Screen-based Sedentary Behavior Research Articles

Associations of Sedentary Behavior with Physical Fitness and Academic Performance among Chinese Students Aged 8-19 Years.

Background: Existing evidence regarding how time spent on various types of sedentary behavior (SB) in relation to physical fitness (PF) and academic performance (AP) in children and adolescents is limited. This cross-sectional study aimed to explore the associations of SB types with PF and AP among 8–19-year-old Chinese students. Methods: A total of 1164 students were recruited from five schools in Zhejiang province, China. Children’s SB was assessed by a valid questionnaire and AP was represented by scores on four courses. PF was measured by Chinese National Student PF Standard battery. The associations were assessed using linear mixed-effects models adjusted for age, school, grade, and class. Results: Students’ screen-based SB was observed to be negatively associated with PF in girls (p < 0.05). Screen-based SB was inversely associated with AP in both girls and boys (p < 0.001). The significant interaction between weekdays and weekends, and SB on AP was observed in girls (p < 0.001). On weekends, screen-based SB ≥ 6 h/day (<3 h/day as reference group) was significantly and negatively associated with AP (p < 0.01 for both sex). Conclusions: Longer screen-based SB, especially on weekends, was related to poorer AP in 8–19-year-old Chinese students. Our findings suggest that restrictions on any type of screen-based SB for leisure on weekends are beneficial to AP in Chinese students.

Children self-reports and Parent proxy reports of physical activity and sedentary behaviour

Abstract Background Aim of this study was to determine agreement between parent proxy reports and children self-reports of physical activities and sedentary behaviour. Methods The sample included 7-10 year-old children and their parents (n = 188) in a local community in Northern Serbia. Data were collected by questionnaires designed to assess context-specific measures of children’s physical activity (outside play, organized sports) and sedentary behavior (TV viewing, using computer, playing electronic games). Children and their parents completed questionnaires separately. Agreement between children’s and parent`s responses was calculated with Cohen’s kappa. Differences in parent`s and children`s responses in relation to gender, grade and BMI were analyzed using χ2 test. Values p &amp;lt; 0.05 were considered statistically significant. Results Level of agreement between parents’ and children’s reports ranged from poor for variable TV viewing before going to school (κ = 0.21; p = 0.04) to substantial for variable physical activity before going to school (κ = 0.74; p = 0.00). Girls were more likely than boys to agree with parents about time spent playing on the computer after school (χ2=11.23;p=0.01). Overweight and obese children tended to report more time in TV viewing than their parents (χ2=26.4;p=0.01). Conclusions There are differences in reports of physical activities and sedentary behaviour between 7 to 10 year-old children and their parents The lowest level of agreement found for variable TV viewing indicates low awareness and control of this screen-based sedentary behaviour. Key messages Differences in parents’ and children’s reports of children’s physical activities and sedentary behaviour are confirmed. It should be taken into consideration in studies which use self-reports or proxy reports for assessing children’s physical activities and sedentary behaviour.

A cross-sectional study investigating lifestyle and weight perception of undergraduate students in southern Italy

BackgroundThe aim of the study was to explore lifestyle of undergraduate students in southern Italy and to investigate their determinants.MethodsAn anonymous, web-based questionnaire investigating weight and its perception, smoking and alcohol use, achievement of recommended levels of physical activity and time spent daily in screen-based sedentary behaviors was administered to students attending two universities in southern Italy. Age, gender, city, type of degree course attended, occupational status and residential status were considered as possible demographic determinants.ResultsThe majority of the participants reported a normal weight (71.2%), were non-smokers (66.6%), occasional alcohol consumers (60.5%) and insufficiently active (62.6%), with a reported mean screen time exceeding 2 h per day. Gender, city, type of degree course and occupational status were found to be associated with lifestyle by regression analysis. Normal weight, overweight and obese students were generally properly aware of their weight condition; however, weight misperceptions were registered among normal and underweight undergraduates.ConclusionsThis study highlighted some critical issues regarding lifestyles of university students that suggest the need for health promotion interventions targeted mainly on physical activity.

Are Movement Behaviors and Fundamental Motor Skills Associated With Fitness and Fatness in Early Childhood? Findings From the 2012 NHANES National Youth Fitness Survey.

