Effect of sport stress on lymphocyte transformation and antibody formation.

The effect of a heavy (marathon, 2.5 hr) and moderate (35 min of running) sport stress on the number and function of lymphocytes, and on the plasma cortisol and leucocyte levels was investigated. Marathon running had a profound effect on the lymphocytes. Though the total number of lymphocytes did not change, their responsiveness to PHA and Con A, especially to PPD, was clearly depressed. The suppression of lymphocyte transformation was transient, the recovery occurring in 24 hr. The marathon running had no effect on antibody-forming capacity when the antigen was given immediately after the performance of the marathon, i.e. at the time when the response of lymphocytes to PHA, Con A and PPD stimulation was impaired. A clear-cut granulocytosis and elevation of plasma cortisol was seen in all the marathon runners. The 35 min of running also resulted in granulocytosis and an increase of plasma cortisol, but it did not cause any impairment of the lymphocyte function.