Neighborhood environment and physical activity

Introduction Insufficient levels of physical activity are one of the top contributors to global mortality, and it is an important public health priority to increase the proportion of physically active people in the population. The interest in environmental determinants of physical activity has been rapidly increasing over the past few years. However, a majority of the previous literature concerns studies from North America and Australia, and it has often been based on self-reported neighborhood environments and/or on self-reported physical activity. The aim of this thesis was to investigate, for the first time in a Swedish context, the associations between objectively assessed neighborhood characteristics and objectively assessed and self-reported physical activity. Methods This thesis is based on data from the Swedish Neighborhood and Physical Activity (SNAP) study. Neighborhood characteristics were objectively assessed using Geographic Information Systems (GIS). A walkability index consisting of residential density, street connectivity, and land use mix was constructed to define 32 highly and less walkable neighborhoods in the city of Stockholm where data were collected. Physical activity was assessed by accelerometers and by the International Physical Activity Questionnaire (IPAQ). Results The walkability index was associated with higher levels of moderate to vigorous physical activity and walking for transportation and for leisure. The influence of neighborhood walkability was most pronounced during periods of the day when many people are likely to be exposed to their neighborhood environment. When analyzed separately, residential density and land use mix, but not street connectivity, were positively associated with physical activity. Significant proportions of these associations were mediated by vehicle ownership. A positive association was also found between the availability of exercise facilities and time spent in moderate to vigorous physical activity and meeting the physical activity recommendations. None of the associations found in this thesis were modified by individual factors, i.e. people living in dense mixed-use neighborhoods may benefit from these environments regardless of age, gender, income and vehicle ownership status. Conclusions These results add to a growing body of evidence suggesting that policy makers and city planners have the potential, by designing environments that promote physical activity, to increase the levels of physical activity in the population and thereby improve public health