PERFORMANCE AND METABOLIC EFFECTS OF BENZODIAZEPINE DURING SUBMAXIMALEXERCISE

The present study examined whether benzodiazepine (BZ) intake alters p erformance and selected hormonal and metabolic variables during submax imal exercise. Seven triathletes completed two cycling trials at 85% m aximum O-2 uptake starting 3h after an ingestion of either a placebo ( PLA) of gelatin or BZ (1.5 mg lorazepam) and continuing until exhausti on, according to a double-blind randomized protocol. Blood samples wer e collected at rest; 5, 10, and 15 min; and exhaustion for dopamine (D A), norepinephrine (NE), epinephrine (Epi), adrenocorticotropic hormon e (ACTH), cortisol (CORT), insulin (INS), free fatty acid, blood gluco se, and lactate (La) determinations. Time of cycling was not significa ntly changed after BZ or PLA administration (22.9 +/- 2.5 vs. 23.5 +/- 3.8 min, respectively). A decrease in CORT and an increase in INS (P < 0.05) were observed with BZ before cycling. In comparison with rest, exercise resulted in a decrease in INS and an increase in all the oth er variables investigated (P < 0.001), but DA, NE, Epi, ACTH, CORT, La , and free fatty acid were significantly less elevated under BZ (P < 0 .05). No change was found in glucose and INS levels between the two tr eatments at the end of the test. There was a strong correlation under both PLA and BZ conditions between DA, NE, Epi, and ACTH and also betw een Epi and La levels. From these data, BZ intake did appear to alter metabolism but did not influence performance during intense submaximal exercise.