Exercise and postprandial lipid metabolism - an analysis of the current evidence

Exaggerated levels of postprandial lipaemia are implicated in the atherosclerotic disease process and are a risk marker for cardiovascular disease. Postprandial lipaemia is reduced following an exercise session and the energy expended during exercise is an important determinant of the extent of triglyceride (TG) lowering. Interestingly, the TG-lowering effect of an exercise session cannot be replicated by restricting energy intake to elicit a similar level of energy deficit. It seems likely that the low levels of postprandial lipaemia experienced by endurance-trained individuals are largely due to the TG-lowering effects of individual exercise sessions, rather than long-term training adaptations, although trained individuals may also benefit from the hypotriglyceridaemic effects of having low levels of body fat. Increased lipoprotein lipase-mediated TG clearance and reduced hepatic TG secretion are both likely to contribute to the TG reductions seen following an exercise session, but the relative importance of these two mechanisms is likely to depend on a number of factors including the energy expended during exercise and the training status of the exercising subject. Further study is needed to determine the effectiveness of exercise in reducing postprandial lipaemia in groups at increased risk for cardiovascular disease and to assess the impact of these lipoprotein changes on other aspects of cardiovascular risk.