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Pearson N.,Loughborough University | Braithwaite R.E.,Humboldt State University | Biddle S.J.H.,Loughborough University | Biddle S.J.H.,Lifestyle and Physical Activity Biomedical Research Unit | And 2 more authors.
Obesity Reviews | Year: 2014

Physical activity and sedentary behaviour are associated with metabolic and mental health during childhood and adolescence. Understanding the inter-relationships between these behaviours will help to inform intervention design. This systematic review and meta-analysis synthesized evidence from observational studies describing the association between sedentary behaviour and physical activity in young people (<18years). English-language publications up to August 2013 were located through electronic and manual searches. Included studies presented statistical associations between at least one measure of sedentary behaviour and one measure of physical activity. One hundred sixty-three papers were included in the meta-analysis, from which data on 254 independent samples was extracted. In the summary meta-analytic model (k=230), a small, but significant, negative association between sedentary behaviour and physical activity was observed (r=-0.108, 95% confidence interval [CI]=-0.128, -0.087). In moderator analyses, studies that recruited smaller samples (n<100, r=-0.193, 95% CI=-0.276, -0.109) employed objective methods of measurement (objectively measured physical activity; r=-0.233, 95% CI=-0.330, -0.137) or were assessed to be of higher methodological quality (r=-0.176, 95% CI=-0.215, -0.138) reported stronger associations, although effect sizes remained small. The association between sedentary behaviour and physical activity in young people is negative, but small, suggesting that these behaviours do not directly displace one another. © 2014 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of International Association for the Study of Obesity.


Brown H.E.,University of Queensland | Pearson N.,Loughborough University | Pearson N.,Lifestyle and Physical Activity Biomedical Research Unit | Braithwaite R.E.,Humboldt State University | And 4 more authors.
Sports Medicine | Year: 2013

Context: Evidence suggests chronic physical activity (PA) participation may be both protective against the onset of and beneficial for reducing depressive symptoms. Objective: The aim of this article is to assess the impact of PA interventions on depression in children and adolescents using meta-analysis. Data sources: Published English language studies were located from manual and computerized searches of the following databases: PsycInfo, The Cochrane Database of Systematic Reviews and The Cochrane Central Register of Controlled Trials, Trials Register of Promoting Health Interventions (TRoPHI; EPPI Centre), Web of Science and MEDLINE. Study selection: Studies meeting inclusion criteria (1) reported on interventions to promote or increase PA; (2) included children aged 5-11 years and/or adolescents aged 12-19 years; (3) reported on results using a quantitative measure of depression; (4) included a non-physical control or comparison group; and (5) were published in peer-reviewed journals written in English, up to and including May 2011 (when the search was conducted). Data extraction: Studies were coded for methodological, participant and study characteristics. Comprehensive Meta-Analysis version-2 software was used to compute effect sizes, with subgroup analyses to identify moderating characteristics. Study quality was assessed using the Delphi technique. Results: Nine studies were included (n = 581); most were school-based randomized controlled trials, randomized by individual. Studies used a variety of measurement tools to assess depressive symptoms. The summary treatment effect was small but significant (Hedges' g = -0.26, standard error = 0.09, 95% confidence intervals = -0.43, -0.08, p = 0.004). Subgroup analyses showed that methodological (e.g. studies with both education and PA intervention; those with a higher quality score; and less than 3 months in duration) and participant characteristics (e.g. single-gender studies; those targeting overweight or obese groups) contributed most to the reduction in depression. Conclusions: There was a small significant overall effect for PA on depression. More outcome-focused, high-quality trials are required to effectively inform the implementation of programmes to reduce depressive symptoms in children and adolescents. © 2012 Springer International Publishing Switzerland.


