Exogenous CHO Oxidation with Glucose Plus Fructose Intake during Exercise

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Authors

Colleges, School and Institutes

Abstract

HULSTON, C. J., G. A. WALLIS, and A. E. JEUKENDRUP. Exogenous CHO Oxidation with Glucose Plus Fructose Intake during Exercise. Med. Sci. Sports Exerc., Vol. 4 1, No. 2, pp. 357-363, 2009. Purpose: The purpose of the present study was to determine whether combined ingestion of moderate amounts Of glucose Plus fructose would result in higher rates of exogenous CHO oxidation compared with an isocaloric amount of glucose alone. Methods: Seven endurance-trained male cyclists performed three experimental trials consisting of 150 min of cycling at 65% VO2max. Subjects ingested a CHO solution providing glucose (GLU) at an average rate of 0.8 g.min(-1), glucose (0.54 g.min(-1)) plus fructose (0.26 g.min(-1)) (GLU + FRU), or plain water (WAT) during exercise. To quantify exogenous CHO oxidation, we prepared CHO solutions using corn-derived GLU and FRU, with a high natural abundance of C-13 Results: Peak exogenous CHO oxidation rates were not significantly different between GLU and GLU + FRU (0.60 +/- 0.06 and 0.57 +/- 0.06 g.min(-1), respectively). Furthermore, average exogenous CHO oxidation rates during the final 90 min of exercise were not significantly different between GLU and GLU + FRU (0.58 +/- 0.05 and 0.56 +/- 0.06 g.min(-1), respectively). Conclusion: The present study demonstrates that ingesting moderate amounts of glucose plus fructose does not increase exogenous CHO oxidation above that of an isocaloric amount of glucose alone.

Details

Original languageEnglish
Pages (from-to)357-363
Number of pages7
JournalMedicine and Science in Sports and Exercise
Volume41
Issue number2
Publication statusPublished - 1 Jan 2009

Keywords

  • SUBSTRATE UTILIZATION, STABLE ISOTOPES, CYCLING EXERCISE, CHO ABSORPTION