Longitudinal relationship between television viewing and leisure-time physical activity during adolescence

Effects of a Physical Exercise Program and Health Advice on Sedentary Behavior of Adolescents

Sedentary behavior (SB) is a risk factor for chronic non-communicable diseases. This study aimed to assess the effects of an extracurricular physical exercise program and health advice on SB in adolescents. This was a non-randomized experimental study involving 19 adolescents divided into an intervention group (IG) and a control group (CG), aged 13-16 years from a public school in a Brazilian municipality. SB was measured using self-reports and accelerometers. The intervention included physical exercise and health advice. Repeated measures analysis of variance with a significance level of α = 5% was used. There was a time*group interaction for the subscapular fold ((pre IG = 16.30 mm vs. CG = 13.44 mm, post IG = 14.00 mm vs. CG = 15.89 mm) p = 0.001), and VO2MAX ((pre IG = 32.75 mL/kg/min vs. CG = 30.66 mL/kg/min, post IG = 35.76 mL/kg/min vs. CG = 29.28 mL/kg/min) p = 0.008). The accelerometer showed significant differences between groups in the total SB ((pre IG = 647.49 min/day vs. CG = 535.24 min/day, post IG = 614.02 min/day vs. CG = 586.97 min/day) p = 0.045), with a significant decrease in the IG. In conclusion, an extracurricular physical exercise program and health advice was effective in reducing SB in adolescents.

Physical Activity Patterns Among Adolescents in Latin America and the Caribbean Region

Background

Physical activity implies different patterns, but studies focused on physical inactivity and sedentary behaviors. This study aimed to estimate the prevalence of different physical activity patterns among adolescents in Latin America and the Caribbean region (LAC).

Methods

Pooled analysis of the most updated data of the Global School-based Student Health surveys. Age-standardized prevalence of four outcomes was estimated using information of last 7 days: physical inactivity (0 days of at least 60min/day), insufficient physical activity (<5 days of at least 60min/day), commuting physical activity (≥5 days of walking or biking to school), and sedentary behavior (≥3 hours/day of sitting time).

Results

A total of 132,071 records (33 countries) was analyzed, mean age 14.6 years, 51.2% girls. Pooled age-standardized prevalence of physical inactivity was 22.3%, greater among females (25.4%) than males (19.1%); insufficient physical activity was present in 67.7%, greater in females (73.6%) than males (61.5%); commuting physical activity was seen in 43.7%, similar between females (43.3%) and males (44.1%); and sedentary behavior was present in 43.4%, greater among females (45.4%) than males (41.3%).

Conclusions

In LAC, almost two thirds of adolescents are insufficiently physically active, ≥40% are sedentary, and ≥20% are physically inactive, more frequent among girls than boys.

The influence of specialization and the level of physical activism on leisure options for students of the Faculty of Physical Education and Sports

Leisure activities, their dynamics in ontogenesis and the way of managing the time allocated to them are a topic that is frequently researched. Purpose: to investigate students' attitudes, aiming at aspects related to forms of leisure, depending on specialization and level of physical activism, by applying a questionnaire. Material and method: The research took place in the academic year 2019-2020, on a number of 180 students of the Faculty of Physical Education and Sports in Galați. The differences for the pairs of independent specialty variables (PES / physical education and sport and PT / physical therapy), respectively physical activity (HLPA / high level of physical activity, and LLPA / low level of physical activity were analyzed, by applying the techniques of MANOVA and ANOVA calculation. Results: Multivariate analysis indicates significant effects of the physical activity variable on the items of the questionnaire for leisure budget factors, preferred leisure activities, leisure sports activities, and for the specialty variable significant effects are determined only at leisure sports activities, so the level of physical activism will generate more differences between the opinions expressed compared to the specialization of students. Univariate test results indicate significant F values (P <0.05) for a number of items, with weaker values, dominant for PT and LLPA groups. Sports activities and socializing on the internet (defining variant of young people) are at the top, so they do not exclude each other. Conclusion: the students from the PES and HLPA groups stand out through a better organization of free time, high satisfaction of its capitalization, a greater involvement in the variants of active leisure and superior socialization, and those from the PT and LLPA groups allocate more time to watching on TV and using the internet. Keywords: physical activism, specialization, questionnaire, active and passive leisure options, opinions

The Influence of Socio-Demographic Factors on the Forms of Leisure for the Students at the Faculty of Physical Education and Sports

The study investigates the influences of gender, area of origin and age stage variables and also of the interaction between them, on the free time behavior of the students at the Faculty of Physical Education and Sports from Galati. The questionnaire applied in the academic year 2019–2020 had 85 items and was structured on 4 factors: leisure budget, leisure limiting factors, preferred leisure activities, and leisure sports activities. The multivariate/MANOVA analysis showed statistically significant data for some of the analyzed items, with values of F associated with thresholds p < 0.05. The results support longer screen time for urban areas and for those <25 years and time limitation for the favorite activities of students >25 years, while reading had higher stress scores for men and students <25 years. Men tended to limit their free time working overtime and women limited their free time due to housework. Students from rural areas and men >25 years were more stressed by socializing on the internet and shopping. Financial limitations for preferred activities were higher for women and students <25 years—women read more and visited their friends more often while men had higher scores in relation to involvement in physical activities throughout the week, an aspect also reported for those <25 years. Students >25 years spent more time with their family, while those <25 years socialized more on the internet and had better scores when going out with friends. Those in urban areas did more jogging, men had better scores in relation to playing sports games, higher indicators for the satisfaction generated by sports activity, and women preferred jogging and cycling/rollerblading. Sports games and different types of fitness were the most common variants practiced at the level of the studied group. Conclusion: There was no dominant orientation of the investigated group towards forms of passive leisure and there were no cases of sedentariness, even if the use of technologies (video games, socializing on the Internet and TV) were forms of leisure often used by students.

A dual process model to predict adolescents' screen time and physical activity

OBJECTIVE

Many adolescents report a lack of physical activity (PA) and excess screen time (ST). Psychological theories aiming to understand these behaviours typically focus on predictors of only one behaviour. Yet, behaviour enactment is often a choice between options. This study sought to examine predictors of PA and ST in a single model. Variables were drawn from dual process models, which portray behaviour as the outcome of deliberative and automatic processes.

DESIGN

411 Finnish vocational school students (age 17-19) completed a survey, comprising variables from the Reasoned Action Approach (RAA) and automaticity pertaining to PA and ST, and self-reported PA and ST four weeks later.

MAIN OUTCOME MEASURES

Self-reported time spent on PA and ST and their predictors.

RESULTS

PA and ST correlated negatively (r = -.17, p = .03). Structural equation modelling revealed that intentions and habit for PA predicted PA while ST was predicted by intentions and habit for ST and negatively by PA intentions. RAA-cognitions predicted intentions.

CONCLUSION

PA and ST and their psychological predictors seem to be weakly interlinked. Future studies should assess more behaviours and related psychological influences to get a better picture of connections between different behaviours.

HighlightsPhysical activity and screen time are largely mutually exclusive classes of behaviours and might therefore be related in terms of their psychological predictors.411 adolescent vocational school students self-reported variables from the Reasoned Action Approach and behavioural automaticity related to physical activity and leisure time screen time behaviours as well as those behaviours.Structural equation modelling revealed expected within-behaviour predictions but, against expectations, no strong connections between the two behaviour classes in terms of their predictors. Only intentions to engage in physical activity negatively predicted screen time.Future research should aim to measure a wider range of mutually exclusive classes of behaviours that cover a large share of the day to uncover relations between behaviours and their respective predictors.

