Physical activity is associated with numerous physical and psychosocial health benefits, yet population levels in the United Kingdom remain low, particularly in lower socioeconomic groups. Socioecological models posit that social and physical environments have independent and interactive influences on physical activity. Although a growing body of literature has examined the independent effect of aspects of the social and physical environment, interactive effects are rarely assessed. In addition, there is limited research specifically examining independent or interactive environmental influences in populations vulnerable to lower levels of physical activity, such as those living in neighbourhoods with high levels of deprivation. This thesis examines the association between quality of the neighbourhood physical environment (aesthetics, maintenance, physical disorder) and social environment (cohesion, safety, social interaction, support, trust, empowerment) on physical activity in adults living in income-deprived communities, using Glasgow as a case study. Cross-sectional analyses, conducted using a socioecological approach, suggested independent and interactive effects of objectively measured physical environmental factors and perceived social environmental factors on neighbourhood-based walking and moderate physical activity. Longitudinal analyses found little evidence that changes in environmental measures predict change in self-reported walking. However, qualitative analyses provided insight into potential causal pathways through a system of interacting environmental factors. Together, findings from this thesis suggest a role for the quality of the neighbourhood physical and social environment on activity, providing some evidence of interactive effects of the neighbourhood social and physical environment. Further research is needed to elucidate causal relationships between the quality of the neighbourhood environment and physical activity. Findings call for a complex systems approach to understanding contextual environmental effects on physical activity in deprived communities
