Effects of a single incremental exhausting exercise on circulting numbers of lymplocyes subsets in male athletes

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 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.