Environmental and social influences on physical activity

Obesity in both children and adults is becoming increasingly common in this and other developed countries. Although the precise causes remain unclear, evidence suggests that even fairly small changes in physical activity could help to reverse this damaging trend. Physical activity also reduces risks of heart disease, diabetes, osteoporosis and even some cancers. Unfortunately, levels of activity appear to be decreasing in adults and may also be in children, although there is surprisingly little information available to confirm this. Approaches to increase activity, for example exercise prescriptions from the family doctor, have had limited success. There are many reasons put forward as to why people are inactive and what could be done to encourage activity. These cover such diverse areas as government policy concerning transport through to availability of school playing fields, sports facilities and a pleasant neighbourhood. Some are more easily altered than others. Before making potentially unhelpful and expensive recommendations it is useful to know how sedentary adults and children actually are and which factors (psychological, cultural, environmental and so on) are most strongly associated with inactivity. It would then be logical to target some of these factors in an effort to increase activity.

We propose to measure physical activity in adult volunteers by questionnaire and in 9-10 year old school children by questionnaire and also by using a matchbox sized device called an accelerometer worn on the waist which measures movement rather like a pedometer. The questionnaires will also assess a range of volunteer characteristics thought to be associated with activity including perceptions of the environment. In addition we will assess the built environment eg school and neighbourhood using both direct observation and a geographical information system that contains data on factors such as street lighting, garden size and traffic levels. This will enable the measures of physical activity and the assessment of the environment to be linked for each volunteer. We then plan to interview families to identify the barriers and opportunities to promoting physical activity. Finally we will present the results to interested groups with responsibility for health, children and the environment such as school governors, head teachers, Norfolk Children?s Services and also Cambridge Horizons, Local Authorities and the East of England Development Agency who are responsible for delivering nearly 50,000 new homes and #2.2billion of support infrastructure in the wider vicinity of Cambridge by 2016.

Sedentary living is a major public health problem as it accounts for more than 11 % of all deaths in developed countries and is causally associated with coronary heart disease, diabetes, osteoporosis and some cancers. Interventions aimed at increasing population levels of physical activity have had only modest success and in order to develop effective interventions to halt or reverse the population decline in physical activity, a better understanding of the potentially modifiable determinants of physical activity is required. These physiological, psychological, socio-cultural and environmental determinants operate both at the individual and collective or societal level. In children and adults, numerous studies have focussed on studying individual determinants of health behaviour, whereas the collective determinants have previously received little attention. An unsupportive environment may play a part in the reduction in population levels of physical activity and in the rapid rise of obesity levels. However, there is little published UK data, either in children or adults, on the association between subjectively or objectively assessed environmental determinants and physical activity.

The aims of this study, therefore, are to identify objective and subjective environmental determinants of physical activity in middle-aged adults and to describe the patterns and individual and collective determinants of physical activity in children. In the childhood group, we also aim to describe the perceptions of parents concerning their children?s levels of physical activity and to identify opportunities and barriers to increasing levels of activity. Finally we aim to develop measures of the environmental determinants of activity that can be used in subsequent evaluations of natural experiments of environmental change which may impact on physical activity levels.

The proposed study has four phases; observational studies of the individual and environmental determinants of activity in an existing study of adults (Phase 1) and in a new study of children (phase 2) in an area with detailed previously collated environmental Geographical Information System (GIS) data. Phase 3 is a qualitative study nested within the survey of children to assess parental perceptions of environmental barriers and opportunities for activity. Phase 4 is a formal dissemination to key stakeholders, to inform and influence those involved with the design and maintenance of the built environment, and also the development of new measures to evaluate natural experiments.