title: Fructose and Sucrose Intake Increase Exogenous  Carbohydrate Oxidation during Exercise.
abstract: Peak exogenous carbohydrate oxidation rates typically reach ~1 g∙min-1 during exercise when ample glucose or glucose polymers are ingested. Fructose co-ingestion has been shown to further increase exogenous carbohydrate oxidation rates. The purpose of this study was to assess the impact of fructose co-ingestion provided either as a monosaccharide or as part of the disaccharide sucrose on exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. Ten trained male cyclists (VO2peak: 65 ± 2 mL∙kg-1∙min-1) cycled on four different occasions for 180 min at 50% Wmax during which they consumed a carbohydrate solution providing 1.8 g∙min-1 of glucose (GLU), 1.2 g∙min-1 glucose + 0.6 g∙min-1 fructose (GLU + FRU), 0.6 g∙min-1 glucose + 1.2 g∙min-1 sucrose (GLU + SUC), or water (WAT). Peak exogenous carbohydrate oxidation rates did not differ between GLU + FRU and GLU + SUC (1.40 ± 0.06 vs. 1.29 ± 0.07 g∙min-1, respectively, p = 0.999), but were 46% ± 8% higher when compared to GLU (0.96 ± 0.06 g∙min-1: p < 0.05). In line, exogenous carbohydrate oxidation rates during the latter 120 min of exercise were 46% ± 8% higher in GLU + FRU or GLU + SUC compared with GLU (1.19 ± 0.12, 1.13 ± 0.21, and 0.82 ± 0.16 g∙min-1, respectively, p < 0.05). We conclude that fructose co-ingestion (0.6 g∙min-1) with glucose (1.2 g∙min-1) provided either as a monosaccharide or as sucrose strongly increases exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists.
authors.affiliation: NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, P.O. Box 616, 6200 MD Maastricht, The Netherlands. jorn.trommelen@maastrichtuniversity.com.
authors.forename: Jorn
authors.initials: J
authors.lastname: Trommelen
authors.affiliation: NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, P.O. Box 616, 6200 MD Maastricht, The Netherlands. cas.fuchs@maastrichtuniversity.nl.
authors.forename: Cas J
authors.initials: CJ
authors.lastname: Fuchs
authors.affiliation: NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, P.O. Box 616, 6200 MD Maastricht, The Netherlands. milou.beelen@maastrichtuniversity.nl.
authors.forename: Milou
authors.initials: M
authors.lastname: Beelen
authors.affiliation: NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, P.O. Box 616, 6200 MD Maastricht, The Netherlands. kaatje.lenaerts@maastrichtuniversity.nl.
authors.forename: Kaatje
authors.initials: K
authors.lastname: Lenaerts
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough LE11 3TU, UK. asker@mysportscience.com.
authors.forename: Asker E
authors.initials: AE
authors.lastname: Jeukendrup
authors.affiliation: NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, P.O. Box 616, 6200 MD Maastricht, The Netherlands. naomi.cermak1234@gmail.com.
authors.forename: Naomi M
authors.initials: NM
authors.lastname: Cermak
authors.affiliation: NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, P.O. Box 616, 6200 MD Maastricht, The Netherlands. l.vanloon@maastrichtuniversity.com.
authors.forename: Luc J C
authors.initials: LJ
authors.lastname: van Loon
mesh_terms: D000328:Adult; D001642:Bicycling; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight; D018592:Cross-Over Studies; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism*; D004311:Double-Blind Method; D015444:Exercise; D005632:Fructose / Q000008:administration & dosage*; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D007328:Insulin; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D013395:Sucrose / Q000008:administration & dosage*
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D005632:Fructose; D019344:Lactic Acid; D013395:Sucrose; D005947:Glucose
keywords: substrate utilization;  metabolism;  stable isotopes;  sugar