There is increasing evidence that hepatic lipid content (IntraHepatic Lipid, IHL) markedly increases the risk of metabolic complications, including insulin resistance and cardiovascular events. The investigators hypothesize that the liver is passively taking up free fatty acids (FFA) when the availability is high, thereby leading to an increased storage. To test this hypothesis, the investigators want to manipulate FFA levels, by means of a fasted exercise and recovery protocol, and monitor IHL content and hepatic Adenosine triphosphate (ATP) and inorganic phosphate (Pi) concentrations.