Effect of Different Caffeine Doses on Exercise-Induced Oxidative Stress in active Men

The aim of this study was to assess effect of different caffeine doses on exercise-induced oxidative stress (EIOS) measuring serum malondialdehyde (MDA) as lipid peroxidation indicator and GSH and vitamin E as markers of non-enzymatic antioxidant status. Ten male students of physical education participated in a double blind (5 or 9 mg·kg-1 body weight caffeine doses or placebo) treadmill test until exhaustion. Test was performed in separate 3 days and each subject was underwent one of caffeine doses or placebo conditions in every session and blood samples collected in pre-test and post-test. Results indicated there were significant differences between caffeine doses for GSH and vitamin E, but it was not significant for MDA (P<0.05). Also, there were significant differences between 9 mg.kg-1caffeine to placebo and 5 mg.kg-1 caffeine to placebo for GSH and MDA (P<0.05). Although there were no significant differences between 5 mg.kg-1 caffeine to placebo for vitamin E (P <0/05), but these differences between 9 mg.kg-1 caffeine to placebo were significant (P<0.05). In conclusion, different caffeine doses decreased EIOS and effectively augmented non enzymatic antioxidant status. It seems 9mg.kg-1 caffeine dose in comparison of 5 mg.kg-1 more effectively increases non enzymatic antioxidant status after incremental exercise.

Free Radicals, Incremental Exercise, Glutathione.