Changing from primary to secondary school highlights opportunities for school environment interventions aiming to increase physical activity and reduce sedentary behaviour: a longitudinal cohort study.

BACKGROUND: There is little empirical evidence of the impact of transition from primary to secondary school on obesity-related risk behaviour. The purpose of this study was to examine the effect of a change of school system on physical activity (PA) and sedentary behaviour in pre-early adolescents. METHODS: Fifteen schools in Victoria, Australia were recruited at random from the bottom two strata of a five level socio-economic scale. In nine schools, students in year 6 primary school transitioned to a different school for year 7 secondary school, while in six schools (combined primary-secondary), students remained in the same school environment from year 6 to year 7. Time 1 (T1) measures were collected from students (N=245) in year 6 (age 11-13). Time 2 (T2) data were collected from 243 (99%) of the original student cohort when in year 7. PA and sedentary behaviour data were collected objectively (via ActiGraph accelerometer) and subjectively (via child self-report recall questionnaire). School environment data were collected via school staff survey. Change of behaviour analyses were conducted longitudinally i) for all students and ii) by change/no change of school. Mixed model regression analysis tested for behavioural interaction effects of changing/not changing school. RESULTS: Sixty-three percent (N=152) changed schools from T1 to T2. Across all students we observed declines in average daily moderate to vigorous physical activity (MVPA) (-4 min) and light PA (-23 min), and increases in average daily sedentary behaviour (16 min), weekday leisure screen time (17 min) and weekday homework screen time (25 min), all P<0.05. Compared to students who remained in the same school environment, students who changed school reported a greater reduction in PA intensity at recess and lunch, less likelihood to cycle to/from school, greater increase in weekday (41 mins) and weekend (45 mins) leisure screen time (P<0.05) and greater encouragement to participate in sport. School staff surveys identified that sport participation encouragement was greater in primary and combined primary-secondary than secondary schools (P<0.05). CONCLUSION: Transitioning from primary to secondary school negatively impacts on children's PA and sedentary behaviour, and has further compounding effects on behaviour type by changing school environments.

The association between sedentary behaviour and risk of anxiety: a systematic review

BACKGROUND: Previous research has linked sedentary behaviour (SB) to adverse physical health outcomes in adults and youth. Although evidence for the relationship between SB and mental health outcomes (e.g., depression) is emerging, little is known regarding risk of anxiety. METHODS: A systematic search for original research investigating the association between SB and risk of anxiety was performed using numerous electronic databases. A total of nine observational studies (seven cross-sectional and two longitudinal) were identified. Methodological quality of studies was assessed and a best-evidence synthesis was conducted. RESULTS: One cross-sectional study demonstrated a strong methodological quality, five cross-sectional studies demonstrated a moderate methodological quality and three studies (two cross-sectional one longitudinal) received a weak methodological quality rating. Overall, there was moderate evidence for a positive relationship between total SB and anxiety risk as well as for a positive relationship between sitting time and anxiety risk. There was inconsistent evidence for the relationship between screen time, television viewing time, computer use, and anxiety risk. CONCLUSION: Limited evidence is available on the association between SB and risk of anxiety. However, our findings suggest a positive association (i.e. anxiety risk increases as SB time increases) may exist (particularly between sitting time and risk of anxiety). Further high-quality longitudinal/interventional research is needed to confirm findings and determine the direction of these relationships.

Patterns of sedentary behaviour and cardiovascular health in children

 Children engaged in high levels of sedentary time, particularly during class and leisure time. Different types of screen behaviours and patterns of sitting time were adversely associated with cardiovascular health. Not all screen behaviours may be equal and the way sitting time is accumulated may be important to cardiovascular health.

Contribution of the after-school period to children’s daily participation in physical activity and sedentary behaviours

