The adaptive potential of human immunity during strength training

Quantitative and functional characteristics of human T-and B-cell-related immunity and natural cytotoxicity were studied during nine-week strength training. Long-term classic strength training and low-intensity strength training without relaxation did not change the peripheral blood contents of the main subpopulations of immunocompetent cells, the phytohemagglutinin-induced proliferative activity of T lymphocytes, serum levels of immunoglobulins A, M, and G (IgA, IgM, and IgG, respectively) and the cytotoxic activity of natural killer cells. At the same time, training was accompanied by activation of the immune system, which was evident from increased counts of CD25⁺ lymphocytes observed in the peripheral blood and in the mitogen-stimulated and nonstimulated cell cultures, as well as from the higher spontaneous and mitogen-induced productions of IgA, IgM, and IgG by B lymphocytes.