27 Yet, the argument that there is a benefit in exercise participation against NAFLD is also supported by data, which demonstrate an inverse correlation between measures of NAFLD and cardiorespiratory fitness.2, 28-30 This is commonly described as maximal aerobic power (VO2max) and typically increases with exercise training (Table 3). However, the association is not apparent in all studies31 including those with lean individuals32; it appears to be independent of BMI but not visceral adiposity2, 28-30 (Table 3). From their 1-year longitudinal

MK-2206 cost cohort study, Suzuki and colleagues noted that normalization of ALT was 2.5 times more likely in those participating in regular exercise (≥once a week) than those who did not.18 Likewise, Huang and coworkers noted improvements in liver histology in patients who reported increasing their PA habits.16 Finally, on the basis of data from their lifestyle intervention, Kantartzis and colleagues also showed that although reduction in hepatic fat was a function of weight loss,

cardiorespiratory fitness was an independent and best predictor of change in hepatic triglyceride, independent of total and visceral adiposity.2 It was suggested that cardiorespiratory Selleck GS-1101 fitness modulates liver fat via effects on hepatic mitochondrial biogenesis, leading to increased lipid oxidation.2 Interestingly, reported habitual selleck screening library PA level and increase in PA levels did not predict the hepatic benefit.2 Research that has examined the efficacy of PA in isolation provides generally favorable evidence for an independent effect in modulating liver tests and liver fat (Tables 1 and

4). In a prospective study in which a subgroup with NASH received exercise prescription without dietary intervention, Sreenivasa Baba et al. found an ∼50% reduction in aminotransferase levels after 3 months. This was associated with a reduction in waist circumference, yet no change in BMI. No changes in ALT or aspartate aminotransferase (AST) were observed in patients who were noncompliant.3 The largest study to examine for possible independent effects of PA in NAFLD showed that 3 months of a behavior change–based intervention significantly improved liver enzymes independent of weight loss.5 In this study, participants who achieved low (60-119 minutes/week) and moderate (120-239 minutes/week) volumes of incidental PA experienced a hepatic benefit, with the greatest improvement in those who increased their PA levels to >150 minutes/week and had improved VO2max.5 Four studies have examined the effect of exercise therapy in isolation on hepatic steatosis (Table 4). Twelve weeks of structured, supervised cycling had no measurable effect on liver fatness as inferred by computed tomography in a mixed cohort of obese and lean individuals.33 This outcome was corroborated by Shojaee-Moradie and colleagues.