Using 2012 National Health and Nutrition Examination Survey (NHANES) National Youth Fitness Survey data, the authors conducted a cross-sectional secondary analysis to examine the associations of movement behaviors (ie,physical activity [PA] and screen-based sedentary behaviors) and fundamental motor skills (FMS) with fitness (ie,muscular fitness) and fatness (ie,body mass index and waist circumference) in 3- to 5-year-old children. The effect of ethnicity (Hispanic vs non-Hispanic) on these associations was also examined. A total of 352 children (173 girls; mean age = 4.02y) from the 2012 NHANES data set were included. Parents reported their child's PA and screen-based sedentary behaviors. FMS (ie,locomotor and object control) were assessed with the Test of Gross Motor Development, 2nd edition. Other variables used were body mass index, waist circumference, and plank. Hispanic children demonstrated lower levels of PA than non-Hispanic children (P < .05). Children's FMS emerged as significant predictors of muscular fitness and waist circumference, but not for body mass index in the Hispanic group. In the non-Hispanic group, FMS (ie,object control skills) and PA accounted for significant variances of muscular fitness and waist circumference, respectively. The associations of movement behaviors and FMS with fitness and fatness are different between Hispanic and non-Hispanic young children. Changes in policy or early childhood curriculum may be tailed to promote FMS for an impact on fitness and fatness in both Hispanic and non-Hispanic children.

Efeito da substituição do tempo de tela e atividades físicas no lazer na percepção positiva de saúde de universitários

O objetivo deste estudo foi estimar o impacto da substituição do tempo de prática de atividades físicas no lazer e comportamentos sedentários sobre a autoavaliação positiva da saúde em universitários de uma instituição de ensino superior do estado da Bahia. Foram realizados dois inquéritos repetidos com universitários de uma mesma instituição nos anos de 2012 e 2014. A autoavaliação positiva de saúde foi o desfecho deste estudo. O tempo por dia despendido em 17 modalidades e o tempo no total de atividades físicas no lazer, mais quatro comportamentos sedentários de tela e tempo de tela no total foram padronizados por uma constante de 30 minutos. O modelo de substituição isotemporal foi empregado por meio da estimativa do Odds Ratio (OR), via regressão logística binaria. O nível de significância foi de 5%. Houve a participação de 1.085 e 1.041 universitários nos anos de 2012 e 2014, respectivamente. Observou-se maiores chances de percepção positiva da saúde ao realocar o tempo de uso de computador em pesquisas para a prática de futebol, lutas, corrida em esteira e musculação. De modo geral, maiores chances de autoavaliação positiva da saúde foram mostrados ao realocar 30 minutos por dia do tempo de tela no total para o tempo de prática de atividades físicas no lazer no total (OR = 1,14; IC95%: 1,10–1,18). Conclui-se que substituir pelo menos 30 minutos por dia de uso de computador em pesquisas para a prática de atividades físicas no lazer, maximiza a autoavaliação positiva do nível de saúde em universitários.

Social correlates of sedentary behavior in young people: The UP&DOWN study

PurposeThe aim of the present study was to analyze the associations of youths’ sedentary behavior (SB) with parents’ and siblings’ SB and physical activity (PA), as well as the associations of youths’ coparticipation with parents, siblings, and friends in PA and SB with youths’ SB. MethodsThe sample consisted of 1543 youths (12.02 ± 2.51 years; 788 boys) enrolled in the baseline cohort of the UP&DOWN study. SB was assessed by accelerometry and questionnaire. Participants reported the time spent by their parents and siblings watching television, playing videogames, surfing the Internet, sitting/resting, and doing PA. Further, participants reported coparticipation with parents, siblings, and friends in these activities. Linear mixed models, including school and city as random effects, were performed. ResultsParents’ television time was positively associated with youths’ screen-based SB. Coparticipation with friends in playing videogames (in boys) and in surfing the Internet (in girls) showed a positive association with screen-based SB and a negative association with educational-based SB. Moreover, coparticipation with siblings and friends in PA was inversely associated with accelerometer-based SB in boys and girls. ConclusionOur results emphasize the important role of social modeling in the development of sedentary lifestyles in youths. Interventions aimed at reducing health risk behaviors in youths could be more effective if they are oriented from a social perspective that involves their families and networks of their closest friends.

