influence of selected exercise on serum immunoglobulin, testosterone and cortisol in semi-endurance elite runners

purpose the aim of this study was to compare the levels of serum immunoglobulin (iga, igm, igg), testosterone and cortisol in semi-endurance elite runners during general preparation and competition phase of training. methods thirteen semi-endurance elite male runners with an average age of 18.92±1.7 years volunteered to take part in this study. the runners participated in the selected training for a period of 14 weeks and 12 sessions per week (in the morning and afternoon). blood samples were collected during the three phases of training (before-preparation phase, after-preparation phase and before-competition phase). data were analyzed by repeated measures and bonferroni post hoc test, at a significance level of p<0.05. results the levels of serum igm in semi-endurance elite runners after preparation phase reduced significantly (p=0.004), while these levels during the competition phase increased even though significantly. the levels of serum igg and iga also reduced, however not significantly, during both phases. moreover, after preparation phase, there was no significant change in serum iga levels; though, these levels reduced, however not significantly, before competition phase. cortisol levels significantly decrease after preparation phase (p=0.04); although, it increased before competition phase. testosterone/cortisol ratio increases significantly after preparation phase (p=0.04), and it decreased before competition phase. testosterone levels intangibility increased and decreased respectively after preparation and before competition phases. conclusions findings indicated that long and intensive exercises weaken the immune system, while moderate and short drills strengthened this system.