Liver transplantation is an accepted therapy for end-stage liver failure. Although the surgery clearly increases physical functioning compared to pre-transplant levels, patients continue to experience significant limitations in physical functioning and frequently report symptoms of muscle weakness. They are at risk for excess weight gain, and cardiovascular risk is elevated. Typically patients are followed for functioning, with little attention and no interventions to improve physical fitness or minimize weight gain and cardiovascular risk. Exercise training is known to increase physical function in other populations. This study is a randomized clinical trial to determine the effects of an intervention of diet modification and exercise training on physical fitness, cardiovascular risk, and quality of life in liver transplant recipients. The intervention will be initiated at 3 months post transplant and testing performed at 3, 6, and 12 months. Exercise will be individually prescribed for independent walking or cycling. The dietary intervention will be based on the NCEP recommendations with the goal of achieving caloric balance to maintain body weight within ideal weight +/- 10%. Both interventions will be aggressively monitored to maximize adherence using recording logs, regular phone follow-up, and regular clinic visits. Primary outcomes are: measures of physical fitness (cardiorespiratory fitness, muscle strength, body composition); quality of life/well-being; and cardiovascular risk profile. Data analysis techniques will test the effectiveness of the intervention as well as determine the relationship of several measured variables to quality of life/well-being. This study is needed to demonstrate the impact of exercise and dietary interventions in optimizing physical fitness and qualify of life over and above any improvements that may result from liver transplant alone and to reduce cardiovascular risk following this surgical procedure.