Carbohydrate ingestion can completely suppress endogenous glucose production during exercise.
Am J Physiol
; 276(4): E672-83, 1999 04.
Article
em En
| MEDLINE
| ID: mdl-10198303
ABSTRACT
The purposes of this study were 1) to investigate the effect of carbohydrate (CHO) ingestion on endogenous glucose production (EGP) during prolonged exercise, 2) to study whether glucose appearance in the circulation could be a limiting factor for exogenous CHO oxidation, and 3) to investigate whether large CHO feedings can reduce muscle glycogen oxidation during exercise. Six well-trained subjects exercised three times for 120 min at 50% maximum workload while ingesting water (FAST), a 4% glucose solution (LO-Glc), or a 22% glucose solution (HI-Glc). A primed continuous intravenous [6, 6-2H2]glucose infusion was given, and the ingested glucose was enriched with [U-13C]glucose. Glucose ingestion significantly elevated CHO oxidation as well as the rates of appearance (Ra) and disappearance. Ra glucose equaled Ra of glucose in gut (Ra gut) during HI-Glc, whereas EGP was completely suppressed. During LO-Glc, EGP was partially suppressed, whereas Ra gut provided most of the total glucose Ra. We conclude that 1) high rates of CHO ingestion can completely block EGP, 2) Ra gut may be a limiting factor for exogenous CHO oxidation, and 3) muscle glycogen oxidation was not reduced by large glucose feedings.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carboidratos da Dieta
/
Exercício Físico
/
Músculo Esquelético
/
Esforço Físico
/
Glucose
/
Glicogênio
Tipo de estudo:
Prognostic_studies
Limite:
Adult
/
Humans
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Holanda