Electronic Games, Television, and Psychological Wellbeing of Adolescents: Mediating Role of Sleep and Physical Activity

This study investigated the associations between two common recreational screen activities and the psychological wellbeing of adolescents, and whether this association was mediated by sleep duration or physical activity frequency. This study used nationally representative cross-sectional survey data from 2946 adolescents (mean age 16.9 [0.38] years; 49% female) in the Longitudinal Study of Australian Children (LSAC). Adolescents provided information on daily time spent for each of the following: playing electronic games and watching television, time of sleep onset and wakeup, and number of days/week doing ≥60 min/day of physical activity. Psychological wellbeing was assessed by the Strengths and Difficulties Questionnaire (SDQ). Generalized estimating equations were used to examine the associations, and a contemporary multiple mediation analysis was used to examine the mediation effects. One fifth (20%) of adolescents were categorized as having poor wellbeing (SDQ total ≥17) with a significant sex difference (males: 16%; females: 24%; p < 0.001). Playing electronic games was inversely associated with psychological wellbeing for both male and female adolescents (p < 0.001). Watching television was inversely associated with psychological wellbeing for female adolescents (p < 0.001). Sleep duration and physical activity frequency were found to partially mediate the relationships between playing electronic games and the psychological wellbeing of male and female adolescents. Physical activity frequency partially mediated the association between television watching and wellbeing among female adolescents. Longitudinal studies are required to determine the causal pathway between screen-based activities and the wellbeing of adolescents, and to inform intervention strategies.

Physical Activity Levels of 1053 Omani 4th Grade Children: The Importance of Gender and Sport Team Participation in Achieving 60 Minutes of Daily Moderate-to-Vigorous Physical Activity

Sufficient daily physical activity is associated with many positive mental, physical, and societal benefits in children. Unfortunately, most children worldwide do not achieve recommended levels of daily physical activity (PA), and a majority of evidence is from Western countries and based on subjective measures. This study examined the prevalence and correlates of objectively measured PA levels among Omani children in 2017 (pre-pandemic). A two-stage cluster sampling was used to recruit the 4th grade children across five regions of Oman. A final analytic sample included 1053 children (504 boys, 549 girls) with a mean age of 9.21 years old. PA was objectively measured using a wrist-worn Polar Active Watch during three consecutive school days. Screen-based sedentary behaviors and other PA-related behaviors were subjectively measured. On average, boys were less sedentary and more active, with a greater likelihood of meeting current recommendations when compared with girls. The self-reported time spent in screen-based sedentary behaviors was relatively low for both boys and girls and was not associated with PA; however, sports team participation was associated with a greater likelihood of meeting the current recommendation. The present study provides empirical data on objectively measured PA in Omani children. The gender disparities concerning daily PA, including sports team participation, should receive further attention.

Prevalence of and factors associated with insufficient physical activity among adolescents: evidence from a nationwide survey in Bangladesh

The World Health Organization set a target of a 15% relative reduction in the prevalence of insufficient physical activity (IPA) by 2025 among adolescents and adults globally. In Bangladesh, there are no national estimates of the prevalence of IPA among adolescents. The aim of this study was to estimate the prevalence of and risk factors associated with IPA among adolescent girls and boys. Data for 4865 adolescent girls and 4907 adolescent boys, collected as a part of a National Nutrition Surveillance in 2018-19, were analysed for this study. A modified version of the Global Physical Activity Questionnaire (GPAQ) was used to collect physical activity data. The World Health Organization recommended cut-off points were used to estimate the prevalence of IPA. Bivariate and multivariable logistic regression was performed to identify factors associated with IPA. Prevalences of IPA among adolescent girls and boys were 50.3% and 29.0%, respectively, and the prevalence was significantly higher among early adolescents (10-14 years) than late adolescents (15-19 years) among both boys and girls. The IPA prevalence was highest among adolescents living in non-slum urban areas (girls: 77.7%; boys: 64.1%). For both boys and girls, younger age, non-slum urban residence, higher paternal education and increased television viewing time were significantly associated with IPA. Additionally, residing in slums was significantly associated with IPA only among the boys. Higher maternal education was associated with IPA only among the girls. This study identified several modifiable risk factors associated with IPA among adolescent boys and girls in Bangladesh. These factors should be addressed through comprehensive public health interventions to promote physical activity among adolescent girls and boys.

Structured, multifactorial randomised controlled intervention to investigate physical activity levels, body composition and diet in obese and overweight adolescents

INTRODUCTION

There has been a steep increase in the prevalence of adolescent overweight and obesity globally and in India, demonstrating that present prevention strategies are insufficient. Available evidence suggests that multifactorial interventions may improve short-term physical activity (PA), nutrition and psychological behaviour of overweight and obese adolescents but long-term follow-ups and strategies are needed. This study will investigate the effects of a structured multifactorial (school-based and family-based) intervention on adolescent obesity, compared with a single or no intervention.

METHODS AND ANALYSIS

A pragmatic, clustered randomised controlled trial with 12 weeks of interventions and 3-month, 6-month and 12-month follow-ups will be conducted at multiple participating schools in Karnataka, India. The participants will be overweight and obese male and female adolescents aged 11-16 years and will be randomly assigned by school into three groups: group A (multifactorial intervention, exercise and dietary advice); group B (exercise only); and group C (controls, no interventions). Primary outcome measures are the level of PA and body composition. Secondary outcomes are dietary change, behaviour change, food behaviours, cardiovascular and muscular fitness, quality of life, parental behaviours (physical and mental) and family functioning. Positive intervention results may reduce obesity in adolescents and promote a healthier lifestyle for students and families. A larger, culturally diverse population can benefit from a similar methodology.

ETHICS AND DISSEMINATION

The study has been approved by the Institutional Research and Ethics Committee (IEC 536-2018), Kasturba Hospital, Manipal, Udupi District, Karnataka, India. A written and verbal informed consent (supplemental material) will be provided to the participants prior to participation. On completion of the trial, the results can be communicated to adolescents and their parents on request, and will be published at national and international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

CTRI/2019/04/018834.

Comparing three screen-based sedentary behaviours' effect upon adolescents' participation in physical activity: The ESSENS study

Background

Literature focusing on the association between sedentary behaviours and physical activity has provided equivocal results and has been dominated by TV viewing as the indicator of sedentary behaviour. There is a need for more studies exploring the association between contemporary screen activities and physical activity among youth.

Methods

A cross-sectional study including 742 adolescents was conducted in 2016. Data were collected at school through an online questionnaire. Regression analyses were used to explore the association between different screen-based sedentary behaviours and participation in physical activity.

Results

The results showed that those with lower (vs higher) time spent on TV/movie streaming and electronic game playing both on weekdays and weekend days had significantly higher odds of participating in physical activity. There were no significant associations between socializing/surfing online both on weekdays and weekend days and physical activity in adjusted models.

Conclusions

TV/movie streaming and electronic game playing during both weekdays and weekend days were significantly inversely related with participating in physical activity. Initiatives aimed at reducing screen-based sedentary activities might result in favourable effects on physical activity levels among adolescents.

Psychological symptoms are associated with screen and exercise time: a cross-sectional study of Chinese adolescents

Background

Mental disorders among adolescents have become a worldwide public health problem. This study aimed to estimate the best combination of exercise time and screen time to promote the mental health of Chinese adolescents.

Methods

Participants included 7200 Chinese adolescents aged 13–18 years from six regions of China. Screen and exercise time data were collected via a self-rated questionnaire. Psychological symptoms (e.g., often feeling depressed, school-weary) were evaluated with the “Multidimensional Sub-health Questionnaire of Adolescents”. Chi-squared tests and logistic regression analysis were conducted to investigate the differences in and correlations among screen time, exercise time, and psychological symptoms.

Results

The overall detection rate of psychological symptoms among Chinese adolescents was 21.4% (22.1% for boys and 20.6% for girls). Psychological symptom detection rates were lowest among adolescents with 1–2 h/d of screen time (19.5%) and those with 30–60 min/d of exercise time (17.3%). Screen time > 2 h/d (OR = 1.38, P < 0.001) and exercise time < 30 min/d (OR = 1.62, P < 0.001) were positively correlated with psychological symptoms.

Conclusion

Screen and exercise time are associated with psychological symptoms in Chinese adolescents. A combination of 1–2 h/d of screen time and 30–60 min/d of exercise time is provided as a reference for better mental health.

Are primary care physicians ill equipped to evaluate and treat childhood physical inactivity?