Objectives: Children’s after-school physical activity (PA) and sedentary behaviours (SB) are not well understood, despite the potential this period holds for intervention. This study aimed to describe children’s after-school physical activity and sedentary behaviours; establish the contribution this makes to daily participation and to achieving physical activity and sedentary behaviours guidelines; and to determine the association between after-school moderate- to vigorous-intensity physical activity (MVPA), screen-based sedentary behaviours and achieving the physical activity and sedentary behaviour guidelines.Methods: Children (n=406, mean age 8.1 years, 58% girls) wore an ActiGraph GT3X accelerometer. The percentage of time and minutes spent sedentary (SED), in light- physical activity (LPA) and MVPA between the end-of-school and 6pm (weekdays) was calculated. Parents (n=318, 40 years, 89% female) proxy-reported their child’s after-school participation in screen-based sedentary behaviours. The contribution that after-school SED, LPA, MVPA, and screen-based sedentary behaviours made to daily levels, and that after-school MVPA and screen-based sedentary behaviours made to achieving the physical activity/sedentary behaviour guidelines was calculated. Regression analysis determined the association between after-school MVPA and screen-based sedentary behaviours and achieving the physical activity/sedentary behaviours guidelines.Results: Children spent 54% of the after-school period SED and this accounted for 21% of children’s daily SED levels. Boys spent a greater percentage of time in MVPA than girls (14.9% vs. 13.6%; p<0.05) but this made a smaller contribution to their daily levels (27.6% vs 29.8%; p<0.05). After school, boys and girls respectively performed 18.8 minutes and 16.7 minutes of MVPA which is 31.4% and 27.8% of the MVPA (p<0.05) required to achieve the physical activity guidelines. Children spent 96 minutes in screen-based sedentary behaviours, contributing to 84% of their daily screen-based sedentary behaviours and 80% of the sedentary behaviour guidelines. After-school MVPA was positively associated with achieving the physical activity guidelines (OR: 1.31, 95%CI 1.18, 1.44, p<0.05) and after-school screen-based sedentary behaviours was negatively associated with achieving the sedentary behaviours guidelines (OR: 0.97, 95%CI: 0.96, 0.97, p<0.05).Conclusions: The after-school period plays a critical role in the accumulation of children’s physical activity and sedentary behaviours. Small changes to after school behaviours can have large impacts on children’s daily behaviours levels and likelihood of meeting the recommended levels of physical activity and sedentary behaviour. Therefore interventions should target reducing after-school sedentary behaviours and increasing physical activity.

Physical activity, screen-based behaviours and obesity among Fijian adolescents

 This PhD investigated obesity and mental health issues. Physical activity, screen-based behaviour (including e-gaming) measures don’t seem to be closely linked to BMI-z or psychosocial outcomes in Fijian adolescents. Expectations of the BMI-z impact of PA programs should be low and control on violent e-gaming through licensing agreements is suggested.

Is the relationship between sedentary behaviour and cardiometabolic health in adolescents independent of dietary intake? A systematic review

Screen time, but not overall sedentary behaviour, is consistently related to cardiometabolic health in adolescents. Because of the associations screen time has with dietary intake, diet may be an important factor in the screen time and health relationship; however, evidence has not previously been synthesized. Thus, the aim of this systematic review was to explore whether the associations between various sedentary behaviours and cardiometabolic risk markers are independent of dietary intake in adolescents. Online databases and personal libraries were searched for peer-reviewed original research articles published in English before March 2014. Included studies assessed associations between sedentary behaviour and cardiometabolic markers in 12- to 18-year-olds and adjusted for dietary intake. Twenty-five studies met the inclusion criteria. From the 21 studies examining sedentary behaviour and adiposity, the majority found significant positive associations between television viewing, screen time and self-reported overall sedentary behaviour with markers of adiposity, independent of dietary intake. No significant associations between screen time with blood pressure and cholesterol were reported. Sedentary behaviour appears to be associated with adiposity in adolescents, irrespective of dietary intake. However, the variability of dietary variables between studies suggests further work is needed to understand the role of dietary intake when examining these associations in youth.

Objectively measured sedentary behaviour and health and development in children and adolescents: systematic review and meta-analysis

Sedentary behaviour has emerged as a unique determinant of health in adults. Studies in children and adolescents have been less consistent. We reviewed the evidence to determine if the total volume and patterns (i.e. breaks and bouts) of objectively measured sedentary behaviour were associated with adverse health outcomes in young people, independent of moderate-intensity to vigorous-intensity physical activity. Four electronic databases (EMBASE MEDLINE, Ovid EMBASE, PubMed and Scopus) were searched (up to 12 November 2015) to retrieve studies among 2- to 18-year-olds, which used cross-sectional, longitudinal or experimental designs, and examined associations with health outcomes (adiposity, cardio-metabolic, fitness, respiratory, bone/musculoskeletal, psychosocial, cognition/academic achievement, gross motor development and other outcomes). Based on 88 eligible observational studies, level of evidence grading and quantitative meta-analyses indicated that there is limited available evidence that the total volume or patterns of sedentary behaviour are associated with health in children and adolescents when accounting for moderate-intensity to vigorous-intensity physical activity or focusing on studies with low risk of bias. Quality evidence from studies with robust designs and methods, objective measures of sitting, examining associations for various health outcomes, is needed to better understand if the overall volume or patterns of sedentary behaviour are independent determinants of health in children and adolescents.

