Effects of strategies to promote children's physical activity on potential mediators

The aim of this paper is to review evidence of the effectiveness of interventions that present physical activity outcomes and potential mediators of behavioural change among 4–12-year-old children. A systematic search of electronic databases for original research articles published in peer-review journals between January 1985 and the end of June 2006 was carried out. A total of 19 studies that reported intervention effects on physical activity and mediators of behavioural change were identified. The most common mediators reported included physical activity knowledge or beliefs (11 studies); self-efficacy (8 studies); and enjoyment or preference for physical activity (6 studies). Less frequently reported mediators included attitudes, behavioural capability, intentions, outcome expectancies, social norms, social support and self-concept. Seven of the 11 interventions that reported intervention effects on knowledge/beliefs stated positive changes in this mediator. Four of the eight studies that reported intervention effects on self-efficacy had significant improvements; however, only two out of six interventions reported significant improvements in physical activity enjoyment or preference. None of the studies reviewed reported whether changes in these constructs mediated changes in children's physical activity behaviours. Although more than half of the studies reviewed reported a positive intervention effect on children's physical activity, no study carried out a mediating analysis to attempt to identify the mechanisms of change. Future research should more clearly identify the mediators of behavioural change that are being targeted and whether this explains intervention effects.

"Tell us something new!" : the response of planning and transport professionals to public health guidance on the built environment and physical activity

A large proportion of non-communicable disease can be attributed to modifiable risk factors such as poor nutrition and physical inactivity. We present data on planning and transport practitioners' perceptions and responses to government public health guidance aimed at modifying environmental factors to promote physical activity. This study was informed by questions on the role of evidence-based guidance, the views of professionals towards the guidance, the links between guidance and existing legislation and policy and the practicality of guidelines. A key informant 'snowball' sampling technique was used to recruit participants from the main professional planning organisations across England. Seventy-six people were interviewed in eight focus groups. We found that evidence-based public health guidance is a new voice in urban and town planning, although much of the advice is already reflected by the 'accepted wisdom' of these professions. Evidence-based health guidance could be a powerful driver affecting planning practice, but other legislated planning guidance may take priority for planning and transport professionals.

Understanding participation in sport and physical activity amongst children and adults : A systematic review of qualitative studies

Qualitative research may be able to provide an answer as to why adults and children do or do not participate in sport and physical activity. This paper systematically examines published and unpublished qualitative research studies of UK children's and adults' reasons for participation and non-participation in sport and physical activity. The review covers peer reviewed and gray literature from 1990 to 2004. Papers were entered into review if they: aimed to explore the participants' experiences of sport and physical activity and reasons for participation or non-participation in sport and physical activity, collected information on participants who lived in the United Kingdom and presented data collected using qualitative methods. From >1200 papers identified in the initial search, 24 papers met all inclusion criteria. The majority of these reported research with young people based in community settings. Weight management, social interaction and enjoyment were common reasons for participation in sport and physical activity. Concerns about maintaining a slim body shape motivated participation among young girls. Older people identified the importance of sport and physical activity in staving off the effects of aging and providing a social support network. Challenges to identity such as having to show others an unfit body, lacking confidence and competence in core skills or appearing overly masculine were barriers to participation.

Occupational and non-occupational physical activity and the social determinants of physical activity : results from the Health Survey for England

Background: This article aims to examine the relative contribution of occupational activity to English adults’ meeting of government recommendations for physical activity (PA).

Methods: Data were extracted from a cross-sectional survey of householders in the UK via the Health Survey for England.¹ In total, 14,018 adult participants were included in the analysis. Multivariate logistic regression was used to examine the odds of achieving PA recommendations with and without including occupational activity and to examine the contribution of gender and social and demographic characteristics.

Results: When occupational PA was included, 36% of men and 25% of women were active at the recommended level. Once occupational PA was removed, these proportions were 23% and 19%, respectively. These results were socially patterned, most notably by age and gender.

Conclusions: Occupational PA provides a substantial contribution to those meeting the government target for PA.

The burden of physical activity-related ill health in the UK

Background: Despite evidence that physical inactivity is a risk factor for a number of diseases, only a third of men and a quarter of women are meeting government targets for physical activity. This paper provides an estimate of the economic and health burden of disease related to physical inactivity in the UK. These estimates are examined in relation to current UK government policy on physical activity.

Methods: Information from the World Health Organisation global burden of disease project was used to calculate the mortality and morbidity costs of physical inactivity in the UK. Diseases attributable to physical inactivity included ischaemic heart disease, ischaemic stroke, breast cancer, colon/rectum cancer and diabetes mellitus. Population attributable fractions for physical inactivity for each disease were applied to the UK Health Service cost data to estimate the financial cost.

Results: Physical inactivity was directly responsible for 3% of disability adjusted life years lost in the UK in 2002. The estimated direct cost to the National Health Service is £1.06 billion.

Conclusion: There is a considerable public health burden due to physical inactivity in the UK. Accurately establishing the financial cost of physical inactivity and other risk factors should be the first step in a developing national public health strategy.

