 Physical exercise has been identified as a major beneficial factor in the management of patients suffering from many chronic diseases especially cancer and in the context of cardiac or pulmonary transplantation. It contributes to an improvement of the quality of life and decreases treatment side effects and mortality. Aerobic fitness is constantly altered in cirrhotic patients and correlated to the severity of the hepatic disease. Moreover, in this setting, other etiological factors may be added like chronic obstructive bronchitis and alcoholic cardiomyopathy. In this population, muscle abnormalities with fatigue and cramps have been described. Muscle weakness in this condition may be comparable to that described in patients with chronic obstructive bronchitis and contributes to the decrease of aerobic fitness. Different causes such as muscle deconditioning, hypoxemia, denutrition, anti-rejection drugs increase this phenomenon after liver transplantation. Finally, the aerobic capacity or VO2max is a prognostic factor for survival and is linked to the number and the length of hospitalizations after liver transplantation LT. 