Screen-based sedentary behaviors and internalizing symptoms across time among U.S. Hispanic adolescents

IntroductionThe pervasive use of technology has raised concerns about its association with adolescent mental health, including internalizing symptoms. Existing studies have not always had consistent findings. Longitudinal research with diverse subgroups is needed. MethodsThis study examines the relationship between screen-based sedentary (SBS) behaviors and internalizing symptoms among 370 Hispanic adolescents living in Miami, Florida- United States, who were followed for 2 ½ years and assessed at baseline, 6, 18 and 30 months post-baseline between the years 2010 and 2014. Approximately 48% were girls, and 44% were foreign-born, most of these youth being from Cuba. Mean age at baseline was 13.4 years, while at the last time-point it was 15.9 years. ResultsFindings show that girls had higher internalizing symptoms and different patterns of screen use compared to boys, including higher phone, email, and text use. SBS behaviors and internalizing symptoms cooccurred at each time-point, and their trajectories were significantly related (r = 0.45, p < .001). Cross-lagged panel analyses found that SBS behaviors were not associated with subsequent internalizing symptoms. Among girls, however, internalizing symptoms were associated with subsequent SBS behaviors during later adolescence, with internalizing symptoms at the 18-month assessment (almost 15 years old) associated with subsequent SBS behaviors at the 30-month assessment (almost 16 years old; β = 0.20, p < .01). ConclusionsContinued research and monitoring of internalizing symptoms and screen use among adolescents is important, especially among girls. This includes assessments that capture quantity, context, and content of screen time.

Reciprocal associations between screen time and emotional disorder symptoms during adolescence.

Screen-based sedentary behaviors and emotional disorders are associated with one another in youth. Yet, the direction of the association is unclear, as is whether specific types of screen-based sedentary behaviors and emotional disorder symptoms are more closely linked. This study estimated the bi-directional associations between two types of screen-based sedentary behaviors and four types of self-reported emotional disorder symptoms, and tested whether physical activity buffered these associations in a Los Angeles high school student cohort (N = 2525, baseline Mage = 14.6 years). Participants completed baseline (9th Grade, 2013) and 12-month follow-up (10th grade, 2014) surveys reporting on: television viewing and computer/videogame use (≥4 h/day; yes/no), physical activity (≥60 min/day for ≥5 days/week), and Major Depressive Disorder (MDD), Generalized Anxiety Disorder (GAD), Panic Disorder (PD), and Social Phobia (SP) symptoms (meet/exceed [sub]clinical symptom threshold; yes/no). After adjusting for baseline screen-based sedentary behavior and covariates, students with (sub)clinical baseline MDD and GAD were at increased odds of high computer/videogame use one year later (OR = 1.36[95%CI, 1.07–1.73]; OR = 1.36[95%CI,1.09–1.71], respectively). Baseline SP was marginally related to increased computer/videogame use at follow-up (OR = 1.33[95%CI,1.04–1.69]). Greater baseline computer/videogame use was associated with increased odds of (sub)clinical GAD (OR = 1.54[95%CI,1.23–1.94]) and (sub)clinical SP (OR = 1.64[95%CI 1.27–2.12]) at follow-up; these associations were suppressed among baseline physically active students. Television viewing was unrelated to emotional disorder symptoms and PD was not associated with screen-based sedentary behaviors. Thus, only reciprocal associations between computer/videogame use, SP, and GAD during a one-year period of adolescence were observed. Interventions reducing computer/videogame use and increasing physical activity may improve adolescent emotional health.

Agreement between parents’ proxy reports and children’s self-reports of physical activity and sedentary behavior in children aged 7 – 10 years in Vojvodina

Introduction. The aim of this study was to determine the agreement between parents? and children?s reports of children?s physical activity and screen-based sedentary activities. Material and Methods. The sample included 7 - 10 year-old children (n = 94) and their parents (n = 94) in a local community in Vojvodina. Parents and children separately completed question?naires about the types of physical and sedentary activities and the time children spent in different activities during one day. The agreement between children?s and parents? responses was calculated using Cohen?s kappa. The differences in parents? and children?s responses in relation to gender and grade the students attended were analyzed using ?2 test. P-values less than 0.05 were considered statistically significant. Results. The highest level of agreement (? = 0.74; p = 0.00) was found for the questions concerning physical activity in the morning before going to school. The lowest level of agreement was found for watching TV in the morning before going to school (? = 0.21; p = 0.04). Children reported spending more time in screen-based sedentary activities than their parents. Conclusion. This research showed that there are differences in reports of children?s physical activities and screen time obtained from children aged 7 to 10 years and their parents. The lowest level of agreement was found for watching television, indicating low level of awareness and control of this screen-based sedentary behavior.

