The influence of exercise on postprandial triacylglycerol metabolism

Trained people exhibit low plasma concentrations of triacylglcyeride (TAG) in both fasted and postprandial states. This mainly reflects enhanced uptak e of TAG into skeletal muscle, via enhanced activity of lipoprotein lipase, the rate-limiting step in TAG removal. Endurance athletes possess a large, well-vascularised muscle mass and this may contribute through the increase d availability of endothelial binding sites for LPL. However, each session of exercise stimulates a delayed increase in LPL activity so that prior exe rcise enhances uptake into muscle. Intramuscular TAG is one source of energ y for muscular contraction so this may serve to replenish muscle nutrient s tores which have been diminished by exercise. Regular, frequent aerobic exe rcise may oppose the atherogenic disturbances to lipoprotein metabolism evi dent during the postprandial period. It may also, by favouring the disposit ion of dietary fatty acids in muscle, improve the matching of fat oxidation to fat intake and hence help with maintenance of a desirable level of body fatness. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.