<qa>  What is the only effective treatment for patients with morbid obesity?The only effective treatment for patients with morbid obesity is bariatric surgery. Sudden weight loss following bariatric operations for morbid obesity, such as Roux-en-Y gastric bypass RYGBP can result in a concurrent decrease in lean body mass. However the long-time results weight reduction, elimination co-morbidities are depending on the post operative treatment. Aerobic physical exercising APE is well accepted in conservative treatment of obesity as well as of diabetes mellitus type 2 DM. The aim of this study was to assess the efficiency of APE on weight loss, body composition and co-morbidities in patients after laparoscopic Roux-en-Y Gastric bypass RYGBP. 