Exercise Training as Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing health epidemic in developed countries with increased prevalence in obese and diabetic populations. Exercise is an established and essential component of lifestyle modification for NAFLD disease management. Despite numerous studies reporting exercise-mediated improvements in NAFLD, there remains a large gap in our knowledge of how to optimize exercise prescriptions and whether the benefits of exercise extend beyond improvements in liver fat. In this review, we summarize studies that have investigated the independent effects of exercise training on liver enzymes, hepatic fat, and histologic markers in NAFLD. Overall, 12-weeks of aerobic, resistance, the combination of aerobic and resistance, and novel training modalities, including acceleration and hybrid training, significantly improve liver enzymes and hepatic fat. The greatest benefits in NAFLD may occur through the combination of aerobic and resistance training that targets both cardiorespiratory fitness, and mediators of skeletal muscle, known as myokines. Understanding the role of myokines in the beneficial effects of exercise in NAFLD may identify future therapeutic targets that can be modified with tailored exercise prescriptions