This book provides up-to-date evidence-based information on why and how to implement exercise intervention in the treatment of obesity. It starts with a description of the epidemiology of obesity, how to execute pre-participation screening in the obese, and the impact of caloric intake restriction vs exercise training in obese subjects. Next, a detailed description of exercise physiology in obesity is provided, followed by motivation techniques, the impact of training modalities on adipose tissue mass loss, and an exploration of factors related to the heterogeneity of adipose tissue mass loss in the obese when following exercise interventions. In final, the impact of emerging concepts in current exercise prescription for the obese, such as exercise in fasting condition, is covered. This book is dedicated to healthcare professionals and researchers dealing with obesity patients participating in exercise interventions. Moreover, this book could be a support to anyone with great interest for exercise physiology and exercise therapy in obesity.