RESPONSES OF LYMPHOCYTE SUBSETS, MITOGEN-STIMULATED CELL PROLIFERATION, AND IMMUNOGLOBULIN SYNTHESIS TO VIGOROUS EXERCISE IN WELL-TRAINED ATHLETES

Abstract

Lymphocyte subsets, mitogen-stimulated cell proliferation rates, and immunoglobulin levels were evaluated before and following 30 min of treadmill exercise at 80% of directly measured maximal oxygen intake. The subjects were 10 well-trained male runners (age 29.8 ± 1.7 years, maximal oxygen intake 65.3 ± 4.9 ml kg−1 min−1, 10 km times 32:17 ± 1:38 min). The treadmill session induced a 20% increment of plasma cortisol 5 min following exercise, with restoration of normal values 30 min postexercise. High initial plasma creatine kinase levels showed a small increase 5 min postexercise, with a trend to a further increment 30 min postexercise. The percentages of T-lymphocytes and B-lymphocytes in peripheral venous blood were unchanged by exercise, but there was a decrease in the percentage of helper cells 5 min postexercise, with a trend to a small and transient decrease in the helper cell/suppressor cell ratio. The exercise session had no influence upon the proliferative response of peripheral blood mononuclear cells to mitogens, but there was a significant increase of pokeweed mitogen-stimulated IgG synthesis 5 min postexercise, with an incomplete return to normal values at 30 min. It may be concluded that 30 min of treadmill exercise comparable with a normal training run induces no more than transient changes of immune parameters in the well-trained distance runner.