title: Postprandial lipemia and chylomicron clearance in athletes and in sedentary men.
abstract: To examine the effects of exercise on postprandial serum triglyceride (TG) metabolism, we measured oral and intravenous fat tolerance and chylomicron-TG half-life in highly trained endurance athletes and in a sedentary control group matched for body weight and fasting serum TG concentration. Postprandial lipemia was lower in athletes after meals containing 40 g fat (1.5 +/- 0.7 vs 2.6 +/- 1.5 mmol.L-1.8 h-1, p less than 0.001) or 140 g fat (2.5 +/- 1.2 vs 6.1 +/- 1.9 mmol.L-1.8 h-1, p less than 0.001). The disappearance of an intravenous bolus of Intralipid was faster in athletes (5.4 +/- 1.2%/min) than in sedentary men (4.3 +/- 0.8%/min, p less than 0.01). The half-life of chylomicron-TG was shorter in athletes (3.0 +/- 0.8 min) than in sedentary men (4.0 +/- 1.0 min, p less than 0.05). These findings indicate that chronic exercise decreases postprandial lipemia by reducing chylomicron-TG's half-life. This effect is due partly to reduced fasting serum TG pool size and partly to a direct effect of exercise on the serum TG removal system.
authors.affiliation: Department of Physiology, University of Cape Town Medical School, Republic of South Africa.
authors.forename: J C
authors.initials: JC
authors.lastname: Cohen
authors.forename: T D
authors.initials: TD
authors.lastname: Noakes
authors.forename: A J
authors.initials: AJ
authors.lastname: Benade
mesh_terms: D000328:Adult; D002914:Chylomicrons / Q000097:blood*; D004435:Eating; D015444:Exercise; D006801:Humans; D008297:Male; D014280:Triglycerides / Q000097:blood*
chemical_list: D002914:Chylomicrons; D014280:Triglycerides