Objective: To investigate primary care physician clinical practice patterns, barriers, and education surrounding pediatric physical activity (PA), and to compare practice patterns by discipline.Study design: Cross-sectional studyMethods: 4500 randomly selected pediatricians, family practice, and sports medicine physicians in the United States were surveyed (11% response rate). Main outcome measures were questionnaire answers on clinical effort, attitudes, and barriers surrounding PA, medical education in exercise science, and awareness of ICD-9 diagnostic codes pertaining to physical inactivity.Results: Approximately 15% of patient interaction time was spent on the evaluation and treatment of physical inactivity for a normal weight child. For an overweight or obese child, clinical time spent on PA almost doubles. Regardless of weight, sports medicine physicians spent significantly more time on the evaluation of physical activity compared to family/internal medicine physicians and pediatricians. Mean percentage of time family/internal medicine physicians spent on PA evaluation and treatment was consistently less than sports medicine physicians, and consistently more than pediatricians. Most physicians strongly agreed that PA assessment and treatment are important for disease prevention; only 28% had ever made the diagnosis of childhood physical inactivity. Limited clinical time was identified as a primary barrier to diagnosing childhood physical inactivity. Eighty-five percent of respondents were unaware of ICD-9 codes for reimbursement of PA evaluation. Eighty-one percent reported a paucity of exercise science education in medical school.Conclusion: While physicians report that PA evaluation is important in practice, behavior patterns surrounding time evaluating PA and treating childhood physical inactivity are discrepant. Pediatricians showed less favorable attitudes and effort surrounding PA compared to other primary care disciplines. The majority of physicians are unaware of physical inactivity diagnostic codes, have never made the diagnosis of childhood physical inactivity, and may not be receiving basic pediatric exercise science training required for evaluating and treating childhood physical inactivity.

The Digital Media Environment and Cardiovascular Risk in Children

Children today are exposed to multiple forms of digital media including traditional (eg, televisions, computers) and newer mobile devices (eg, smartphones, tablets, etc). As the digital media environment evolves, it is important that health care providers and policymakers adapt to develop, implement, and evaluate strategies to ameliorate its effects on health. In this article we provide an overview of the literature on the relationship between the digital media environment and cardiovascular risk factors in childhood. Existing evidence on the relationship between digital media environment and cardiovascular risk in infants, children, and youth are reported. Potential mechanisms underpinning the relationship between the digital media environment and cardiovascular disease risk in children such as the displacement of movement behaviours, food and beverage marketing to children, and eating while viewing were explored. National and international guidelines aimed at addressing the digital media environment are highlighted, and suggestions for future research and guideline development are provided. Action-oriented professional recommendations for health care providers, families, and children are urgently needed. As the prevalence of screen use in childhood continues to exceed those of past generations, concern about the effects and strategies to reduce harm including cardiovascular outcomes must remain a top public health priority.

Associations among Body Mass Index, sedentary behavior, physical activity, and academic performance in schoolchildren

BACKGROUND

Physical inactivity and sedentary behavior are common among middle and high school grade children. This study aimed to determine the relationship among Body Mass Index (BMI), sedentary behavior, physical activity (PA), and overall academic performance of students.

METHODS

This is a cross sectional study; 357 students of mean age 12.65±1.68 years were enrolled. PA was subjectively assessed using the Physical Activity Questionnaire for Children (PAQ-C) and Godin Leisure-Time Exercise Questionnaire (GLTEQ). Sedentary behavior was assessed as hours spent on watching television, playing video games, computer use, and homework. Grade point average (GPA) was calculated to determine their overall academic performance. Participants were divided into two groups based on their GPA. Independent t-test was used to analyze BMI, sedentary time, and PA between the groups. Correlation analysis was performed to determine the associations among BMI, sedentary time, physical activity, and academic grades.

RESULTS

There was no significant difference in BMI and the level of PA between the two groups. However, significant differences were observed in sedentary time (ST) spent watching television (P=0.04), total screen time (P=0.02), and total ST (P=0.002). There were weak negative correlations among BMI (r=-0.14, P<0.05), total screen time (r=-0.12, P<0.05), and academic scores; however, there was no association with any PA measures.

CONCLUSIONS

A weak correlation was noted between BMI and sedentary characteristics, with respect to academic performance. As academic performance is negatively associated with body mass index and screen time, public health interventions are needed to reduce their time spent on leisure time sedentary activity, watching television, and computer use.

Cross-Cultural Variation in BMI, Sedentary Behavior, and Physical Activity in International School Girls Residing in Saudi Arabia

Background: The current study was done to assess the cross-cultural difference in physical activity and sedentary behavior among girls from culturally, environmentally, and geographically diverse countries residing in Saudi Arabia. Methods: This was a comparative cross-sectional study conducted among expatriate girls (N = 275), aged 9–16 years. Participants were from India (n = 65), Pakistan (n = 88), Egypt (n = 50), Sudan (n = 49), and other nationals (n = 23). They were randomly selected from different schools in Riyadh and their Body Mass Index (BMI) and screen time was assessed. Physical activity (PA) and leisure-time activity was assessed using Physical Activity Questionnaire for Older Children (PAQ-C) and the Godin-Shephard Leisure-Time Exercise Questionnaire (GSLTPAQ) respectively. Results: Out of 275, 65.8% were active and 34.2% were insufficiently active as per the GSLTPAQ, and half of them were moderately active and only 22.2% were extremely active as per PAQ-C. No statistical significant differences in their BMI status, screen time, or the levels of PA among expatriate girls. Conclusions: This study shows that the expatriate female school children in Saudi Arabia demonstrated a similar pattern in their BMI, sedentary time spent, and PA levels.

Manual Dexterity is not Related to Media Viewing but is Related to Perceptual Bias in School-Age Children

Although the media can have both negative and positive effects on children’s cognitive and motor functions, its influence on their perceptual bias and manual dexterity is unclear. Thus, we investigated the association between media viewing time, media preference level, perceptual bias, and manual dexterity in 100 school-aged children. Questionnaires completed by children and their parents were used to ascertain media viewing time and preference levels. Perceptual bias and manual dexterity were measured using the visual-tactile temporal order judgment task and Movement Assessment Battery for Children—2nd edition, respectively. There were significant positive correlations between age and media viewing time and between media viewing time and media preference level. There was also a significant negative correlation between visual bias and manual dexterity. Hierarchical multiple regression analysis revealed that increasing visual bias was a significant predictor of decreasing manual dexterity. Further, children with low manual dexterity showed significant visual bias compared to those with high manual dexterity, when matched for age and gender. The present results demonstrated that, in school-aged children, although viewing media was not associated with perceptual bias and manual dexterity, there was a significant association between perceptual bias and manual dexterity.

Combined Patterns Of Physical Activity And Screen-Related Sedentary Behavior Among Chinese Adolescents And Their Correlations With Depression, Anxiety And Self-Injurious Behaviors

Background and purpose

There are increasing concern about independent associations between physical activity, screen-based sedentary behavior (SSB), and psychological problems, but only a few studies have attempted to explore combined patterns of physical activity and SSB in adolescents and their correlations with psychological problems. This study was aimed at identifying combined patterns of moderate-to-vigorous physical activity (MVPA) and SSB and examining the prevalence of different combined patterns and their correlations with depression, anxiety, and self-injurious behavior among Chinese adolescents.

Methods

Junior and senior high school students (N = 13,659; mean age 15.18±1.89) were recruited. Latent class analysis was conducted to identify combined patterns of MVPA and SSB. Associations between subgroups of MVPA and SSB and socio-demographic characteristics were assessed by logistic regression. Their correlation with depression, anxiety, and self-injurious behaviors was assessed by analysis of variance with analysis stratified by gender.

Results

Four latent classes were identified: high MVPA/low SSB group (64.7%), low MVPA/low SSB (26.7%), low MVPA/high SSB (4.8%), and low MVPA/moderate SSB (3.9%). Generally, the high MVPA/low SSB class was a relatively healthy group. The low MVPA/high SSB class was at risk of enduring depression, anxiety, and self-injurious behavior, with boys being more at risk than girls.

