents allocating >1,000 min/wk to leisure-time physical activity were more likely to experience a school failure from 11 to 15 years of age. Although this finding does not advocate against physical activity promotion, it indicates that excess time allocated to physical activity may jeopardize school performance among adolescents.

Development of a new computer-based physical activity questionnaire to estimate habitual physical activity level in Malaysian adolescents

OBJECTIVES

To assess the validity and reproducibility of a new computer-based physical activity questionnaire (cPAQ) to estimate the habitual physical activity levels in Malaysian adolescents.

DESIGN

Cross-sectional study.

METHODS

About 425 adolescent boys and girls participated in the study. A heart rate monitor and a 7-days physical activity logbook were used as objective and subjective method criteria, respectively.

RESULTS

The mean estimated weekly total physical activity levels measured by the cPAQ were 16.5±17.5h and 13.1±16.9h for boys and girls, respectively. Analyses of the gender-specific Spearman's correlation coefficient between cPAQ and both objective and subjective method criteria showed that r values ranged from 0.54 to 0.76 (p<0.001). Method comparisons assessed by the Bland-Altman plot analysis found that the total physical activity levels, calculated from the cPAQ, fell within the mean±2 standard deviation. Reproducibility of the cPAQ was re-examined after two-weeks, showing that intra-class correlations for most PA intensity levels in boys and girls were high with a mean r value of 0.72. The effectiveness of the cPAQ showed a significantly shorter assessment time compared to the manual paper-administered questionnaire in adolescents (p<0.001) and the majority of participants (93%) accepted the overall appearance of this new cPAQ.

CONCLUSIONS

The cPAQ provides a valid and reliable method for assessing the habitual physical activity levels for the past year in Malaysian adolescents. It was also proven to be highly effective, based on duration time and its overall appearance for the adolescent participants.

Physical activity and depression in adolescents: cross-sectional findings from the ALSPAC cohort

PURPOSE

Few studies have examined the association between physical activity (PA), measured objectively, and adolescent depressive symptoms. The aim of this study was to determine whether there is an association between objective measures of PA (total PA and time spent in moderate and vigorous PA (MVPA)) and adolescent depressive symptoms.

METHODS

Data on 2,951 adolescents participating in ALSPAC were used. Depressive symptoms were measured using the self-report Mood and Feelings Questionnaire (MFQ) (short version). Measures of PA were based on accelerometry. The association between PA and MFQ scores was modelled using ordinal regression.

RESULTS

Adolescents who were more physically active (total PA or minutes of MVPA) had a reduced odds of depressive symptoms [OR(adj) total PA (tertiles): medium 0.82 (95% CI: 0.69, 0.97); high 0.69 (95% CI: 0.57, 0.83)]; OR(adj) per 15 min MVPA: 0.92 (95% CI: 0.86, 0.98). In a multivariable model including both total PA and the percentage of time spent in MVPA, total PA was associated with depressive symptoms (OR(adj) total PA (tertiles): medium 0.82 (95% CI: 0.70, 0.98); high 0.70 (95% CI: 0.58, 0.85) but the percentage of time spent in MVPA was not independently associated with depressive symptoms [OR(adj) MVPA (tertiles) medium 1.05 (95% CI: 0.88, 1.24), high 0.91 (95% CI: 0.77, 1.09)].

CONCLUSIONS

The total amount of PA undertaken was associated with adolescent depressive symptoms, but the amount of time spent in MVPA, once total PA was accounted for, was not. If confirmed in longitudinal studies and randomised controlled trials, this would have important implications for public health messages.

Benefits and environmental determinants of physical activity in children and adolescents

In this review, we identify the health benefits associated with physical activity (PA); address the physical activity and sedentary guidelines issued by public health scientists as well as children's compliance to these guidelines; discuss the importance of motor skill acquisition during early childhood; and identify different settings that contribute to physical activity participation and strategies for improving PA in these settings. Results show that regular participation in PA during childhood has numerous immediate benefits, including positive changes in adiposity, skeletal health, psychological health, and cardiorespiratory fitness. Additionally, motor skill development during early childhood may have immediate health benefits as well as long-lasting effects in adulthood. Furthermore, the benefits of PA during childhood also appear to positively influence adult health outcomes, such as increased bone mineral density. Key environmental settings that have been shown to influence children's PA behavior include child care, active commuting to and from school, school recess, school physical education, after-school programs, churches, medical settings, and the home environment. Recommendations for practitioners and researchers are discussed.

Concurrent determinants of blood pressure among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study

The aim of this study was to evaluate concurrent risk factors for high blood pressure in adolescents. This is a prospective cohort study including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. Blood pressure was measured before and after the interview, and the mean value was used in the analyses. Mean systolic blood pressure was 101.9mmHg (SD = 12.3) and mean diastolic pressure was 63.4mmHg (SD = 9.9). Adolescents with black skin had higher blood pressure than those with white skin. Mean systolic pressure among subjects in the top quartile of body mass index (BMI) was 11.6mmHg higher than among those in the lowest quartile. Mean systolic pressure among postmenarcheal girls was 5.4mmHg higher than among premenarcheal girls. Similar trends were found for diastolic arterial pressure. Our findings suggest that blood pressure control must begin already in childhood and adolescence.