Effect of epinephrine on muscle glycogenolysis during exercise in trained men

M. A. Febbraio, D. L. Lambert, R. L. Starkie, J. Proietto, M. Hargreaves

Research output: Contribution to journalArticleResearchpeer-review

125 Citations (Scopus)


To test the hypothesis that an elevation in circulating epinephrine increases intramuscular glycogen utilization, six endurance-trained men performed two 40-min cycling trials at 71 ± 2% of peak oxygen uptake in 20- 22°C conditions. On the first occasion, subjects were infused with saline throughout exercise (Con). One week later, after determination of plasma epinephrine levels in Con, subjects performed the second trial (Epi) with an epinephrine infusion, which resulted in a twofold higher (P < 0.01) plasma epinephrine concentration in Epi compared with Con. Although oxygen uptake was not different when the two trials were compared, respiratory exchange ratio was higher throughout exercise in Epi compared with Con (0.93 ± 0.01 vs. 0.89 ± 0.01; P < 0.05). Muscle glycogen concentration was not different when the trials were compared preexercise, but the postexercise value was lower (P < 0.01) in Epi compared with Con. Thus net muscle glycogen utilization was greater during exercise with epinephrine infusion (224 ± 37 vs. 303 ± 30 mmol/kg for Con and Epi, respectively; P < 0.01). In addition, both muscle and plasma lactate and plasma glucose concentrations were higher (P < 0.05) in Epi compared with Con. These data indicate that intramuscular glycogen utilization, glycolysis, and carbohydrate oxidation are augmented by elevated epinephrine during submaximal exercise in trained men.

Original languageEnglish
Pages (from-to)465-470
Number of pages6
JournalJournal of Applied Physiology
Issue number2
Publication statusPublished - 1 Feb 1998
Externally publishedYes


  • Carbohydrate metabolism
  • Catecholamines
  • Training

Cite this