Concurrent exercises (endurance & resistance) have been utilized in many sports. This study aimed at investigating the effect of concurrent exercise of endurance- resistance versus resistance-endurance on cell damage serum indices (CK, CKMB, CKMM, and LDH) and Testosterone /Cortisol ratio in non-athlete males. Sixteen healthy males in two groups of endurance-resistance group (E-R) and resistance - endurance group (R-E) participated in this study. Blood samples were taken 5 minutes before and one hour after the exercise protocols. The plasma was examined for CK, CKMB, CKMM, LDH, cortisol and testosterone. At the beginning, normality of the collected data was approved through Kolmogorov-Smirnov test and then the data was analyzed by paired and independent samples t test at p≤ 0.05. The findings indicated significant changes of all indices before and after the exercise protocols in both groups (except for the testosterone change before and after the exercise in group one, together with cortisol change and the ratio of testosterone to cortisol in both groups). However, there was no significant difference between the groups as far as the mentioned indices were concerned. The results revealed that both exercise protocols caused increase and decrease in some cell damage serum indices, though the percentage of rise and fall of these indices (CK, CKMB, CKMM, and LDH vs. high cortisol; testosterone and testosterone ratio to low cortisol) before and after the exercise protocols was higher in group two (endurance- resistance) compared with group one (resistance-endurance).