Environmental correlates of total and domain-specific sedentary behaviour in young people. The UP&DOWN study

This study investigated the associations between the characteristics of the nearby physical environment with the total and domain-specific leisure-time sedentary behaviour (SB) in young people. The study included 1578 youth (9–18 years) from the UP&DOWN study. Total leisure-time SB was objectively-assessed by accelerometers. Participants self-reported the time spent during leisure-time in different domains of SB (i.e. screen-based, educational-based, social-based, and other-based SB). Information regarding the basic characteristics of the house, the perceived neighbourhood environment, the amount of physical activity facilities, equipment and materials attainable at home, and the media equipment available at home and in the own bedroom was collected. Linear mixed models were performed, including school and city as random effects. The availability of yard was related to lower total SB and time spent surfing the Internet in boys, but not in girls. More favourable perceived neighbourhood environment was associated with lower total SB and time spent playing video games in girls, but not in boys. The amount of physical activity materials at home was negatively associated with screen-based SB, while the availability of a computer in the own bedroom was positively related to the time spent surfing the Internet in boys and girls. The number of televisions at home and having a computer in the own bedroom was associated with lower time in educational-based SB in boys and girls, respectively. Increasing the number of PA materials at home and decreasing the number of TVs at home and the availability of a computer in the bedroom could improve SB profiles of youth.

The relationship between sedentary behaviour and physical literacy in Canadian children: a cross-sectional analysis from the RBC-CAPL Learn to Play study

BackgroundPhysical literacy is the foundation of a physically active lifestyle. Sedentary behaviour displays deleterious associations with important health indicators in children. However, the association between sedentary behaviour and physical literacy is unknown. The purpose of this study was to identify the aspects of physical literacy that are associated with key modes of sedentary behaviour among Canadian children participating in the RBC-CAPL Learn to Play study.MethodsA total of 8,307 children aged 8.0-12.9 years were included in the present analysis. Physical literacy was assessed using the Canadian Assessment of Physical Literacy, which measures four domains (Physical Competence, Daily Behaviour, Motivation and Confidence, Knowledge and Understanding). Screen-based sedentary behaviours (TV viewing, computer and video game use), non-screen sedentary behaviours (reading, doing homework, sitting and talking to friends, drawing, etc.) and total sedentary behaviour were assessed via self-report questionnaire. Linear regression models were used to determine significant (p<0.05) correlates of each mode of sedentary behaviour.ResultsIn comparison to girls, boys reported more screen time (2.7±2.0 vs 2.2±1.8 hours/day, Cohen’s d=0.29), and total sedentary behaviour (4.3±2.6 vs 3.9±2.4 hours/day, Cohen’s d=0.19), but lower non-screen-based sedentary behaviour (1.6±1.3 vs 1.7±1.3 hours/day, Cohen’s d=0.08) (all p< 0.05). Physical Competence (standardized β’s: -0.100 to -0.036, all p<0.05) and Motivation and Confidence (standardized β’s: -0.274 to -0.083, all p<0.05) were negatively associated with all modes of sedentary behaviour in fully adjusted models. Knowledge and Understanding was negatively associated with screen-based modes of sedentary behaviour (standardized β’s: -0.039 to -0.032, all p<0.05), and positively associated with non-screen sedentary behaviour (standardized β: 0.098, p<0.05). Progressive Aerobic Cardiovascular Endurance Run score and log-transformed plank score were negatively associated with all screen-based modes of sedentary behaviour, while the Canadian Agility and Movement Skill Assessment score was negatively associated with all modes of sedentary behaviour other than TV viewing (all p<0.05).ConclusionsThese results highlight differences in the ways that screen and non-screen sedentary behaviours relate to physical literacy. Public health interventions should continue to target screen-based sedentary behaviours, given their potentially harmful associations with important aspects of physical literacy.

