This book offers a comprehensive, evidence-based exploration of the role of movement in combating the global burden of chronic diseases. With conditions such as cardiovascular disease, diabetes, cancer, mental health disorders, arthritis, and obesity on the rise, physical activity is a cornerstone of prevention and management. The book traces the evolution of physical activity from a necessity for survival to a critical component of modern healthcare. It delves into the therapeutic benefits of exercise for various chronic conditions, providing evidence-based guidelines tailored to diverse populations. A dedicated chapter on exercise-program design offers a structured framework for healthcare professionals, fitness experts, and policymakers. The book examines key considerations in measuring physical activity, from traditional assessments to digital tools that enhance accuracy. It explores behavioral and environmental factors influencing participation, addressing barriers through behavioral-change strategies and ecological models. Special attention is given to emerging global challenges, including the impact of COVID-19 on physical activity behaviors and the need for culturally tailored approaches for migrant populations. Bridging research, practical applications, and policy insights, this book is an essential resource for anyone committed to leveraging movement as medicine-an accessible, cost-effective tool for promoting health and longevity in diverse populations and settings.