Tang J.,University of Exeter | Abraham C.,University of Exeter | Greaves C.,University of Exeter | Yates T.,Lifestyle and Physical Activity Biomedical Research Unit | Yates T.,University of Leicester
Journal of Medical Internet Research | Year: 2014

Background: A wide range of self-directed weight-loss interventions are available, providing users with a variety of tools delivered through various formats to regulate weight-related behavior patterns. However, it is unclear how effective self-directed interventions are and how they promote weight loss and weight maintenance. Objective: A systematic review of reviews was conducted to examine the effectiveness of such interventions and to identify intervention content associated with effectiveness. Methods: MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Library for systematic reviews were searched from 2000-2012 for reviews of the effectiveness of self-directed interventions on weight loss and weight maintenance in adults. Two reviewers used predefined inclusion criteria to select relevant reviews and assess their quality using the Overview Quality Assessment Questionnaire (OQAQ). We extracted data on effectiveness and on relationships between intervention characteristics and effectiveness. Results: Twenty reviews were included and quality assessed. Findings relevant to self-directed interventions, including interactive websites, smartphone applications, and text messaging (short message service, SMS) were summarized. Findings were mixed but promising. For example, one review of Internet-based interventions found that, when used in conjunction with standard weight loss programs, these interventions resulted in a significant average increase in weight loss of 1.5 kg over evaluation periods. Unfortunately, only 7 of 20 reviews were of high methodological quality according to OQAQ scores, and only 4 employed meta-analyses. Few reviews linked intervention content to effectiveness. Conclusions: Current evidence suggests that self-directed interventions can independently promote weight loss and can augment interventions involving personal contact. Particular change techniques and delivery modes including individualized feedback, email counseling, and online social support appear to enhance effectiveness. Further reviews of the content of self-directed weight-loss intervention studies are needed to clarify which change techniques delivered through which delivery formats optimize intervention effectiveness.


Hobbs M.,Leeds Beckett University | Pearson N.,Loughborough University | Foster P.J.,Loughborough University | Biddle S.J.H.,Loughborough University | And 2 more authors.
British Journal of Sports Medicine | Year: 2015

Background Sedentary behaviour and its association with dietary intake in young people and adults are important topics and were systematically reviewed in 2011. There is a need to update this evidence given the changing nature of sedentary behaviour and continued interest in this field. This review aims to assist researchers in better interpreting the diversity of findings concerning sedentary behaviour and weight status. Objective To provide an update of the associations between sedentary behaviour and dietary intake across the lifespan. Methods Electronic databases searched were MEDLINE, PsychInfo, Cochrane Library, Web of Science and Science Direct for publications between January 2010 and October 2013, thus updating a previous review. Included were observational studies assessing an association between at least one sedentary behaviour and at least one aspect of dietary intake in preschool children (<5 years), school-aged children (6-11 years), adolescents (12-18 years) and adults (>18 years). Results 27 papers met inclusion criteria (preschool k=3, school-aged children k=9, adolescents k=15, adults k=3). For all three groups of young people, trends were evident for higher levels of sedentary behaviour, especially TV viewing, to be associated with a less healthful diet, such as less fruit and vegetable and greater consumption of energy-dense snacks and sugar sweetened beverages. Data for the three studies with adults were less conclusive. Conclusions Sedentary behaviour continues to be associated with unhealthy diet in young people in mostly cross-sectional studies. More studies utilising a prospective design are needed to corroborate findings and more studies are needed with adults.


Biddle S.J.H.,Loughborough University | Biddle S.J.H.,Lifestyle and Physical Activity Biomedical Research Unit | Petrolini I.,Loughborough University | Pearson N.,Loughborough University
British Journal of Sports Medicine | Year: 2014

Background: Leisure time is increasingly spent in sedentary pursuits such as screen-viewing (eg, television/DVD viewing and computer use), motorised travel, school/work and sitting-based socialising (eg, social media and chatting). Sedentary screen time, particularly TV, appears to play an important role in the aetiology of obesity due to its co-occurrence with other unhealthy behaviours such as snacking on energy-dense foods, low levels of physical activity and inadequate sleep. More information is needed on how to reduce sedentary behaviours. Most interventions have focused on young people and a number of systematic reviews exist on this topic. Objective: To synthesise systematic reviews and metaanalyses of interventions aimed at decreasing sedentary behaviours among children and adolescents. Methods: Papers were located from computerised and manual searches. Included articles were English language systematic reviews or meta-analyses of interventions aiming at reducing sedentary behaviour in children (<11 years) and adolescents (12-18 years). Results: Ten papers met the inclusion criteria and were analysed. All reviews concluded some level of effectiveness in reducing time spent in sedentary behaviour. When an effect size was reported, there was a small but significant reduction in sedentary time (highest effect size=-0.29; CI -0.35 to -0.22). Moderator analyses showed a trend favouring interventions with children younger than 6 years. Effective strategies include the involvement of family, behavioural interventions and electronic TV monitoring devices. Conclusions: Results from systematic reviews and meta-analyses show that interventions to reduce children's sedentary behaviour have a small but significant effect. Future research should expand these findings examining interventions targeting different types of sedentary behaviours and the effectiveness of specific behaviour change techniques across different contexts and settings.


