Sedentary living is prevalent in society, despite§evidence on the health benefits of exercise and§physical activity. Against this background, the§workplace can provide a key setting from which to§promote lifestyle health improvement. There are§various opportunities, perspectives, and outcomes to§be explored in the evaluation of workplace physical§activity interventions. This book reflects the§complexity of evaluation, using a multi-perspective§approach and behavioural theory to explore the§potential effectiveness of interventions. The§comparison of lifestyle activity messages (moderate§intensity) and structured ones (more vigorous§intensity) is a major theme. Three methodological§approaches are used: a systematic review of evidence,§a qualitative study of employer views, and surveys of§employee responses to different interventions. The§book offers new insight into motivations and barriers§relating to potential management support for, and§employee participation in, workplace physical§activity interventions. It also demonstrates the§usefulness of adopting a rigorous exploratory§research approach. It is addressed to researchers§and decision-makers alike.