Abstract

Circulatory leukocytes vary significantly in response to acute bouts of exercise. However, little is known concerning the adaptability of this response to chronic intense exercise training. We investigated the circulating leukocytic response to acute exercise in trained athletes during a 28-d intense exercise training program. On day 0, 14, 28 and two days after cessation of the increased training, 8 trained male athletes were subjected to a 20-km bicycle ergometer time trial. Blood samples were drawn before (PRE, resting baseline values) and 5 min after (POST, response to acute exercise) the time trial. Beginning on day 0, athletes were instructed to increase the duration of their training 50. The intense exercise training, which lasted 28 days, was verified weekly. Acute bouts of exercise caused a significant increase in circulating white blood cells, lymphocytes, polymorphonuclear neutrophils and monocytes. The baseline resting values and the magnitude of the response to the acute bouts of exercise in the above parameters were not different during the 28 days of chronic intense exercise training or 2 d after cessation of training as compared to the values observed on day O. Similarly there was a significant increase in cortisol in response to the acute bouts of exercise during the chronic intense exercise training, but the increase was not different from that observed under baseline conditions. Results indicate that chronic intense exercise training does not alter the circulating leukocytic response to acute exercise. Verf.-Ref.