Mansoubi M.,Loughborough University | Pearson N.,Loughborough University | Pearson N.,Lifestyle and Physical Activity Biomedical Research Unit | Biddle S.J.H.,Loughborough University | And 4 more authors.
Preventive Medicine | Year: 2014

To ascertain, through a systematic review, the associations between sedentary behaviour (SB) and physical activity (PA) among adults aged 18-60. years. Studies published in English up to and including June 2013 were located from computerized and manual searches. Studies reporting on at least one measure of SB and an association with one measure of PA were included. 26 studies met the inclusion criteria. Six studies examined associations between SB and PA prospectively, and 20 were cross-sectional. The most commonly assessed subtype of sedentary behaviours were television viewing (11 studies), total sedentary time (10), total sitting time (4), general screen time (3) and occupational sedentary time (2). All studied types of SB were associated with lower levels of PA in adults. Findings of this review suggest inverse associations between SB and PA were weak to moderate. Objective monitoring studies reported larger negative associations between SB and light intensity activity. Current evidence, though limited, supports the notion that sedentary behaviour displaces light intensity activity. © 2014 Elsevier Inc.


Pearson N.,Loughborough University | Braithwaite R.,Humboldt State University | Biddle S.J.H.,Loughborough University | Biddle S.J.H.,Lifestyle and Physical Activity Biomedical Research Unit
Academic Pediatrics | Year: 2015

BACKGROUND: Research has shown that a clear decline in physical activity among girls starting in early adolescence. Therefore, adolescent girls have been identified as a key target population for physical activity behavior change. The quantification of intervention effectiveness for this group has not been previously reported in a meta-analysis, and this therefore was the objective of the current meta-analysis. STUDY SELECTION: Included were interventions in which the main component, or 1 of the components, was aimed at promoting physical activity through behavior change in any setting. Interventions had to include a non-physical activity control group or comparison group, and include a quantitative outcome assessment of physical activity behavior in girls aged 12 to 18 years. DATA SOURCES: Science Direct, PubMed, PsychINFO, Web of Science, Cochrane Libraries, and EPPI Centre databases were searched up to and including May 2013. DATA EXTRACTION AND SYNTHESIS: Forty-five studies (k = 34 independent samples) were eligible from an initial 13,747 references. A random-effects meta-analysis was conducted. RESULTS: The average treatment effect for adolescent girls involved in physical activity interventions was significant but small (g = 0.350, 95% confidence interval 0.12, 0.58, P < .001). Moderator analyses showed larger effects for interventions that were theory based, performed in schools, were girls only, with younger girls, used multicomponent strategies, and involved targeting both physical activity and sedentary behavior. CONCLUSIONS: Interventions to increase physical activity in adolescent girls show small but significant effects, suggesting that behavior change may be challenging. Results suggest some approaches that appear to be successful. Copyright © 2015 by Academic Pediatric Association.


Wilmot E.G.,University of Leicester | Edwardson C.L.,University of Leicester | Edwardson C.L.,Loughborough University | Achana F.A.,University of Leicester | And 10 more authors.
Diabetologia | Year: 2012

Aims/hypothesis Sedentary (sitting) behaviours are ubiquitous in modern society. We conducted a systematic review and meta-analysis to examine the association of sedentary time with diabetes, cardiovascular disease and cardiovascular and all-cause mortality. Methods Medline, Embase and the Cochrane Library databases were searched for terms related to sedentary time and health outcomes. Cross-sectional and prospective studies were included. RR/HR and 95% CIs were extracted by two independent reviewers. Data were adjusted for baseline event rate and pooled using a random-effects model. Bayesian predictive effects and intervals were calculated to indicate the variance in outcomes that would be expected if new studies were conducted in the future. Results Eighteen studies (16 prospective, two cross-sectional) were included, with 794,577 participants. Fifteen of these studies were moderate to high quality. The greatest sedentary time compared with the lowest was associated with a 112% increase in the RR of diabetes (RR 2.12; 95%credible interval [CrI] 1.61, 2.78), a 147%increase in the RR of cardiovascular events (RR 2.47; 95% CI 1.44, 4.24), a 90% increase in the risk of cardiovascular mortality (HR 1.90; 95%CrI 1.36, 2.66) and a 49%increase in the risk of all-cause mortality (HR 1.49; 95% CrI 1.14, 2.03). The predictive effects and intervals were only significant for diabetes. Conclusions/interpretation Sedentary time is associated with an increased risk of diabetes, cardiovascular disease and cardiovascular and all-cause mortality; the strength of the association is most consistent for diabetes. © Springer-Verlag 2012.


