TOLERANCE TO INTENSIVE EXERCISE AND HIGH-LEVELS OF LACTATE IN PANIC DISORDER

We wanted to test the tolerance of intensive exercise and correspondin g high levels of lactate in patients with panic disorder. Thirty-five consecutive patients with DSM-III-R panic disorder completed submaxima l tests, and 24 completed additional supramaximal exercise tests. All experienced high values of lactate during the supramaximal test (M = 1 0.7 mmol/L, SD = 2.9), but only 1 patient experienced a panic attack. The blood lactate values in the present study were higher than the usu ally achieved values of 5 to 6 mmol/L during infusion. In general, 67% of patients-panic during infusion, compared to 4% in the present stud y. This discrepancy in frequency of panic following exposure to endoge nous and exogenous lactate is discussed on the basis of various hypoth eses of panic disorder, with an emphasis on cognitive theory of panic. The study indicates that patients with panic disorder can safely unde rgo vigorous exercise of such intensity to result in significant lacta te production, with the chances of panic being small. (C) 1998 Elsevie r Science Ltd.