This study is a randomised, controlled, unblinded, clinical intervention trial consisting of 12 weeks of aerobic exercise training. Thirty persons with chronic hepatitis B (CHB) and hepatic steatosis are randomised to either aerobic exercise training (intervention group, n=15) or no intervention (control group, n=15). The study will investigate the effects of the exercise intervention on the liver and the hypothesis is that the exercise group will reduce the fat-fraction of the liver after the intervention.

Primary aim: To investigate whether regular aerobic exercise training will decrease the fat-fraction of the liver in persons with CHB and hepatic steatosis shown by magnetic resonance imaging (MRI) by use of Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation (IDEAL-IQ). Secondary aim: To investigate the effects of aerobic exercise training on hepatokine secretion in persons with CHB and hepatic steatosis. Also, to investigate if regular physical exercise will improve lipid- and glucose metabolism, liver status, markers of inflammation, body composition, and blood pressure. Study participants will undergo pre and post the interventioon: Clinical examination with ECG, blood pressure measurements, blood sampling, oral glucose tolerance test, a hormone infusion of somatostatin and glucagon, -increasing the glucagon/insulin ratio mimicking an acute exercise bout, measuring the effect on circulating hepatokines and cytokines, fibroscan, VO2-max test, DXA scan, AX3 activity monitoring, nail fold capillaryscopy, IQOLA SF-36 and IPAQ-SF questionnaire, 24H food intake registration, MRI scan of the liver and optional liver biopsy. 6 and 12 months follow-up is planned. The exercise intervention will be randomised 1:1 with no stratification: The training program includes three weekly supervised training sessions of 40 minutes/session over 12 weeks. Participants are instructed not to change their lifestyles during the intervention.