Physical activity, sedentary behaviour and risk of oesophago-gastric cancer: A prospective cohort study within UK Biobank.

Few observational studies have assessed the role of physical activity in oesophago-gastric cancer risk. This prospective cohort study aimed to assess the association between physical activity and risk of oesophageal or gastric cancer. A cohort of 359,033 adults aged 40-69 years were identified from the UK Biobank, which recruited participants between 2006 and 2010. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between self-reported levels of physical activity and screen-based sedentary behaviour and risk of oesophageal and gastric cancer were calculated using Cox proportional hazards models. During eight years of follow-up (mean = 5.5), 294 oesophageal cancer and 217 gastric cancer cases were identified. Physical activity and screen-based sedentary behaviour levels were not associated with overall oesophago-gastric cancer risk. However, when compared with low levels, high physical activity levels were associated with a significantly reduced risk of gastric non-cardia cancer (HR 0.58, 95% CI 0.37-0.95). Moderate physical activity levels were associated with a 38% reduced risk of oesophageal adenocarcinoma (HR 0.62, 95% CI 0.43-0.89), although no dose-response association was apparent. Moderate, rather than high, physical activity levels were associated with the strongest reductions in oesophageal adenocarcinoma risk in this large UK prospective cohort.

Leisure-time physical activity at moderate and high intensity is associated with parameters of body composition, muscle strength and sarcopenia in aged adults with obesity and metabolic syndrome from the PREDIMED-Plus study

We aimed to examine the associations of leisure-time physical activity (PA) and sedentary behavior (SB) with the prevalence of sarcopenia, body composition and muscle strength among older adults having overweight/obesity and metabolic syndrome, from the PREDIMED-Plus trial. Cross-sectional baseline analysis including 1539 men and women (65±5y). Sarcopenia was defined as low muscle mass (according to FNIH cut-offs) plus low muscle strength (lowest sex-specific tertile for 30-s chair-stand test). We applied multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design) for the associations of self-reported leisure-time PA and SB with sarcopenia; and multivariable-linear regression for the associations with dual-energy X-ray absorptiometry (DXA)-derived bone mass, fat mass, lean mass and lower-limb muscle strength. Inverse associations were observed between sarcopenia and each hourly increment in total [prevalence ratio 0.81 (95% confidence interval, 0.70, 0.93)], moderate [0.80 (0.66, 0.97)], vigorous [0.51 (0.32, 0.84)], and moderate-vigorous PA (MVPA) [0.74 (0.62, 0.89)]. Incrementing 1-h/day total-PA and MVPA was inversely associated with body-mass-index, waist circumference (WC), fat mass, and positively associated with bone mass and lower-limb muscle strength (all P<.05). One h/day increase in total SB, screen-based SB and TV-viewing was positively associated with body-mass-index, WC and fat mass. Light-PA was not significantly associated with any outcome. Total-PA and PA at moderate and high intensities may protect against the prevalence of sarcopenia, have a beneficial role on body composition and prevent loss of muscle strength. SB, particularly TV-viewing, may have detrimental effects on body composition in older adults at high cardiovascular risk.

Correlates of screen time among 8\u201319-year-old students in China

BackgroundPrevious studies have shown that prolonged time spent on screen-based sedentary behavior was significantly associated with lower health status in children, independent of physical activity levels. The study aimed to explore the individual and environmental correlates of screen time (ST) among 8–19-year-old students in China.MethodsThe study surveyed ST using a self-administered questionnaire in Chinese students aged 8–19 years; 1063 participants were included in the final analysis. Individual and environmental correlates of ST were assessed using a mixed-effects model (for continuous outcome variables) and multiple logistic regression model (for binary outcome variables).ResultsProlonged ST was observed in 14.7% of boys and 8.9% of girls. Of the ST, weekend and mobile phone/tablet use represented 80% and 40%, respectively. A positive relationship was observed between media accessibility and ST in both boys and girls (p < 0.05), whereas the presence of parents/others while using screens was a negative factor for longer ST (p < 0.05). Among the assessed correlates, access to a television (TV) in students’ bedrooms was associated with prolonged total and weekend ST (p < 0.05 and p < 0.001, respectively). However, spending time on a mobile phone/tablet or a computer rather than viewing a TV, along with increased media accessibility, increased ST.ConclusionsThese results indicate that greater media accessibility was positively associated and the presence of parents/others was negatively associated with prolonged ST in both Chinese boys and girls. Development of new and effective strategies against prolonged ST are required, especially for small screen device-based ST on weekends.

