CELLULAR AND HUMORAL IMMUNE-RESPONSE TO EXERCISE AMONG GYMNASTS AND UNTRAINED GIRLS

Recent studies reported reduced immunity in athletes following exercis e. Physical activity affects both cellular and humoral immune function s. Scant information exists on exercise-induced changes in the immune system among children. The purpose of the present study was to investi gate the effect of aerobic exercise on several aspects of cellular and humoral functions among 10-12 year-old highly trained female gymnasts (n = 7) and untrained girls (n = 6). All girls were pre-pubertal. Ven ous blood samples were drawn before, immediately after and 24 h follow ing 20 min of treadmill running (heart rate 170-180 beats.min(-1)). Wh ite blood cells' number rose significantly following exercise and rema ined elevated for 24 h. The increase in leukocyte number was due to an increase in granulocytes as well as an increase in lymphocytes and mo nocytes. While neutrophil count returned to basal values after 24 h, l ymphocytes and monocytes number remained elevated 24 h following exerc ise. Exercise resulted in a significant elevation of T cell lymphocyte s, T helpers, T suppressors and natural killer cells. All values retur ned to normal after 24 h. There were no changes in B cell lymphocytes following exercise. Exercise had no effect on serum IgA, IgM, IgE, IgG and sub-types of IgG (IgG(1), IgG(2), IgG(3) and IgG(4)). No differen ces were observed between gymnasts and untrained girls. In summary, th e exercise-induced changes in cellular and humoral immune functions am ong the girls were generally similar to those described in adults. Whe ther the transitory effects of exercise on the immune system are relat ed to increased susceptibility to illness is still questionable.