Background: Catecholamines play an important role in many vital body functions such as the metabolism of carbohydrates and lipids. This research was designed to examine the changes in catecholamines during an intense and exhausting aerobic exercise.

Materials and Methods: In this study, fourteen healthy young men were taken a Bruce treadmill test with a mean time of 16.05 minutes and were totally exhausted. The blood samples of the participants were taken in four stages: before and after performing Bruce test and at third and fourth stages, one and two days immediately following the completion of test, respectively. The serum epinephrine and norepinephrine levels were analyzed using repeated measures ANOVA.

Results: Results showed that an intense and exhausting aerobic exercise significantly increased epinephrine (P>0.001) and norepinephrine (P>0.01) levels. Moreover, the norepinephrine level continued to increase two days after the aerobic exercise.

Conclusion: It seems that catecholamines respond differently to the same exercise. The changes observed probably depend on the pre-exercise athlete condition as well as the intensity and duration of activity. Moreover, a mean time of 16.05 minutes for the performance of an intense physical activity with maximum oxygen consumption (54.83 ml/kg/min) can cause considerable changes in research variables.