The dynamics of salivary hydrocortisone during exercise depends on the professional status of the athlete. Hydrocortisone concentrations increase and those of secretory IgA decrease significantly during short-term highly intense exercise. Presumably, basal serum hydrocortisone level is the key factor in restoration of the secretory IgA concentration after exercise by inhibition of lymphocyte, macrophage, and monocyte functions through an increase in glucocorticoid level under the effect of physiological stressors.