title: Gastric emptying and intestinal absorption of a low-carbohydrate sport drink during exercise.
abstract: The purpose of this study was to determine if lowering carbohydrate (CHO) concentration in a sport drink influences gastric emptying, intestinal absorption, or performance during cycle ergometry (85 min, 60% VO(2peak)). Five subjects (25 +/- 1 y, 61.5 +/- 2.1 mL . kg(-1) . min(-1) VO(2peak)) ingested a 3% CHO, 6% CHO, or a water placebo (WP) beverage during exercise. Gastric emptying was determined by repeated double sampling and intestinal absorption by segmental perfusion. Total solute absorption and plasma glucose was greater for 6% CHO; however, neither gastric emptying, intestinal water absorption, or 3-mi time trial performance (7:58 +/- 0:33 min, 8:13 +/- 0:25 min, and 8:25 +/- 0:29 min, respectively, for 6% CHO, 3% CHO, and WP) differed among solutions. These results indicate lowering the CHO concentration of a sport drink from 6% CHO does not enhance gastric emptying, intestinal water absorption, or time trial performance, but reduces CHO and total solute absorption.
authors.affiliation: Department of Exercise Sciences, the University of Iowa, Iowa City, IA 68178, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rogers
authors.forename: Robert W
authors.initials: RW
authors.lastname: Summers
authors.forename: G Patrick
authors.initials: GP
authors.lastname: Lambert
mesh_terms: D000328:Adult; D001628:Beverages; D001642:Bicycling / Q000502:physiology*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D004326:Drinking; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology*; D008297:Male; D010101:Oxygen Consumption
chemical_list: D004040:Dietary Carbohydrates