Yates T.,Lifestyle and Physical Activity Biomedical Research Unit | Yates T.,University of Leicester | Yates T.,Leicester General Hospital | Schulte P.J.,Duke University | And 14 more authors.
The Lancet | Year: 2014

Background The extent to which change in physical activity can modify the risk of cardiovascular disease in individuals at high cardiovascular risk is uncertain. We investigated whether baseline and change in objectively-assessed ambulatory activity is associated with the risk of a cardiovascular event in individuals at high cardiovascular risk with impaired glucose tolerance. Methods We assessed prospective data from the NAVIGATOR trial involving 9306 individuals with impaired glucose tolerance who were recruited in 40 countries between January, 2002, and January, 2004. Participants also either had existing cardiovascular disease (if age ≥50 years) or at least one additional cardiovascular risk factor (if age =55 years). Participants were followed-up for cardiovascular events (defi ned as cardiovascular mortality, non-fatal stroke, or myocardial infarction) for 6 years on average and had ambulatory activity assessed by pedometer at baseline and 12 months. Adjusted Cox proportional hazard models quantifi ed the association of baseline and change in ambulatory activity (from baseline to 12 months) with the risk of a subsequent cardiovascular event, after adjustment for each other and potential confounding variables. This study is registered with ClinicalTrials.gov NCT00097786. Findings During 45 211 person-years follow-up, 531 cardiovascular events occurred. Baseline ambulatory activity (hazard ratio [HR] per 2000 steps per day 0.90, 95% CI 0.84-0.96) and change in ambulatory activity (0.92, 0.86-0.99) were inversely associated with the risk of a cardiovascular event. Results for change in ambulatory activity were unaff ected when also adjusted for changes in body-mass index and other potential confounding variables at 12 months. Interpretation In individuals at high cardiovascular risk with impaired glucose tolerance, both baseline levels of daily ambulatory activity and change in ambulatory activity display a graded inverse association with the subsequent risk of a cardiovascular event. Funding Novartis Pharmaceuticals.


Buckley J.P.,University of Chester | Hedge A.,Cornell University | Yates T.,Lifestyle and Physical Activity Biomedical Research Unit | Yates T.,University of Leicester | And 5 more authors.
British Journal of Sports Medicine | Year: 2015

An international group of experts convened to provide guidance for employers to promote the avoidance of prolonged periods of sedentary work. The set of recommendations was developed from the totality of the current evidence, including long-term epidemiological studies and interventional studies of getting workers to stand and/or move more frequently. The evidence was ranked in quality using the four levels of the American College of Sports Medicine. The derived guidance is as follows: for those occupations which are predominantly desk based, workers should aim to initially progress towards accumulating 2 h/day of standing and light activity (light walking) during working hours, eventually progressing to a total accumulation of 4 h/day (prorated to part-time hours). To achieve this, seated-based work should be regularly broken up with standing-based work, the use of sit-stand desks, or the taking of short active standing breaks. Along with other health promotion goals (improved nutrition, reducing alcohol, smoking and stress), companies should also promote among their staff that prolonged sitting, aggregated from work and in leisure time, may significantly and independently increase the risk of cardiometabolic diseases and premature mortality. It is appreciated that these recommendations should be interpreted in relation to the evidence from which they were derived, largely observational and retrospective studies, or short-term interventional studies showing acute cardiometabolic changes. While longer term intervention studies are required, the level of consistent evidence accumulated to date, and the public health context of rising chronic diseases, suggest initial guidelines are justified. We hope these guidelines stimulate future research, and that greater precision will be possible within future iterations.

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