CD8A and viral infectious disease: Although the variations of the immune cells observed along the training season kept the numbers within the clinically normal reference range, not anticipating or suggesting an impairment of the immune defenses or an increased susceptibility to viral infections, and we did not evaluate any functional parameter of these cells that may suggest increased or decreased immune competence, in our study the decreases in eosinophils, and CD16+56+ and CD8+ subsets were concomitant with the increase of the number of URS (M3).