IMMUNOLOGICAL STATUS OF COMPETITIVE CYCLISTS BEFORE AND AFTER THE TRAINING SEASON

The total number of leucocytes, T lymphocyte subsets, mitogen induced proliferation of lymphocytes, Il-2 generation, adherence capacity and chemiluminescence of granulocytes were measured and a leukergy test pe rformed in fifteen young cyclists. The investigations were carried out at rest at the beginning of a training season and after six months of intensive training and a racing season, cycling approximately 500 km a week. Baseline values of the tested immune parameters were within th e range observed in 16 non-trained healthy controls except significant ly increased non stimulated neutrophil chemiluminescence. The second c yclo-ergometer test in August showed a marked improvement in the perfo rmance capacity of the cyclists. Significant decrease in absolute numb ers of CD3(+) and CD4(+) cells, diminished IL-2 generation and fMLP an d PMA stimulated chemiluminescence of neutrophils were noted. Surprisi ngly, a marked increase in lymphocyte proliferation induced by PHA and anti-CD3 MoAb and normalisation in non stimulated neutrophil chemilum inescence were also observed at rest after the training season. We con clude that long-lasting intensive training may result in significant a lterations in lymphocyte number and composition and in neutrophil oxid ative burst capacity, but their actual significance for immunity is se en controversially.