Validity and reliability of measures of television viewing time and other non-occupational sedentary behaviour of adults : a review

Time spent in non-occupational sedentary behaviours (particularly television viewing time) is associated with excess adiposity and an increased risk of metabolic disorders among adults; however, there are no reviews of the validity and reliability of assessing these behaviours. This paper aims to document measures used to assess adults' time spent in leisure-time sedentary behaviours and to review the evidence on their reliability and validity. Medline, CINAHL and Psych INFO databases and reference lists from published papers were searched to identify studies in which leisure-time sedentary behaviours had been measured in adults. Sixty papers reporting measurement of at least one type of leisure-time sedentary behaviour were identified. Television viewing time was the most commonly measured sedentary behaviour. The main method of data collection was by questionnaire. Nine studies examined reliability and three examined validity for the questionnaire method of data collection. Test–retest reliabilities were predominantly moderate to high, but the validity studies reported large differences in correlations of self-completion questionnaire data with the various referent measures used. To strengthen future epidemiological and health behaviour studies, the development of reliable and valid self-report instruments that cover the full range of leisure-time sedentary behaviour is a priority.

Too little exercise and too much sitting : inactivity physiology and the need for new recommendations on sedentary behaviour

Moderate-to vigorous-intensity physical activity has an established preventive role in cardiovascular disease, type 2 diabetes, obesity, and some cancers. However, recent epidemiologic evidence suggests that sitting time has deleterious cardiovascular and metabolic effects that are independent of whether adults meet physical activity guidelines. Evidence from “inactivity physiology” laboratory studies has identified unique mechanisms that are distinct from the biologic bases of exercising. Opportunities for sedentary behaviors are ubiquitous and are likely to increase with further innovations in technologies. We present a compelling selection of emerging evidence on the deleterious effects of sedentary behavior, as it is underpinned by the unique physiology of inactivity. It is time to consider excessive sitting a serious health hazard, with the potential for ultimately giving consideration to the inclusion of too much sitting (or too few breaks from sitting) in physical activity and health guidelines.

Internet-based cognitive behaviour therapy for erectile dysfunction

This thesis involved the development and evaluation of "Rekindle", an internet-based cognitive behaviour therapy (CBT) for erectile dysfunction (ED). For highly motivated couples, "Rekindle" was more effective than no treatment for improving sexual function and relationships. Most men who completed "Rekindle" had maintained treatment gains at 3-month follow-up. The professional portfolio presented 4 case studies which demonstrate that barriers to recovery from early psychosis are often complex and challenging issues, and that effective strategies need to be implemented to overcome these issues during treatment. When insufficient intervention is provided to address these barriers, the likelihood of successful outcome following early psychosis is significantly reduced.

Physical activity, sedentary behaviour and depression among socio-economically disadvantaged women

Promoting physical activity, particularly for leisure and transport, could be an important aspect in preventing depression amongst women living in disadvantaged neighbourhoods. Furthermore, including some aspect of social physical activity and reducing time spent in sedentary behaviours may further reduce risk of depression.

Lack of relationship between sedentary behaviour and vascular function in children

Some evidence suggests that sedentary behaviour is independently associated with cardiovascular (CV) risk. Endothelial dysfunction is the earliest detectable manifestation of CVD and a strong independent predictor of CV events. No previous study has examined the relationship between sedentary behaviour and endothelial function. We assessed the basal association between conduit artery endothelial function and sedentary behaviour in children, along with the correlation between changes in sedentary behaviour and endothelial function. We studied 116 children (70$: 10.7 ± 0.3; 46#: 10.7 ± 0.3 years) on two occasions; in the summer (June) and late autumn (November). We assessed endothelial function via flowmediated dilation (FMD) using high-resolution Doppler ultrasound. Sedentary behaviour (SB) was assessed using objective uni-axial accelerometry. At baseline, there were no significant differences between girls and boys for any measured variables with the exception of total physical activity time. FMD was not associated with sedentary behaviour in either group or in the cohort as a whole. Although FMD decreased (10.0 ± 4.3–7.9 ± 3.9%, P\0.001) and SB increased (499.1 ± 103.5–559 ± 81.6 min/day, P\0.001) between the seasons, no relationship existed between changes in these variables. Our data suggest that sedentary behaviour and changes in sedentary behaviour are not associated with endothelial function in children.

Is the neighbourhood environment associated with sedentary behaviour outside of school hours among children?

Background Little is known about neighbourhood environments and children’s sedentary behaviour outside school hours.
Purpose This study aims to examine the associations between public open spaces (POS), parent perceptions of the neighbourhood and children’s sedentary behaviours.
Methods Parents reported their child’s television viewing and computer/electronic game time and their perceptions of the physical and social neighbourhood. Children’s sedentary
time was objectively assessed. The closest POS was audited.
Results Cross-sectionally, living near a POS with a water feature and greater parental satisfactionwith POS quality were negatively associated with computer/e-games; greater POS area was negatively associated with TV viewing. Longitudinally, living in a cul-de-sac and greater satisfaction with POS quality were negatively associated with computer/e-games and TV viewing, respectively. Awalking path in the POS was positively associated with computer/e-games.
Conclusion Neighbourhood features appear to positively and negatively influence children’s sedentary behaviours, highlighting the complexity of urban planning on behaviour. Further age- and context-specific studies are required.