Conclusion

Four latent subgroups of MVPA and SSB were identified in Chinese adolescents. The findings highlight the potential role of concurrent MVPA and SSB, with gender-specific characteristics in the primary prevention of adolescent depression, anxiety, and self-injurious behaviors.

Activity-related behavior typologies in youth: a systematic review

BACKGROUND

Clusters of adolescents differentiated by patterns of physical activity and sedentary behavior (activity-related typologies) are common. Understanding both the characteristics of adolescents and modifiable correlates of these typologies, can help to develop interventions for those most at risk. This systematic review aimed to synthesize the socio-demographic characteristics and modifiable correlates of activity-related behavioral typologies among adolescents.

METHODS

A systematic search of seven electronic databases was conducted to identify quantitative studies using person-oriented statistical approaches to identify activity-related behavioral typologies among 12-18 year-olds. This systematic review was registered in Prospero (registration number: CRD42016046879).

RESULTS

Thirty-six studies met the inclusion criteria and were classified according to three sub-themes based on behaviors included in the typologies (1. physical activity and sedentary behavior only; 2. physical activity, sedentary behavior and risk-related behaviors; 3. physical activity, sedentary behavior and diet). Studies were mostly cross-sectional and relied on self-report measures. Methods were considerably heterogeneous, however results revealed some consistency in typologies within specific groups. For example, typologies characterized by unhealthy behavior patterns (e.g., characterized by physical inactivity, high sedentary behavior and poor diet or high risk-related behaviors) comprised more older adolescents. With the exception of socio-demographics (age, sex, body mass index and socio-economic status), very few correlates have been studied to date (mostly school-related behavioral factors and intrapersonal influences), with evidence largely from typologies comprised of physical activity, sedentary behavior and diet.

CONCLUSIONS

More research is needed to assess a range of modifiable correlates associated with activity-related behavior typologies among adolescents. This will allow for more targeted interventions, to achieve long-lasting, positive behavior change in adolescent populations.

Cross-sectional and longitudinal association of sports participation, media consumption and motor competence in youth

The beneficial associations of physical activity (PA) and sports with motor competence have been well documented. Similarly, high media time has been associated with poor motor competence. Limited information, however, is available on the combined effects of sport participation and media consumption on motor competence. The present study followed 213 Austrian middle-school students (57% male; age at baseline: 10.4 ± 0.6 years) over a 4-year period. Annual assessments included the German Motor Test 6-18, along with self-reported participation in club sports, time spent watching TV and using the computer. There were no interaction effects between sports participation and media time on motor competence. Club sports participation, however, was associated with higher motor competence, while there was an inverse association between media time and motor competence. Further, motor competence affected future participation in club sports while club sports had limited effects on subsequent motor development. High media time, on the other hand, impaired subsequent motor development, while effects of motor competence on media time were limited. Taken together, these results emphasize the importance of motor competence in the facilitation of sports participation during adolescence. Accordingly, a wide variety of movement experiences should be provided at young ages to promote motor development. In addition, the detrimental effects of media time on motor competence warrant that sedentary behaviors are targeted separately, particularly in youth not participating in sports.

Stability and bidirectional relationship between physical activity and sedentary behaviours in Brazilian adolescents: Longitudinal findings from a school cohort study

Purpose

We investigated the stability, correlations and bidirectional relationship of light physical activities (PA), moderate and vigorous PA (MVPA), television viewing (TV) and video game/computer use (VG) in Brazilian adolescents.

Methods

Adolescent Nutritional Assessment Longitudinal Study-ELANA is a middle school cohort study conducted in Rio de Janeiro-Brazil in 2010–2012. Self-reported data on PA (International Physical Activity Questionnaire- IPAQ) and screen activities were obtained from 810 adolescents (mean ages of 10.9 years old (SD 0.78) for girls; 11 years old (SD 0.85) for boys) to perform autoregressive cross-lagged structural equation models in two time points for PA and three time points for screen activities.

Results

There was no significant stability of light PA and MVPA for boys and girls. Moderate stability of screen activities were found for both genders, with a significant coefficient of TV for boys (T1-T2:0.29; T2-T3:0.27 p<0.001); and VG for boys (T1-T2:0.33; T2-T3:0.35 p<0.001) and girls (T1-T2: 0.26; T2-T3:0.37 p<0.01). Significant lagged effects were obtained only among girls: light PA had effect on VG (-0.10 p<0.01), as well as in the opposite direction of TV on light PA (-0.03 p<0.01) and TV on MVPA (-0.11 p<0.01).

Conclusion

The light PA, MVPA and screen activities (among girls) did not demonstrate stability over time. A warning scenario was suggested by the stability of high amounts of screen activities among boys over time. Screen activities had bidirectional association with light PA and MVPA among girls over time.

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.

US adolescents at risk for not meeting physical activity recommendations by season

BACKGROUND

We sought to identify regional and seasonal variation in not meeting physical activity (PA) recommendations of ≥60 min a day of moderate-to-vigorous PA (MVPA) and 3 h of vigorous PA per week (VPA) in a longitudinal cohort of United States (US) adolescents.

METHODS

Participants in the Growing Up Today Study 2, a prospective study of 10,918 adolescents, self-reported season-specific weekly hours of MVPA and VPA from 2004 through 2011. To assess variation in PA by climate, we grouped the contiguous US into nine climatically consistent geographic regions. We also examined MVPA and VPA by season, sex, ethnicity, weight status, and age group.

RESULTS

The majority (85%) of adolescents did not meet the MVPA recommendation, and 91% did not meet the VPA recommendation, for one or more seasons over the four study years. Across all climate regions, adolescents were two times more likely to not meet the MVPA recommendation during the winter compared to summer (odds ratio 2.02, 95% confidence interval: 1.96-2.08).

CONCLUSION

Regardless of climate region, gender, ethnicity, or age group, adolescents were more likely not to meet MVPA or VPA recommendations in the winter than the summer. Adolescents may benefit from interventions aimed at increasing PA in the winter.

Developmental Trends and Determinants of Physical Activity From Adolescence to Adulthood Differ by Ethnicity/Race and Sex

BACKGROUND

Interventions to raise population physical activity generally show modest effects; one possible reason is that trends and determinants of moderate to vigorous physical activity (MVPA) differ between population subgroups. This study examined differences in trends and determinants of reported MVPA by ethnicity/race and sex in a 15-year longitudinal study.

METHODS

Participants (n = 2092) in the Project Eating and Activity in Teens and Young Adults study were surveyed on MVPA behavior and potential determinants from adolescence to young adulthood. Generalized estimating equations were used to model age trends in MVPA and associations with determinants.

RESULTS

Mean MVPA declined by 2.1 hours per week over 15 years of follow-up from adolescence to young adulthood. Asian males reported the lowest levels of MVPA at each age. Nonwhite females reported less MVPA than white females at each age. The association of body mass index (BMI) with MVPA differed by sex and ethnicity/race. Asian males and females showed lower levels of MVPA at both low and high BMI.

CONCLUSIONS

Interventions to increase MVPA may need to begin earlier among Asian men and nonwhite women than among other groups. Asian adolescents with lower BMI show lower MVPA and may benefit from additional intervention efforts compared with Asian adolescents with normal BMI.

Application of the transtheoretical model to sedentary behaviors and its association with physical activity status

BACKGROUND

The Transtheoretical Model (TTM) is a successful framework for guiding behavior change programs for several health behaviors, yet its application to reduce of sedentary behavior has been neglected. In addition, no data exist regarding the association between determinants of sedentary behaviors based on the TTM and physical activity behavior. The purpose of this study was to investigate college students' stages of motivational readiness to avoid sedentary behaviors and relevant psychological determinants using newly developed TTM questionnaires and to identify the association between current physical activity and sedentary behaviors based on TTM constructs.

