Effect of exercise intensity on active and passive glucose absorption.
The purpose of this study was to determine the effects of exercise intensity on active and passive intestinal glucose absorption. Eight trained runners (age = 23 +/- 2 y; VO2max = 62.1 +/- 5.8 mL x kg(-1) x min(-1)) performed a 1 h resting experiment and three 1 h treadmill experiments at 30, 50, or 70% VO2max in a thermoneutral environment. Immediately prior to each experiment, euhydrated subjects ingested a solution containing two non-metabolizable glucose analogs, 3-O-methyl-D-glucose (3MG; actively absorbed; 5 g) and D-xylose (passively absorbed; 5 g). During the following 5 h, all urine was collected and the amount of 3MG and D-xylose in the urine was determined. Using repeated measures ANOVA, a significant (P < 0.05) reduction in urinary excretion of each carbohydrate was observed at 70% VO2max compared to the other intensities suggesting that both active and passive intestinal absorption of glucose may be reduced during prolonged running at this intensity.
Lang
James A
JA
Dept of Exercise Science and Athletic Training, Creighton University, Omaha, NE 68178, USA.
Gisolfi
Carl V
CV
Lambert
G Patrick
GP
D000328:Adult; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000493:pharmacokinetics* / Q000652:urine; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005947:Glucose / Q000378:metabolism / Q000493:pharmacokinetics*; D006029:Glycosuria; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D010101:Oxygen Consumption; D012420:Running
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005947:Glucose