This book examines the new knowledge that has been gained from the objective monitoring of habitual physical activity by means of pedometers and accelerometers. It reviews current advances in the technology of activity monitoring and details advantages of objective monitors relative to physical activity questionnaires. It points to continuing gaps in knowledge, and explores the potential for further advances in the design of objective monitoring devices.

Epidemiologists have studied relationships between questionnaire assessments of habitual physical activity and various medical...