Influence of carbohydrate ingestion on counterregulatory hormones during prolonged exercise

Gespeichert in:
Bibliographische Detailangaben
Deutscher übersetzter Titel:Einfluss von Kohlenhydratzufuhr auf die gegenregulatorischen Hormone waehrend Ausdauerbelastung
Autor:Mitchell, J.B.; Costill, D.L.; Houmard, J.A.; Flynn, M.G.; Fink, W.J.; Beltz, J.D.
Erschienen in:International journal of sports medicine
Veröffentlicht:11 (1990), 1, S. 33-36, Lit.
Format: Literatur (SPOLIT)
Publikationstyp: Zeitschriftenartikel
Medienart: Gedruckte Ressource Elektronische Ressource (online)
Sprache:Englisch
ISSN:0172-4622, 1439-3964
DOI:10.1055/s-2007-1024758
Schlagworte:
Online Zugang:
Erfassungsnummer:PU199005043467
Quelle:BISp

Abstract

This study was undertaken to determine the effects of ingesting 5.0 (CHO-5), 6.0 (CHO-6), and 7.5 g/100 ml (CHO-7.5) carbohydrate (CHO) solutions on blood glucose and counterregulatory hormonal responses during prolonged intermittent exercise. Eight well-trained cyclists performed four trials consisting of seven 12-min cycling bouts at 70 of VO2max with 3 min rest between each ride. A final 12 min ride was an all-out self-paced performance ride. During the rest interval the subjects ingested either a water placebo (WP) or one of the CHO solutions at a rate of 8.5 mg/kg/h (approx. 150 ml). Blood samples were taken at 0, 25, 55, 85, and 115 min of exercise and were assayed for glucose, glucagon (GG), cortisol (CT), insulin (IN), epinephrine (EP), and norepinephrine (NE). Blood glucose levels were significantly lower in the WP trial compared to the CHO trials at 25 (4.6 +/- 0.2 vs 5.7 +/- 0.5 mmol/l) and 55 min (4.4 +/- 0.3 vs 5.0 +/- 0.8 mmol/l). At 85 min blood glucose was significantly lower in the WP compared to the CHO-6 and CHO-7.5 trials. GG and IN levels were not significantly different between trials; however, the GG:IN molar ratio was significantly higher in the WP than in the CHO-7.5 trial. CT was significantly elevated in the WP trial compared to the CHO-7.5 trial. EP and NE levels were not affected by CHO ingestion. These data suggest that CHO feedings prevent the typical hormonal responses which are responsible for hepatic glucose release, thus eliciting a possible hepatic glycogen sparing. Verf.-Referat