title: Effect of preexercise ingestion of modified cornstarch on substrate oxidation during endurance exercise.
abstract: The purpose of this study was to investigate differences in substrate oxidation between dextrose (DEX) and unmodified (UAMS) and acid/alcohol-modified (MAMS) cornstarches. Seven endurance-trained men (VO2peak = 59.1 +/- 5.4 mL.kg-1.min-1) participated in 2 h of exercise (66.4% +/- 3.3% VO2peak) 30 min after ingesting 1 g/kg body weight of the experimental carbohydrate or placebo (PLA). Plasma glucose and insulin were elevated after DEX (P < 0.05) compared with UAMS, MAMS, and PLA. Although MAMS and DEX raised carbohydrate oxidation rate through 90 min of exercise, only MAMS persisted throughout 120 min (P < 0.05 compared with all trials). Exogenous-carbohydrate oxidation rate was higher in DEX than in MAMS and UAMS until 90 min of exercise. Acid/alcohol modification resulted in augmented carbohydrate oxidation with a small, sustained increase in exogenous-carbohydrate oxidation rate. MAMS appears to be metabolizable and available for oxidation during exercise.
authors: Health and Human Performance, Iowa State University, Ames, IA 50014, USA.
authors: Neil M
authors: NM
authors: Johannsen
authors: Rick L
authors: RL
authors: Sharp
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D001944:Breath Tests; D050260:Carbohydrate Metabolism / Q000187:drug effects*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism*; D004311:Double-Blind Method; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects / Q000502:physiology*; D013213:Starch / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D013213:Starch; D005947:Glucose