Moderate exercise, postprandial lipaemia and triacylglycerol clearance

Abstract

Background: Moderate intensity exercise reduces postprandial triacylglycerol (TG) concentrations. We tested whether this reflects increased TG clearance. Materials and methods: Eight normotriglyceridaemic men, aged 48.3 ± 7.3 years (mean ± SD), performed two oral fat tolerance tests (blood samples taken in the fasted state and for six hours after a high-fat meal containing 1.00 g fat, 0.97 g carbohydrate, 58 kJ energy kg-1 fat-free body mass) and two intravenous fat tolerance tests (blood samples in the fasted state and after a bolus injection of Intralipid, 0.1 g fat kg-1 body mass). The afternoon before one oral and one intravenous test, subjects walked briskly for 90 min; no exercise was performed before the control tests. Results: Prior exercise reduced fasting TG concentration similarly in the oral (16 ± 7 %) (mean ± SEM) and intravenous (18 ± 7 %) tests, and reduced postprandial TG concentrations in the oral test by 18 ± 6 % (all P < 0.05). However, prior exercise did not increase Intralipid clearance (disappearance curve slopes: control, 4.69 ± 0.49 % min-1; exercise, 4.85 ± 0.40 % min-1). Conclusions: These data suggest that mechanisms other than increased TG clearance mediate the lower postprandial TG concentrations seen after moderate exercise.