METHODS

Data were obtained from 225 college students enrolled in health education and physical education courses. Participants completed a package of questionnaires including validated TTM, physical activity and sitting time questionnaires. Participants also wore an accelerometer for seven consecutive days. MANOVAs were conducted to determine mean differences in psychological constructs across the TTM stages, and Chi-square tests and Spearman correlation were used to evaluate the associations between current physical activity and sedentary behavior.

RESULTS

A majority of the participants were in the sedentary stages, and men and women differed in proportion of individuals in the stages (78.0% vs. 68.1%, respectively). The gender difference was also found in use of the processes of change. In general, the mean scores of the TTM constructs increased as the stages progressed. No significant associations were found between the TTM constructs for sedentary behavior and current physical activity levels (p>0.05).

CONCLUSIONS

A high proportion of college students were in sedentary stages regardless of physical activity levels, but different distributions in men and women. Participants in earlier stages were less likely to utilize the TTM constructs to reduce sedentary behaviors than those in later stages. A lack of association between physical activity and the psychological determinants of sedentary behavior was found.

Sedentary Behavior During School Recess in Southern Brazil

The aim of this study was to assess sedentary behavior during school recess in Brazilian boys and girls. The study included 455 students (233 boys and 222 girls), aged 8 to 17 years, enrolled in a public school in the city of Londrina, Brazil. All data was collected using questionnaires. Logistic regression with odds ratio and confidence interval (95%) was used to measure the relationship between sedentary behavior and sex, age, weight, screen time, and economic status. There was a high prevalence (40.7%) of sedentary behavior in this sample, with girls (aged 8 to 17 years) more likely than boys (54.5% vs. 27.5%, respectively) and older students (13-17 years) more likely than younger students (8-12 years) to engage in sedentary behavior (49.6% vs. 30.1%, respectively). These findings, and their broad implications for health and for interventions to increase physical activity, are discussed in light of past literature.

Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood

In adults, physical activity and exercise training are associated with reduced cardiovascular morbidity and mortality, a reduced likelihood of developing adverse cardiovascular risk factors, and improved insulin sensitivity. In childhood, participation in appropriate physical activity may prevent the development of cardiovascular risk factors in the future and complement treatment of existing cardiovascular risk factors, including hypertension, dyslipidemia, and overweight. Exercise in children can also significantly improve insulin sensitivity independent of weight loss. These e fects are mediated in overweight children by increases in lean body mass relative to fat mass and associated improvements in inflammatory mediators, endothelial function, and the associated adverse hormonal milieu.

Associations among measures of energy balance related behaviors and psychosocial determinants in urban upper elementary school children

BACKGROUND

Childhood obesity prevention is a pressing issue. Understanding the relationships among eating and physical activity behaviors and potential psychosocial determinants of behavior will help us design more effective interventions. This study aimed to examine such relationships in a large sample of urban elementary school children.

METHODS

Fifth grade students in 20 recruited New York City public schools completed a validated questionnaire on six "do more" (fruits and vegetables and physical activity) and "do less" (sweetened beverages, processed packaged snacks, fast food and sedentary behavior) energy balance related behaviors (EBRBs) and psychosocial determinants of behavior from social cognitive and self-determination theories. Correlations among behaviors and hierarchical linear model analyses of the relationship between psychosocial determinants and behaviors were conducted for those with complete data (n = 952).

RESULTS

The "do more" and the "do less" behaviors were significantly correlated within categories (p < 0.01). "Do more" food-related behaviors were correlated with physical activity but so were sports drinks, while the "do less" food-related behaviors tended to be correlated to sedentary behavior (p < 0.01). "Do more" behaviors were associated with self-efficacy and habit strength, and "do less" behaviors with outcome expectations, self-efficacy, habit strength, and behavioral intention.

CONCLUSIONS

Interventions can address the healthy and less healthy clusters of behaviors together, focusing on strategies to enhance their self-efficacy and habit strength for the "do more" behaviors and outcome expectations to motivate intention to choose fewer "do less" behaviors, along with enhancing self-efficacy and habit. Research can examine these determinants as potential mediators of change in intervention.

Changes in physical activity and screen time related to psychological well-being in early adolescence: findings from longitudinal study ELANA

Background

Psychological well-being influences health behaviours differently in adolescent boys and girls. We evaluated the role of psychological well-being in early adolescence in the onset and persistence of insufficient physical activity and exceeding recommended screen time, depending on gender.

Methods

This work derives from a cohort study called Longitudinal Study of Adolescent Nutritional Assessment conducted among elementary school students from two public and four private schools in Rio de Janeiro, Brazil from 2010–2013. We analysed data from 2010 and 2012 from 526 adolescents. Physical activity was evaluated using the International Physical Activity Questionnaire. Those who performed less than 60 min per day of moderate to vigorous physical activity (MVPA) were classified as insufficiently active. Screen time was evaluated based on daily time spent in front of television, video games, and computers. Those who had 4 h or more screen time per day were classified as exceeding the recommended time. Psychological well-being was assessed using the psychological domain of the KIDSCREEN 27 questionnaire. Linear regression was used to estimate coefficient (β) and r² values for continuous variables. Relative risks (RR) and confidence intervals (95 % CI) for onset and persistence of insufficient activity and exceeding recommended screen time were estimated with Poisson regression models.

Results

Among girls, linear regression analyses showed a significant inverse association between psychological well-being and screen minutes per day at T2 (r² = 0.049/β = −3.81 (95 % CI −7.0, −0.9)), as well as an association between poor psychological well-being and onset of exceeding recommended screen time in categorical analyses (RR crude: 1.3; CI 95 % 1.1, 1.7; RR adjusted: 1.3; CI 95 % 1.0, 1.6). For boys, an association was found between psychological well-being and onset of insufficient activity 2 years later (RR crude: 1.3; CI 95 % 1.2, 1.4; RR adjusted: 1.2; CI 95 % 1.1, 1.4).

Conclusion

Adolescence is crucial for the development of unhealthy behaviours related to psychological well-being status in the context of a middle-income country. Gender differences are important because poor psychological well-being seems to affect sedentary behaviour in girls more than in boys, and predicts insufficient activity among boys.

Physical activity and screen time in children and adolescents in a medium size town in the South of Brazil

Objective:

To analyze the associations between sex and age with behaviour related to physical activity practice and sedentary behaviour in children and adolescents.

Methods:

A cross-sectional study with 480 (236 boys) subjects enrolled in a public school in the city of Londrina, in the south of Brazil, aged 8–17 years. Measures of physical activity, sports practice and screen times were obtained using the Physical Activity Questionnaire for Older Children. The Mann–Whitney U test was used to compare variables between boys and girls. The Chi squared test was used for categorical analysis and Poisson regression was used to identify prevalence.

Results:

Girls (69.6%; PR=1.05 [0.99–1.12]) spent more time with sedentary behaviour than boys (62.2%). Boys (80%; PR=0.95 [0.92–0.98]) were more physically active than girls (91%). Older students aged 13–17 showed a higher prevalence of physical inactivity (91.4%; PR=1.06 [1.02–1.10]) and time spent with sedentary behaviour of ≥2h/day (71.8%; PR=0.91 [0.85–0.97]) when compared to younger peers aged 8–12 (78.7 and 58.5%, respectively).

Conclusions:

The prevalence of physical inactivity was higher in girls. Older students spent more screen time in comparison to younger students.

