Part 1 PREOPERATORY. -- Chapter 1. Relationship of sedentary lifestyles with obesity and co-morbidities -- Chapter 2. Types of physical activity -- Chapter 3. Level of physical activity in the morbidly obese patient -- Chapter 4. Physical activity and body composition -- Chapter 5. Preoperative physical activity and nutrition -- Chapter 6. Benefit of physical activity before surgery: Improvement of comorbidities and reduction of operative risk -- Chapter 7. Preoperative physical activity programs -- Part 2 POSTOPERATIVE. -- Chapter 8. Postoperative physical activity in the bariatric surgery patient -- Chapter 9. Postoperative physical activity and nutrition -- Chapter 10. When to start postoperative physical activity -- Chapter 11. Physical activity and abdominal wall complications (hernias) -- Chapter 12. Effect of physical activity after bariatric surgery on weight loss and improvement of comorbidities in the short and long term -- Chapter 13. Physical activity and alterations of bone metabolism and sarcopenia -- Chapter 14. Types of recommended physical activity -- Chapter 15. Implementation of controlled physical activity programs -- Chapter 16. Physical activity within ERAS . .