Exercise, postprandial triacylglyceridemia, and cardiovascular disease risk.

An elevation of plasma triacylglycerides (TAG) is a well recognized cardiovascular risk factor. Less appreciated is that high and prolonged elevations in TAG in the postprandial (PP) phase is also a risk factor. Given that we spend approximately 18 hrs a day in the PP state, this is particularly critical. The elevation is due to both cylomicron and very low density lipoprotein TAG. It is thought that enhancing the concentrations of these lipoproprotein fractions increases the production of smaller, more dense low density lipoprotein and that this leads to increased cardiovascular disease risk. The PP TAG response is greater in men, in obese individuals, and in type 2 diabetics. It has been reported repeatedly that exercise the day before ingestion of a high fat meal is associated with a marked dampening of the PP TAG rise. The mechanisms for this are not clear and do not appear to be due to changes in the exercised muscle itself. There is some speculation that the production of plasma TAG may be decreased. The exercise benefits are lost within 3 days. The minimum exercise required has not been determined, but even 30 min of intermittent aerobic exercise or mild resistance exercise has a positive effect. This demonstrates a clear benefit from an active lifestyle and one that does not require intense exercise or months of training.