Effects of exercise at different times on postprandial lipemia and endothelial function.
OBJECTIVE
The purpose of this study was to examine the effects of previous exercise on metabolic, hormonal, and endothelial responses to an oral fat-tolerance test (OFTT).


METHODS
Twelve healthy, recreationally trained men (age = 22.3 +/- 2.5 yr, weight = 80.7 +/- 12.4 kg, BMI = 25.1 +/- 3.1 kg.m(-2)) volunteered for this study. In a crossover fashion, subjects completed three OFTT trials that involved no exercise (NoEx) or exercise performed 16 h (EX-16) or 4 h (EX-4) before the ingestion of a meal (13 kcal.kg(-1) and 1.4 g of fat per kilogram of body weight). Blood was collected before and after the meal and hourly for 6 h. Brachial artery reactivity was measured using ultrasound before and at 2, 4, and 6 h after the meal. Dietary intake and exercise were standardized 4 d before the OFTT. The exercise session consisted of six resistance exercises and 30 min of running on a treadmill. The washout period between trials was, on average, 5 d.


RESULTS
Compared with NoEx, there were significant (P < 0.05) decreases in triglyceride area under the curve (AUC) during EX-16 (-26%) and EX-4 (-15%). Compared with NoEx, there were decreases in insulin AUC during EX-16 (-7%, P < 0.05) and EX-4 (-5%, NS). EX-4 resulted in a significantly larger fasting arterial diameter than EX-16 and NoEx, but there were no other significant effects on endothelial function. Lipemic variables did not show correlations with endothelium function for any of the trials.


CONCLUSIONS
An acute exercise session, regardless of the time point chosen (i.e., EX-16 or EX-4), reduced to a similar extent the total and incremental lipemic responses compared with the NoEx condition.
Silvestre
Ricardo
R
Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA.
Kraemer
William J
WJ
Quann
Erin E
EE
Seip
Richard L
RL
Maresh
Carl M
CM
Vingren
Jakob L
JL
Hatfield
Disa L
DL
Volek
Jeff S
JS
D000284:Administration, Oral; D000328:Adult; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D002318:Cardiovascular Diseases / Q000517:prevention & control; D003237:Connecticut; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000008:administration & dosage; D004727:Endothelium / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000378:metabolism*; D008297:Male; D019518:Postprandial Period / Q000502:physiology*; D013997:Time Factors; D014463:Ultrasonography
D004041:Dietary Fats