Toddlers' Fine Motor Milestone Achievement Is Associated with Early Touchscreen Scrolling

Touchscreen technologies provide an intuitive and attractive source of sensory/cognitive stimulation for young children. Despite fears that usage may have a negative impact on toddlers’ cognitive development, empirical evidence is lacking. The current study presents results from the UK Toddler Attentional Behaviours and LEarning with Touchscreens (TABLET) project, examining the association between toddlers’ touchscreen use and the attainment of developmental milestones. Data were gathered in an online survey of 715 parents of 6- to 36-month-olds to address two research questions: (1) How does touchscreen use change from 6 to 36 months? (2) In toddlers (19–36 months, i.e., above the median age, n = 366), how does retrospectively reported age of first touchscreen usage relate to gross motor (i.e., walking), fine motor (i.e., stacking blocks), and language (i.e., producing two-word utterances) milestones? In our sample, the proportion of children using touchscreens, as well as the average daily usage time, increased with age (youngest quartile, 6–11 months: 51.22% users, 8.53 min per day; oldest quartile, 26–36 months: 92.05% users, average use of 43.95 min per day). In toddlers, aged 19–36 months, age of first touchscreen use was significantly associated with fine motor (stacking blocks), p = 0.03, after controlling for covariates age, sex, mother’s education (a proxy for socioeconomic status) as well as age of early fine motor milestone achievement (pincer grip). This effect was only present for active scrolling of the touchscreen p = 0.04, not for video watching. No significant relationships were found between touchscreen use and either gross motor or language milestones. Touchscreen use increases rapidly over the first 3 years of life. In the current study, we find no evidence to support a negative association between the age of first touchscreen usage and developmental milestones. Indeed, earlier touchscreen use, specifically scrolling of the screen, was associated with earlier fine motor achievement. Future longitudinal studies are required to elucidate the temporal order and mechanisms of this association, and to examine the impact of touchscreen use on other, more fine-grained, measures of behavioral, cognitive, and neural development.

Impact of physical exercise/activity on vascular structure and inflammation in pediatric populations: A literature review

PURPOSE

To describe the effects of physical exercise/activity on the vascular architecture of children and adolescents, as well as to identify the effects of inflammation and sedentary behaviors on this relationship.

METHODS

Potentially relevant articles were identified in the databases MEDLINE and PubMed covering the period from 2000 to 2015. No language restrictions were applied.

RESULTS

Thirteen articles were found that included obese boys and girls in their samples (aged 9-19). Six interventional studies assessed inflammation and in five of these, physical exercise decreased inflammation. In 10 studies, vascular architecture was affected by physical exercise/activity.

CONCLUSIONS

The impact of physical exercise on vascular architecture and inflammation seems relevant, but has been mainly investigated in obese groups.

PRACTICAL IMPLICATIONS

Health professionals should act together in organized interventions in schools, targeting the promotion of higher physical activity levels in children and adolescents.

Leisure Time Physical Inactivity and Sedentary Behaviour and Lifestyle Correlates among Students Aged 13-15 in the Association of Southeast Asian Nations (ASEAN) Member States, 2007-2013

The aim of this study was to examine the relationship between self-reported leisure time physical inactivity frequency and sedentary behaviour and lifestyle correlates among school children in the Association of Southeast Asian Nations (ASEAN) region. The analysis included 30,284 school children aged 13–15 years from seven ASEAN countries that participated in the Global School-based Student Health Survey (GSHS) between 2007 and 2013. The measure asked about overall physical activity, walking or biking to school, and on time spent sitting. Overall, the prevalence of physical inactivity was 80.4%, ranging from 74.8% in Myanmar to 90.7% in Cambodia and sedentary behaviour 33.0%, ranging from 10.5% in Cambodia and Myanmar to 42.7% in Malaysia. In multivariate logistic regression, not walking or biking to school, not attending physical education classes, inadequate vegetable consumption and lack of protective factors (peer and parental or guardian support) were associated with physical inactivity, and older age (14 and 15 years old), coming from an upper middle income country, being overweight or obese, attending physical education classes, alcohol use, loneliness, peer support and lack of parental or guardian supervision were associated with sedentary behaviour. In boys, lower socioeconomic status (in the form of having experienced hunger) and coming from a low income or lower middle income country were additionally associated with physical inactivity, and in girls, higher socioeconomic status, not walking or biking to school and being bullied were additionally associated with sedentary behaviour. In conclusion, a very high prevalence of leisure physical inactivity and sedentary behaviour among school going adolescents in ASEAN was found and several factors identified that may inform physical activity promotion programmes in school-going adolescents in ASEAN.

Screen-based sedentary behavior and associations with functional strength in 6-15 year-old children in the United States

BACKGROUND

Physical strength is associated with improved health outcomes in children. Heavier children tend to have lower functional strength and mobility. Physical activity can increase children's strength, but it is unknown how different types of electronic media use impact physical strength.

METHODS

Data from the NHANES National Youth Fitness Survey (NNYFS) from children ages 6-15 were analyzed in this study. Regression models were conducted to determine if screen-based sedentary behaviors (television viewing time, computer/video game time) were associated with strength measures (grip, leg extensions, modified pull-ups, plank) while controlling for potential confounders including child age, sex, BMI z-score, and days per week with 60+ minutes of physical activity. Grip strength and leg extensions divided by body weight were analyzed to provide measures of relative strength together with pull-ups and plank, which require lifting the body.

RESULTS

The results from the regression models showed the hypothesized inverse association between TV time and all strength measures. Computer time was only significantly inversely associated with the ability to do one or more pull-ups.

CONCLUSIONS

This study shows that television viewing, but not computer/videogames, is inversely associated with measures of child strength while controlling for child characteristics and physical activity. These findings suggest that "screen time" may not be a unified construct with respect to strength outcomes and that further exploration of the potential benefits of reducing television time on children's strength and related mobility is needed.

Dose-response association of screen time-based sedentary behaviour in children and adolescents and depression: a meta-analysis of observational studies

Background

Depression represents a growing public health burden. Understanding how screen time (ST) in juveniles may be associated with risk of depression is critical for the development of prevention and intervention strategies. Findings from studies addressing this question thus far have been inconsistent. Therefore, we conducted a comprehensive systematic review and meta-analysis of data related to this question.

Methods

The meta-analysis was conducted in accordance with the PRISMA guideline. We searched the electronic databases of PubMed, Web of Science and EBSCO systematically (up to 6 May 2015). OR was adopted as the pooled measurement of association between ST and depression risk. Dose–response was estimated by a generalised least squares trend estimation.

Results

Twelve cross-sectional studies and four longitudinal studies (including 1 cohort study) involving a total of 127 714 participants were included. Overall, higher ST in preadolescent children and adolescents was significantly associated with a higher risk of depression (OR=1.12; 95% CI 1.03 to 1.22). Screen type, age, population and reference category acted as significant moderators. Compared with the reference group who had no ST, there was a non-linear dose–response association of ST with a decreasing risk of depression at ST<2 h/day, with the lowest risk being observed for 1 h/day (OR=0.88; 95% CI 0.84 to 0.93).

Conclusions

Our meta-analysis suggests that ST in children and adolescents is associated with depression risk in a non-linear dose–response manner.

Association between electronic equipment in the bedroom and sedentary lifestyle, physical activity, and body mass index of children

OBJECTIVE

To describe the association between electronic devices in the bedroom with sedentary time and physical activity, both assessed by accelerometry, in addition to body mass index in children from São Caetano do Sul.

METHODS

The sample consisted of 441 children. The presence of electronic equipment (television, personal computer, and videogames) in the bedroom was assessed by a questionnaire. For seven consecutive days, children used an accelerometer to objectively monitor the sedentary time and moderate-to-vigorous physical activity. Body mass index was categorized as suggested by the World Health Organization.

RESULTS

Overall, 73.9%, 54.2% and 42.8% of children had TV, computer, and videogames in the bedroom, respectively, and spent an average of 500.7 and 59.1 min/day of sedentary time and moderate-to-vigorous physical activity. Of the children, 45.3% were overweight/obese. Girls with a computer in the bedroom (45 min/day) performed less moderate-to-vigorous physical activity than those without it (51.4 min/day). Similar results were observed for body mass index in boys. Moderate-to-vigorous physical activity was higher and body mass index was lower in children that had no electronic equipment in the bedroom. Presence of a computer (β=-4.798) and the combination TV+computer (β=-3.233) were negatively associated with moderate-to-vigorous physical activity. Videogames and the combinations with two or three electronic devices were positively associated with body mass index. Sedentary time was not associated with electronic equipment.

CONCLUSION

Electronic equipment in the children's bedroom can negatively affect moderate-to-vigorous physical activity and body mass index regardless of gender, school, and annual family income, which can contribute to physical inactivity and childhood obesity.

