Gastric emptying, absorption, and carbohydrate oxidation during prolonged exercise

• DOI: 10.1152/jappl.1992.72.2.468
• Publication Date: 2017-12-21T23:39:06Z
• Authors: N. J. Rehrer; A. J. Wagenmakers; E. J. Beckers; D. Halliday; J. B. Leiper; F. Brouns; R. J. Maughan; K. Westerterp; W. H. Saris
• Keywords: Crossover study; Maltodextrin

This study was designed to examine aspects of digestive function that may limit assimilation water and oxidation orally ingested carbohydrate (CHO) during exercise. Eight males completed a crossover in which each cycled on four occasions for 80 min at 70% maximal O2 consumption. Beverage consumed 0, 20, 40, 60 min. Beverages were water, 4.5% glucose (4.5G), 17% (17G), maltodextrin (17MD). CHO beverages contained 20 meq/l NaCl 13C enriched measure exogenous oxidation. Gastric (beverage) volume measured Water uptake estimated by including 2H2O the beverage measuring 2H accumulation blood. Jejunal perfusion tests conducted rest with same subjects beverages. In min, 1,294 +/- 31 (SE) ml ingested; volumes emptied H2O (1,257 32 ml) 4.5G (1,223 greater than 17G (781 56 17MD (864 71 ml; P less 0.05). Total oxidized similar all beverages, but there increase over time 4.5G; 54, 19, 18% 4.5G, 17G, 17MD, respectively, oxidized. represents 57, 32, 27%, from stomach. blood more rapid or 17MD. Net jejunal absorption water. also observed whereas net secretion 17G.(ABSTRACT TRUNCATED AT 250 WORDS)