Effect of ß-adrenoceptor blockade on post-exercise oxygen consumption and triglyceride/fatty acid cycling

In the recovery period after strenuous exercise there is an increased O2 uptake termed the excess post-exercise O2 consumption (EPOC). One mechanis suggested to explain EPOC is activation of the triglyceride /fatty acid (TG/FA) cycle by catecholamines. The purpose of this stud y was to determine the effect of selective ß1- and non-selective ß-bl ockade on EPOC and TG/FA cycling. Seven healthy men each participated in three rest and three exercise experiments. In the exercise experi ments they exercised for 90 min at 58 ± 2% (mean ± SD) of VO2 max on a cycle ergometer followed by 4.5 h bedrest. The rest experiments fol lowed the same protocol, but without exercise. In one rest and one ex ercise experiment the selective ß1-antagonist atenolol (0.062 mg•kg-1 bw) was administered i.v. immediately after the exercise, and at cor responding time in the rest experiment. In a second set of rest and e xercise experiments the non-selective ß-antagonist propranolol (0.15 mg•kg-1 bw) was administered. In a third set of rest and exercise exp eriments an injection of saline was given instead of ß-antagonist. TG /FA cycling was calculated by combining results obtained with glycero l infusion and indirect cal