ABSTRACT
Intense exercise activity has been known as one of the immune system suppressor. The purpose of the present study was to examine the effect of a single incremental exhausting exercise on circulting numbers of T cell and NK cell subsets in healthy young male athletes. Twenty male subjects with mean age 22/4 +/- 1/8 [SD] yr, mean Vo2max 41/7 +/- 7/1 [SD] ml/kg/min and mean BMI 23 +/- 1/87 [SD] kg/m2 were divided randomly into two control group [n=10] and experimental group [n=10]. The experimental subjects performed a standard bicycle ergometer test whereas the control subjects did not participate in any exercise activity. Blood samples were collected pre-, immediately post-, and 2 hours post-exercise. The T and and NK lymphocyte subsets were analyzed with flow cytometry. There was a significant increase in the percentage of T [CD8] and NK [CD16/56] and a significant decrase in the percentage of T [CD4] and the ratio of CD4/CD8 from pre-, to immediately post-exercise [p<0.05]. Both changes returned to pre-exercise values at 2 hours post-exercise. Addtionally, no significant changes was found in the percentage of CD56 and CD16 [NK] cells following exercise Findings of this study indicate a single intense and short-term training session caused transient and temporary changes in circulating lymphocytes counts. Thus, it is reommonded that the interval between training designed in a way that the immune system reverts back to its original status