Concurrent Associations of Physical Activity and Screen-Based Sedentary Behavior on Obesity Among US Adolescents: A Latent Class Analysis

Background

Independent associations of physical activity (PA) and sedentary behavior (SB) with obesity are well documented. However, little is known about the combined associations of these behaviors with obesity in adolescents. The present study examines the prevalence of concurrent levels of PA and SB, and their associations with obesity among US adolescents.

Methods

Data from a total of 12 081 adolescents who participated in the Youth Risk Behaviors Survey during 2012–2013 were analyzed. A latent class analysis was performed to identify latent subgroups with varying combined levels of subjectively measured PA and screen-based SB. Follow-up analysis examined the changes in the likelihood of being obese as determined by the Center for Disease Control and Prevention Growth Chart between latent subgroups.

Results

Four latent subgroups with varying combined levels of PA and SB were identified across gender. The likelihood of being obese was significantly greater for the subgroups featuring either or both Low PA or High SB when compared with High PA/Low SB across genders (odds ratio [OR] ranges, 2.1–2.7 for males and 9.6–23.5 for females). Low PA/High SB showed the greater likelihood of being obese compared to subgroups featuring either or both High PA and Low SB (OR ranges, 2.2–23.5) for female adolescents only.

Conclusions

The findings imply that promoting sufficient levels of PA while reducing SB should be encouraged in order to reduce obesity risk among adolescents, particularly for males. The risk of obesity for female adolescents can be reduced by engaging in either high levels of PA or low levels of SB.

Sex-specific genetic effects in physical activity: results from a quantitative genetic analysis

BACKGROUND

The objective of this study is to present a model to estimate sex-specific genetic effects on physical activity (PA) levels and sedentary behaviour (SB) using three generation families.

METHODS

The sample consisted of 100 families covering three generations from Portugal. PA and SB were assessed via the International Physical Activity Questionnaire short form (IPAQ-SF). Sex-specific effects were assessed by genotype-by-sex interaction (GSI) models and sex-specific heritabilities. GSI effects and heterogeneity were tested in the residual environmental variance. SPSS 17 and SOLAR v. 4.1 were used in all computations.

RESULTS

The genetic component for PA and SB domains varied from low to moderate (11% to 46%), when analyzing both genders combined. We found GSI effects for vigorous PA (p = 0.02) and time spent watching television (WT) (p < 0.001) that showed significantly higher additive genetic variance estimates in males. The heterogeneity in the residual environmental variance was significant for moderate PA (p = 0.02), vigorous PA (p = 0.006) and total PA (p = 0.001). Sex-specific heritability estimates were significantly higher in males only for WT, with a male-to-female difference in heritability of 42.5 (95% confidence interval: 6.4, 70.4).

CONCLUSIONS

Low to moderate genetic effects on PA and SB traits were found. Results from the GSI model show that there are sex-specific effects in two phenotypes, VPA and WT with a stronger genetic influence in males.

Developmental trajectories of physical activity and television viewing during adolescence among girls: National Growth and Health Cohort Study

Background

Analytic methodology for investigating physical activity patterns over time has been limited. The aim of this study was to demonstrate the group-based trajectory analysis process for identifying developmental physical activity (PA) and television (TV) viewing trajectories and the risk factor of PA trajectories, and for examining a relationship between PA and TV viewing trajectories among adolescent girls.

Methods

Secondary analysis was conducted using the National Growth and Health Study (NGHS) dataset. The NGHS administered the Habitual Activity Questionnaire and TV viewing questionnaire to White and Black girls at age 10, 12, 14, 16, 17, 18, and 19 years. Group-based trajectory analyses were conducted to identify distinct PA trajectories. Race was chosen to present an example of the risk factor analysis and was added as a predictor in the trajectory model. Dual-trajectory analysis was conducted to estimate probabilities of TV viewing trajectory groups conditional on the PA trajectory groups.

Results

A total of 2,155 girls (52 % Black) were included in the data analysis. We identified four PA trajectories: substantially decreasing from high PA (PA group 1, 9.4 %), maintaining moderate PA (PA group 2, 31.6 %), maintaining high PA (PA group 3, 5.8 %), and decreasing from moderate PA (PA group 4, 53.2 %). A significantly lower proportion of Black girls had high PA levels at baseline and maintained their baseline PA than White girls. Most girls who were classified as maintaining high PA (88 %) were also classified as decreasing TV viewing.

Conclusions

A group-based trajectory approach provides new insights about the patterns of maintaining moderate or high levels of PA that exist among adolescent girls. However, a lower proportion of Black girls followed the maintenance patterns than White girls. The behavioral development of PA and TV viewing may be intertwined among adolescent girls.

Developmental Trajectories of Physical Activity, Sports, and Television Viewing During Childhood to Young Adulthood: Iowa Bone Development Study

IMPORTANCE

The diverse developmental patterns of obesogenic behaviors during childhood and adolescence can be better understood by using new analytic approaches to assess the heterogeneity in variation during growth and development and to map the clustering of behavior patterns.

OBJECTIVES

To identify distinct trajectories of daily time spent in moderate- to vigorous-intensity physical activity (MVPA) from ages 5 to 19 years and to examine the associations of MVPA trajectories with sports participation and television viewing trajectories.

DESIGN, SETTING, AND PARTICIPANTS

Cohort members in the prospective population-based Iowa Bone Development Study participated in MVPA assessments via accelerometry from September 16, 1998, to December 9, 2013, at ages 5, 8, 11, 13, 15, 17, and 19 years and completed a questionnaire every 6 months on sports participation and daily time spent in television viewing.

MAIN OUTCOMES AND MEASURES

Trajectories of MVPA (minutes per day), participation in organized sports (yes or no), and television viewing time (hours per day).

RESULTS

Based on the data from 537 participants (50.1% females; 94.6% white), we identified 4 MVPA trajectories: consistently inactive (14.9%), consistently active (18.1%), decreasing moderate physical activity (52.9%), and substantially decreasing high physical activity (14.1%). All participants in the consistently inactive trajectory also followed a trajectory of no participation in sports. The consistently active trajectory was associated with decreasing an already low television viewing trajectory (P < .001).

CONCLUSIONS AND RELEVANCE

This study provided a nuanced look at the known decrease in MVPA during childhood and adolescence. Sports participation could be a critical way to avoid the consistently inactive pattern. Most important, we identified a subset of participants who maintained a seemingly healthy level of MVPA from childhood to young adulthood. The developmental pathways of physical activity and television viewing behaviors could be related. Additional studies should examine the determinants and health consequences of these specific MVPA trajectories.

Physical activity and sedentary behaviour in European children: the IDEFICS study

OBJECTIVE

To estimate the prevalence of physical activity and sedentary behaviours in European children, and to evaluate the relationship between media availability in personal space and physical activity in relation to total screen time.

DESIGN

Data from the baseline IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cross-sectional survey. Information on hours of television/digital video disk/video viewing and computer/games-console use (weekday and weekend days), media device availability in personal space, sports club membership, hours of active organized play and commuting (to and from school) were assessed via a self-reported parental questionnaire. Total screen time was defined as the sum of daily media use and subsequently dichotomized into meeting or not meeting the guidelines of the American Academy of Pediatrics.

SETTING

Eight survey centres (Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary and Spain).

SUBJECTS

Children (n 15 330; 51% males) aged 2-10 years.

RESULTS

Percentage of children engaged in total screen time for >2 h/d was higher on weekend days (52% v. 20% on weekdays) and in the older group (71% in males; 57% in females), varying by country. Children with a television set in their bedroom were more likely not to meet the screen time recommendations (OR = 1·54; 95% CI 1·60, 1·74).

CONCLUSIONS

Approximately a third of the children failed to meet current screen time recommendations. Availability of a television set in personal space increased the risk of excess total screen time. This information could be used to identify potential targets for public health promotion actions of young population groups.