Life-change events and participation in physical activity : a systematic review

Physical inactivity and related diseases are of global public health concern. In many developing countries, levels of health promoting physical activity (PA) are falling despite government initiatives. Previous work has identified that periods of transition across a life course, or ‘life-change events’ have implications for drop out from PA. As yet, there has been little work to understand the life course as a whole and to furnish a complete list of possible life changes that might affect participation in PA. Our paper presents a review of the published literature in which life events have been studied in relation to their effect on participation in PA. A literature search was conducted for papers published between 1977 and April 2007 and referenced in Pubmed. Papers were reviewed if they; reported the effect of a life-change event; had PA as an outcome; reported results in English; and reported results from observational studies. The references for studies identified during this first phase were searched for further papers. Eighty-seven papers were identified as potentially relevant on the basis of title, of which 19 papers met the inclusion criteria on the basis of full text. Five life changes were identified; change in employment status; change in residence; change in physical status; change in relationships; and change in family structure. It was noted that few longitudinal studies examined PA both before and after a life event. A list of possible life events which might effect participation in PA is presented. This paper represents a first step towards a detailed programme of work on life-change events and PA.

Physical activity and environment programme guidance : fieldwork report

This quick reference guide presents the recommendations on ‘Promoting and creating built or natural environments that encourage and support physical activity’. It is for NHS and other professionals who have a direct or indirect role in – and responsibility for – the built or natural environment. This includes those working in local authorities and the education, community, voluntary and private sectors. It may also be of interest to members of the public. The guidance offers the first national, evidence-based recommendations on how to improve the physical environment to encourage physical activity. It demonstrates the importance of such improvements and the need to evaluate how they impact on the public’s health.

Diet, physical activity and obesity statistics

This publication provides statistics on diet, physical activity and obesity as these relate to the incidence and prevalence of CVD.

Family influences on children's physical activity and fruit and vegetable consumption

Background : There is evidence of a clustering of healthy dietary patterns and physical activity among young people and also of unhealthy behaviours. The identification of influences on children's health behaviors, particularly clustered health behaviors, at the time at which they develop is imperative for the design of interventions. This study examines associations between parental modelling and support and children's physical activity (PA) and consumption of fruit and vegetables (FV), and combinations of these behaviours.

Methods : In 2002/3 parents of 775 Australian children aged 10–12 years reported how frequently their child ate a variety of fruits and vegetables in the last week. Children wore accelerometers for eight days during waking hours. Parental modelling and parental support (financial and transport) were self-reported. Binary logistic and multinomial logistic regression analyses examined the likelihood of achieving ≥ 2 hours of PA per day (high PA) and of consuming ≥ 5 portions of FV per day (high FV) and combinations of these behaviors (e.g. high PA/low FV), according to parental modelling and support.

Results : Items of parental modelling and support were differentially associated with child behaviours. For example, girls whose parents reported high PA modelling had higher odds of consuming ≥ 5 portions of FV/day (OR = 1.95, 95% CI = 1.32–2.87, p < 0.001). Boys whose parents reported high financial support for snacks/fast foods had higher odds of having 'high PA/low FV' (OR = 2.0, 95% CI = 1.1–3.7).

Conclusion : Parental modelling of and support for physical activity and fruit and vegetable consumption were differentially associated with these behaviours in children across behavioural domains and with combinations of these behaviours. Promoting parents' own healthy eating and physical activity behaviours as well encouraging parental modelling and support of these behaviours in their children may be important strategies to test in future research.

Contrasting longitudinal and cross-sectional relationships between insulin resistance and percentage of body fat, fitness, and physical activity in children—the LOOK study

Background: Knowledge of individual changes in insulin resistance (IR) and longitudinal relationships of IR with lifestyle-associated factors are of important practical significance, but little longitudinal data exist in asymptomatic children. We aimed to determine (a) changes in the homeostatic model of insulin resistance (HOMA-IR) over a 2-yr period and (b) comparisons of longitudinal and cross-sectional relationships between HOMA-IR and lifestyle-related risk factors.

Methods: Our subjects, 241 boys and 257 girls, were assessed at age 8.1 yr (SD 0.35) and again 2 yr later for fasting blood glucose and insulin, dual X-ray absorptiometry-assessed percentage of body fat (%BF), pedometer-assessed physical activity (PA), and cardio-respiratory fitness (CRF) by multistage running test.

Results: HOMA-IR was initially 9% greater in girls than boys and 27% greater 2 yr later. There was no evidence of longitudinal relationships between HOMA-IR and %BF in boys or girls, despite significant cross-sectional relationships (p < 0.001). In boys, there was evidence of a longitudinal relationship between HOMA-IR and both PA (p < 0.001) and CRF (p = 0.05). In girls, we found a cross-sectional relationship between HOMA-IR and CRF (p < 0.001).

Conclusions: HOMA-IR increases between 8 and 10 yr of age and to a greater extent in girls. Longitudinal, unlike cross-sectional, relationships do not support the premise that body fat has any impact on HOMA-IR during this period or that PA or CRF changes affect HOMA-IR in girls. These data draw attention to difficulties in interpreting observational studies in young children.