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Introduction: Physical activity, despite an increased production of free radicals due to stress oxidation, reduces production of free radicals due to product antioxidant enzymes. The aim of this study was to investigate the acute effects of eccentric and concentric exercise on oxidant and antioxidant factors in active young women. Materials & Methods: Twenty four voluntary female students participated in the study, who were randomly assigned to three groups: control (no training), eccentric training group (ellestad test with reverse slope), and concentric training group (ellestad test with straight slope). Blood samples were collected 1h before and immediately after exercise for assessment of plasma total antioxidant capacity (TAC), glutathione (GSH), and malondialdehyde (MDA). The SPSS software Ver.13 was used, while one-way variance was applied to determine dependent variables. T-test analysis was performed on values from blood samples to obtain differences between pre-and post training values. Findings: The results showed that after eccentric and concentric exercise, there were a significant increase in plasma TAC, GSH, MDA levels compared with that of what before the exercise, (p<0.05). However, there was no significant increase in TAC concentric training group. Discussion & Conclusion: In conclusion, we suggest that eccentric and concentric exercise may improve antioxidant levels and the defenses of athletic bodies in facing with free radicals.