Longitudinal relations of television, electronic games, and digital versatile discs with changes in diet in adolescents

BACKGROUND

Youth spend more time with screens than any activity except sleeping. Screen time is a risk factor for obesity, possibly because of the influence of food and beverage advertising on diet.

OBJECTIVE

We sought to assess longitudinal relations of screen time [ie, television, electronic games, digital versatile discs (DVDs)/videos, and total screen time] with the 2-y changes in consumption of foods of low nutritional quality (FLNQ) that are commonly advertised on screens [ie, sugar-sweetened beverages, fast food, sweets, salty snacks, and the sum of these foods (total FLNQ)] and fruit and vegetables.

DESIGN

With the use of 2004, 2006, and 2008 waves of the Growing Up Today Study II, which consisted of a cohort of 6002 female and 4917 male adolescents aged 9-16 y in 2004, we assessed screen time (change and baseline) in relation to the 2-y dietary changes. Regression models included 4604 girls and 3668 boys with complete screen time and diet data on ≥2 consecutive questionnaires.

RESULTS

Each hour-per-day increase in television, electronic games, and DVDs/videos was associated with increased intake of total FLNQ (range: 0.10-0.28 servings/d; P < 0.05). Each hour-per-day increase in total screen time predicted increased intakes of sugar-sweetened beverages, fast food, sweets, and salty snacks (range: 0.02-0.06 servings/d; P < 0.001) and decreased intakes of fruit and vegetables (range: -0.05 to -0.02 servings/d; P < 0.05). Greater screen time at baseline (except electronic games in boys) was associated with subsequent increased intake of total FLNQ, and greater screen time at baseline (except DVDs/videos) was associated with decreased intake of fruit and vegetables (P < 0.05). Across sex and food groups and in sensitivity analyses, television was most consistently associated with dietary changes.

CONCLUSIONS

Increases in screen time were associated with increased consumption of foods and beverages of low nutritional quality and decreased consumption of fruit and vegetables. Our results caution against excessive use of screen media, especially television, in youth.

Estimation of leisure time physical activity and sedentary behaviour among school adolescents in Nepal

Background

Leisure-time physical activity is essential for healthy and physically active life; however, this domain of physical activity is less common in developing countries. Information on leisure time physical activity and sedentary behaviour among Nepalese population is not available. The study was carried out to assess leisure time physical activity and sedentary behaviour among high school adolescents and identify the associated factors in Nepal.

Methods

A cross-sectional descriptive study was carried out in Banke district, Nepal in 2013 among higher secondary school students using self-administered questionnaire based on International Physical Activity Questionnaire. A sample of 405 students, 178 females and 227 males, of the age–group 15 to 20 years from seven schools were included in the study. Multivariate logistic regression analysis was carried out to identify factors associated with participation in leisure time physical activity and sedentary behaviour.

Results

Engagement of female in leisure time physical activity was lower but mean time spent on sitting per day was higher. Students who walked to school and have playground/parks near home, younger females (OR = 3.09, 95% CI: 1.18-8.08), females living in nuclear families (OR: 2.16, 95% CI: 1.01-4.62) and males who cycled to school (OR: 8.09, 95% CI: 2.35-27.80) and have provision of extra-curricular activities (OR: 2.49, 95% CI: 1.04-5.97) were more likely to be engaged in leisure time physical activity. On the other hand, students who did not have playground in school and lived in rural areas were more likely to sit for more than 6 hours a day. Likewise, male students of private school (OR: 6.41, 95% CI: 2.89-14.21), who used vehicle to reach school (OR: 5.90, 95% CI: 1.26-27.75) and have no provision of extra-curricular activities (OR: 2.98, 95% CI: 1.09-8.07) had longer sitting time.

Conclusion

Difference in leisure time physical activity and sedentary behaviour was found among male and female school adolescents. Interventions are needed not only to promote leisure time physical activity but also to reduce sedentary behaviour among this group.

A cross-cultural comparison of health behaviors between Saudi and British adolescents living in urban areas: gender by country analyses

This study investigated the cross-cultural differences and similarity in health behaviors between Saudi and British adolescents. A school-based cross-sectional study was conducted at four cities in Saudi Arabia (Riyadh and Al-Khobar; N = 1,648) and Britain (Birmingham and Coventry; N = 1,158). The participants (14–18 year-olds) were randomly selected using a multistage stratified cluster sampling technique. Measurements included anthropometric, screen time, validated physical activity (PA) questionnaire and dietary habits. The overweight/obesity prevalence among Saudi adolescents (38.3%) was significantly (p < 0.001) higher than that found among British adolescents (24.1%). The British adolescents demonstrated higher total PA energy expenditure than Saudi adolescents (means ± SE = 3,804.8 ± 81.5 vs. 2,219.9 ± 65.5 METs-min/week). Inactivity prevalence was significantly (p < 0.001) higher among Saudi adolescents (64%) compared with that of British adolescents (25.5%). The proportions of adolescents exceeding 2 h of daily screen time were high (88.0% and 90.8% among Saudis and British, respectively). The majority of Saudi and British adolescents did not have daily intakes of breakfast, fruit, vegetables and milk. MANCOVA showed significant (p < 0.05) gender by country interactions in several lifestyle factors. There was a significant (p < 0.001) gender differences in the ratio of physical activity to sedentary behaviors. In conclusion, Saudi and British adolescents demonstrated some similarities and differences in their PA levels, sedentary behaviors and dietary habits. Unhealthy lifestyle behaviors among adolescents appear to be a cross-cultural phenomenon.

Conceptual understanding of screen media parenting: report of a working group

Screen media (television, computers, and videogames) use has been linked to multiple child outcomes, including obesity. Parents can be an important influence on children's screen use. There has been an increase in the number of instruments available to assess parenting in feeding and physical activity contexts, however few measures are available to assess parenting practices regarding children's screen media use. A working group of screen media and parenting researchers convened at the preconference workshop to the 2012 International Society for Behavioral Nutrition and Physical Activity (ISBNPA) annual meeting, "Parenting Measurement: Current Status and Consensus Reports," to identify and prioritize issues in assessing screen media parenting practices. The group identified that screen media use can pose different risks for children, depending on their age and developmental stage, across physiologic, psychosocial, and development outcomes. With that in mind, a conceptual framework of how parents may influence their child's screen-viewing behaviors was proposed to include the screen media content, context of viewing, and amount viewed. A research agenda was proposed to prioritize a validation of the framework and enhance the ability of researchers to best assess parenting influences across the three domains of content, context and amount of children's screen media use.

Association of dietary habits with levels of physical activity and screen time among adolescents living in Saudi Arabia

BACKGROUND

Understanding the inter-relationships between lifestyle factors in youth is important with respect to the development of effective promotional programmes for healthy eating and active living. The present study aimed to explore the associations of dietary habits (DH) with physical activity (PA) and screen time (ST) among Saudi adolescents aged between 15 and 19 years of age relative to gender.

METHODS

Data were obtained from the Arab Teens Lifestyle Study, a school-based multicentre lifestyle study conducted in 2009/2010 in three major cities in Saudi Arabia. A multistage stratified cluster random sampling technique was used. The number of participants with complete data for DH and PA was 2886 and the respective number for DH and ST was 2822. Assessment included weight, height, body mass index, total daily ST (television viewing, video/computer games and Internet use), PA and DH using self-reported questionnaires.

RESULTS

Females were significantly more sedentary and less active than males (P < 0.001). Two-way analysis of covariance, controlling for age, showed significant (P < 0.05) gender by PA and gender by ST interactions for several DH. Logistic regression analyses revealed significant associations of higher PA with a higher consumption of fruit, vegetables, milk, French fries/potato chips and energy drinks, whereas higher ST was significantly associated with a higher consumption of sugar-sweetened drinks, fast foods, cake/doughnuts and energy drinks.

CONCLUSIONS

Healthful dietary habits were associated mostly with PA, whereas sedentary behaviours, independent of PA, negatively impacted upon eating behaviours. The low PA levels and high sedentary levels of Saudi females represent a great concern. The results reported in the present study have important implications for both youth public health policies and intervention programmes.