Glycemic and insulinemic responses to multiple preexercise carbohydrate feedings

Kevin R. Short, Melinda Sheffield-Moore, David L. Costill

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

This investigation was undertaken to determine whether consuming several small feedings of preexercise carbohydrate (CHO), rather than a single bolus, would affect blood glucose and insulin responses during rest and exercise. Eight trained cyclists ingested 22.5,45, or 75 total g maltodextrin and dextrose dissolved in 473 ml of water or an equal volume of placebo (PL). Drinks were divided into four portions and consumed at 15-min intervals in the hour before a 120-min ride at 66% V̇O2max. Serum glucose values were elevated by the CHO feedings at rest and fell significantly below baseline and PL at 15 min of exercise. However, glucose concentrations were similar in each of the CHO trials. Insulin concentrations also increased rapidly during rest, then fell sharply at the onset of exercise. The findings demonstrate that CHO consumed within an hour before exercise, even when taken in several small feedings, can produce transient hypoglycemia near the onset of exercise. Additionally, the magnitude of the response appears to be unrelated to either the amount of CHO ingested or the insulin response.

Original languageEnglish (US)
Pages (from-to)128-137
Number of pages10
JournalInternational Journal of Sport Nutrition and Exercise Metabolism
Volume7
Issue number2
DOIs
StatePublished - Jun 1997

Keywords

  • Carbohydrate oxidation
  • Diet
  • Glucose
  • Hypoglycemia

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Orthopedics and Sports Medicine
  • Nutrition and Dietetics

Fingerprint Dive into the research topics of 'Glycemic and insulinemic responses to multiple preexercise carbohydrate feedings'. Together they form a unique fingerprint.

  • Cite this