Glucoregulatory responses to intense exercise performed in the postprandial state

Stuart H. Kreisman, Anthony Manzon, Sharon J. Nessim, José A. Morais, Réjeanne Gougeon, Simon J. Fisher, Mladen Vranic, Errol B. Marliss

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

A seven- to eightfold increment in hepatic glucose production (endogenous R(a)) occurs in postabsorptive (PA) intense exercise (IE). A similar response is likely present in the postprandial (PP) state, when most such exercise is performed, because 1) little evidence for increased intestinal absorption of glucose during exercise exists, and 2) intravenous glucose does not prevent it. We investigated IE in 10 PA and 8 PP fit, lean, young males who had exercised for 15 min at >84% maximum O2 uptake, starting 3 h after a 412-kcal mixed meal. The meal induced a small rise in glycemia with sustained insulin and glucagon increases. Preexercise glucose total R(a) and utilization (R(a)) were equal and ~130% of the PA level. Exercise hyperglycemia in PP was delayed and diminished and, in early recovery, was of shorter duration and lesser magnitude (P = 0.042). Peak catecholamine (12- to 16-fold increase) and R(a) (PP: 11.5 ± 1.4, PA: 13.8 ± 1.4 mg·kg- 1·min-1) responses did not differ, and their responses during exercise were significantly correlated. Exercise glucagon, insulin, and glucagon-to- insulin responses were small or not significant. R(d) reached the same peak (PP: 8.0 ± 0.6, PA: 9.3 ± 0.8 mg·kg-1·min-1) but was greater at 20- 120 min of recovery in PP (P = 0.001). Therefore, the total R(a) response to IE is preserved despite the possibility of prior PP suppression of endogenous R(a) and is consistent with catecholamine mediation. Post-IE hyperglycemia is reduced in the postprandial state.

Original languageEnglish
Pages (from-to)E786-E793
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume278
Issue number5 41-5
DOIs
StatePublished - May 2000

Keywords

  • Catecholamines
  • Glucagon
  • Glucose turnover
  • Insulin
  • Postprandial exercise

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Physiology (medical)

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