Adrenergic control of post-exercise metabolism

After strenuous exercise there is a sustained increase in resting O2 consumption. The magnitude and duration of the excess post-exercise O 2 consumption (EPOC) is a function of exercise intensity and exercise duration. Some of the mechanisms underlying the rapid EPOC component (<1 h) are well defined, while the mechanisms causing the prolonged EPOC component (>1 h) are not fully understood. It has been suggested that ß-adrenergic stimulation is of importance for the prolonged com ponent. There is an increased level of plasma adrenaline and noradren aline during exercise, and it is shown that catecholamines stimulate energy expenditure through ß-adrenoceptors. After exercise an increas ed fat oxidation and an increased rate of triglyceride-fatty acid cyc ling may account for a significant part of the prolonged EPOC compone nt. These processes may be stimulated by catecholamines. However, th e return of plasma concentration of catecholamines to resting level a fter exercise are more rapid than the return of O2 uptake. But plasma concentration of catecholamines may be an insensitive indicator of s ympathetic activity, since the clearance rate of catecholamines is hi gh. Also, the sensitivity t