NAFLD and Physical Exercise: Ready, Steady, Go!

Abstract

Along with the increase in obesity and type 2 diabetes, the non-alcoholic fatty liver disease (NAFLD) incidence is escalating, thus becoming a leading cause of liver cirrhosis and a significant burden of liver-related outcomes. Since there is no pharmacotherapy available to address the NAFLD, the most effective solutions seem to be lifestyle changes centered on physical activity. Exercise could mediate its beneficial effects directly on the liver and indirectly via extrahepatic pathways, forming a dose-response relationship with NAFLD in terms of prevalence and disease severity. Health-enhancing physical activity (HEPA) levels are mainly needed to exert beneficial effects in obese subjects, while even a small amount of exercise can be beneficial for lean individuals to prevent NAFLD. This mini-review addresses three major points regarding physical activity and NAFLD: prevention, treatment, and extrahepatic benefits, offering recommendations on type and intensity of exercise in liver disease.

HIIT and MICT attenuate high-fat diet-induced hepatic lipid accumulation and ER stress via the PERK-ATF4-CHOP signaling pathway

“…In general, caloric restriction is the most important dietary intervention and has the biggest impact on reducing weight and improving liver conditions [ 2 ]. Increased physical activities have also been shown to reduce hepatic steatosis, visceral adipose tissue, and plasma free fatty acids, decreasing the likelihood of developing NAFLD and NASH [ 5 , 10 , 12 ].…”

“…In recent times, high-intensity interval training (HIIT) has become a popular alternative, primarily because of its time efficiency. Numerous studies have demonstrated that exercise training improves systemic markers of liver function and intrahepatic fat in mild-to-advanced NAFLD [ 5 , 10 , 12 ]. Data from an animal study showed that knee loading significantly decreased the histological severity of hepatic steatosis and downregulated biomarkers related to ER stress (e.g., GRP78, p-eIF2α, and ATF4) compared to those of obese mice [ 23 ].…”

Croatian guidelines for the diagnosis and treatment of nonalcoholic fatty liver disease

“…Although there are no controlled studies in a large number of subjects on the effects of physical activity on NAFLD, and the optimal duration, type and intensity of activity as well as long-term effects of physical activity on the course and outcome of NAFLD have not been completely defined, physical activity is a significant measure in changing an unhealthy lifestyle ( 1 , 7 , 80 , 82 , 87 - 90 ). According to the results available, in patients with >150/min of physical activity weekly or an increase in total activity by >60 minutes/week, reduction in ALT was observed regardless of weight loss ( 1 , 80 , 89 , 90 ).…”

A Greater Improvement of Intrahepatic Fat Contents after 6 Months of Lifestyle Intervention Is Related to a Better Oxidative Stress and Inflammatory Status in Non-Alcoholic Fatty Liver Disease

“…Currently, there is no drug therapy that can be formulated for treating NAFLD. A combination of a healthy diet, such as Mediterranean diet [ 21 ], and increased physical activity [ 22 ] remains the mainstay in the management of NAFLD. Thus, lifestyle intervention can be effective for treating NAFLD patients, including a healthy diet and increased physical activity [ 23 ].…”