Health-related correlates of psychological well-being among girls and boys 6-8 years of age: The Physical Activity and Nutrition in Children study.

Due to limited knowledge on the differences in the correlates of psychological well-being (PSWB) between girls and boys, we compared the correlates of PSWB between primary school girls and boys. A population sample of 412 children participated in the Physical Activity and Nutrition in Children study. Parents completed a questionnaire that included 19 questions on the components of PSWB, and a PSWB score was computed. We assessed correlates of PSWB, including physical activity, sedentary behaviour, cardiorespiratory fitness, diet quality, body fat content, sleep duration, sleep disordered breathing, prevalent diseases and parental characteristics. We used logistic regression to analyse the risk of being in the lowest third of the PSWB scores. Low parental education was associated with increased risk (odds ratio (OR) 2.34, P = 0.039) and high cardiorespiratory fitness with decreased risk (OR 0.26, P = 0.006) of poor PSWB in girls. At least 2 h of screen-based sedentary behaviour per day (OR 1.93, P = 0.037), daily parental smoking (OR 2.10, P = 0.034) and sleep disordered breathing (OR 4.24, P = 0.003) were related to increased risk of poor PSWB in boys. There are large differences in the correlates of PSWB between girls and boys. Most of these correlates are modifiable and related to the health behaviour of children and their parents.

Screen-based sedentary behaviors, mental health, and social relationships among adolescents

Abstract Aim: To analyze the association between screen-based sedentary behaviors, mental health, and social relationships in Brazilian adolescents. Methods: A representative sample of the adolescents from Londrina/PR was selected (n = 1,158; 10 to 17 y). Weekday and weekend screen time (TV-viewing and computer/video-game), mental health indicators (self-rated health, stress, feelings of sadness, and satisfaction with own body), and perceived social relationships (friends, family, and teachers) were collected through questionnaires. Somatic maturation, body mass index, and physical activity were assessed as covariates. Results: Adolescents who reported higher TV-viewing presented higher odds (p < 0.05) for poor self-rated health (boys), higher stress (both sexes), and dissatisfaction with own body (boys), friendships (girls), and teachers (girls). In contrast, higher computer/video-game use was associated with lower odds (p < 0.05) for poor self-rated health (girls), higher stress (boys), feelings of sadness (both sexes), and dissatisfaction with friends (both sexes) and family (both sexes). Conclusion: While higher TV-viewing is associated with negative outcomes, higher computer/video-game users demonstrate better mental health and lower satisfaction with their social relationships.

Meeting new Canadian 24-Hour Movement Guidelines for the Early Years and associations with adiposity among toddlers living in Edmonton, Canada

BackgroundCanada has recently released guidelines that include toddler-specific recommendations for physical activity, screen-based sedentary behaviour, and sleep. This study examined the proportions of toddlers meeting the new Canadian 24-Hour Movement Guidelines for the Early Years (0–4 years) and associations with body mass index (BMI) z-scores in a sample from Edmonton, Canada.MethodsParticipants included 151 toddlers (aged 19.0 ± 1.9 months) for whom there was complete objectively measured physical activity data from the Parents’ Role in Establishing healthy Physical activity and Sedentary behaviour habits (PREPS) project. Toddlers’ physical activity was measured using ActiGraph wGT3X-BT monitors. Toddlers’ screen time and sleep were measured using the PREPS questionnaire. Toddlers’ height and weight were objectively measured by public health nurses and BMI z-scores were calculated using World Health Organization growth standards. Meeting the overall 24-Hour Movement Guidelines was defined as: ≥180 min/day of total physical activity, including ≥1 min/day of moderate- to vigorous-intensity physical activity; no screen time per day (for those aged 12–23 months) or ≤1 h/day of screen time per day (ages 24–35 months); and 11–14 h of sleep per 24-h period. Frequency analyses and linear regression models were conducted.ResultsOnly 11.9% of toddlers met the overall 24-Hour Movement Guidelines, but this finding was largely driven by screen time. The majority of toddlers met the individual physical activity (99.3%) and sleep (82.1%) recommendations, while only 15.2% of toddlers met the screen time recommendation. No associations were observed between meeting specific and general combinations of recommendations within the guidelines and BMI z-scores.ConclusionsMost toddlers in this sample were meeting physical activity and sleep recommendations but were engaging in more screen time than recommended. Consequently, only a small proportion of toddlers met the overall guidelines. Based on the findings of this study, identifying modifiable correlates of screen time to inform appropriate strategies to reduce screen time appears key for increasing the proportion of toddlers meeting the 24-Hour Movement Guidelines for the Early Years. Future research should examine the associations between meeting the new guidelines and other health indicators. Furthermore, future high-quality studies examining dose-response relationships between movement behaviours and health indicators are needed to inform guideline updates.

