The Effect of Whey Protein Supplementation after Eccentric Resistance Exercise on Glutathione Peroxidase and Lactate Dehydrogenase in Non-Athletic Young Men

Background: Laboratory studies have revealed that intense exercise is associated with increased production of free radicals, and weakened capacity of antioxidant. The aim of the study was to determine the effect of short-term whey protein supplementation on some oxidant and antioxidant indices following an intense exercise session among nonathletic men. Methods: In this double blind randomized clinical trial study, 24 nonathlete male students (21.9 ± 1.19 kg of weight) without any chronic and metabolic diseases were randomly allocated into two groups: males who received whey protein supplement (0.4 g / kg body weight for 3 consecutive days), and those who received placebo. Blood samples were collected before, immediately, 24, 48, and 72 hours after an intense resistance exercise session, and were analyzed for glutathione peroxidase (GPx) and Lactate dehydrogenase (LDH). The repeated measure ANOVA was used to compare GPx and LDH between these two groups. Results: Significant differences were observed in the GPx change pattern between the two groups. On the other hand, at each stage of the sampling, there was a significant increase in the amount of GPx compared to placebo group (1.164 ± 0.166 vs 0.924 ± 0.054 for 24 recovery; 1.111 ± 0.104 vs 0.896 ± 0.105 for 48 hours recovery; 1.036 ± 0.131 vs 0.873 ± 0.083 for 72 hours recovery) (Pvalue < 0.05). However, no significant difference was observed in the LDH change pattern between the two groups (Pvalue = 0.99). Conclusions: Whey protein supplementation is associated with the improvement of GPx activity after an intense resistance exercise among non-athletic young men.