The aim of this study was to compare changes in serum levels of IL-2, IL-6, TNFα, IFN-γ and CRP in athletes of speed runners and non-athletes. The statistical sample of this study included 70 young men aged 20 to 25 years old. Twenty participants were spirnter and 50 non-athletes. Then, they were divided into two groups: speed runners (20 persons) with mean (78 ± 41.4 kg; height: 181.2 ± 13.2 cm; age: 21.2 ± 14 years; body mass index: 1.94 ± 1; 23) and non-athletic group (50 persons) with mean (weight: 77 ± 6.26 kg; height: 180 ± 3,22 cm; 22 ± 2/45; body mass index 23 ± 2/02). Blood samples were prepared to measure the IL-2, IL-6, TNFα, IFN-γ and CRP variables and were determined by ELISA method. In order to analyze the data, inferential statistical test of independent t test was used for comparison between groups. Independent t-test showed a significant difference between the groups in IL-2 (p = 0.0225, IL-6 (p = 0.028), TNFα (p = 0.1010) and CRP (p= 0.016); however, there was no significant difference in the level of IFN-γ between the two groups. Considering that cytokine changes were observed in speed runners. It is recommended that the trainers make a significant contribution to strengthening the safety system during the preparation period.