Perceived neighborhood safety related to physical activity but not recreational screen-based sedentary behavior in adolescents

BackgroundA growing proportion of adolescents have poor cardiovascular health behaviors, including low levels of physical activity and high levels of sedentary behavior, thus increasing the likelihood of poor heart health in later years. This study tested the hypothesis that low perceived neighborhood safety would be associated with low levels of physical activity and high levels of recreational sedentary behavior in high-school students.MethodsUsing cross-sectional, weighted data from the 2015 Pennsylvania (USA) State and Philadelphia city Youth Risk Behavior Survey, multivariable logistic regression modeling was used to examine the association between perceived neighborhood safety, and physical activity levels and recreational screen-based sedentary behavior time respectively, while controlling for potential confounders.ResultsAfter adjustment for other significant correlates of physical activity, students with low perceived neighborhood safety had a 21% reduced odds of being physically active on 5 or more days of the last week as compared to those who felt safe (p = 0.044). Perceived safety was not related to sedentary behavior; but sports team participation emerged as a strong correlate of low screen-based sedentary behavior (OR = 0.73, p = .002).ConclusionThese data add to a growing body of work demonstrating the importance of perceived safety with physical activity levels in youth. Sports team participation may be a viable target to reduce screen-based sedentary time.

The Ubiquity of the Screen: An Overview of the Risks and Benefits of Screen Time in Our Modern World

ABSTRACT Sedentary behavior, and specifically screen-based sedentary behavior, has been a focus for health researchers, engineers, telecommunications companies, gamers, and the media for many years. In recent years, research in this area has proliferated at an exponential rate. On one side, arguments have been made that screen time is harmful to the healthy growth and development of children and youth. On the other side, modern technology has far surpassed any prediction of success and become a fixture of daily living, making life easier and providing opportunities never thought possible. Regardless, screens have become omnipresent in our society, and it is important to understand the risks and the benefits associated with their use. Excessive time spent in various sedentary behaviors can coexists in a lifestyle that includes sufficient levels of moderate- to vigorous-intensity physical activity, but research has shown that for optimal health benefits, individuals should be both physically active and limit their sedentary behaviors (especially screen time). This narrative review provides a brief history of research on sedentary behavior in the context of screen time, the evolution of screens and screen time, highlights the risks and benefits of screen-based sedentary behavior, and provides experimental evidence for reductions in habitual screen time.

Television Watching and Telomere Length Among Adults in Southwest China.

To explore the independent associations of sedentary behavior and physical activity with telomere length among Chinese adults. Data on total time of sedentary behavior, screen-based sedentary behavior (including television watching and computer or phone use), moderate to vigorous physical activity, and dietary intake of 518 adults in Chengdu, Guizhou, and Xiamen in China (54.25% women) aged 20 to 70 years were obtained between 2013 and 2015 through questionnaires. Height, weight, and waist circumference were measured to calculate body mass index and percentage of body fat. Telomere length was measured through Southern blot technique. Television watching was inversely related to adjusted telomere length (-71.75 base pair; SE = 34.40; P = .04). Furthermore, a similar trend between telomere length and television watching was found in the group aged 20 to 40 years after adjusting for all covariates. Adults aged 20 to 40 years in the highest tertile of daily time spent on watching television had 4.0% shorter telomere length than adults in the lowest tertile (P = .03). Although the association is modest, television watching is inversely related to telomere length among Chinese adults, warranting further investigation in large prospective studies.