The effect of garlic supplementation on indices of blood oxidative stress response after an incremental resistance exercise

Introduction: This study aimed to investigate the effect of garlic supplementation on oxidative stress markers (AST, ALT, LDH, and CPK) following progressive resistance exercise. Methods: This research was a double-blind clinical trial with repeated measures. After obtaining informed consent, 20 sedentary females participated in this study (age: 23.15±2.65 years, BMI: 22.93±1.25 kg.m2). They were then randomly assigned to two groups of garlic supplementation (N=10) and placebo (N=10). After 14 consecutive days of supplementation (500 mg garlic or lactose every 12 hours a day), all the participants performed a progressive resistance exercise protocol. The changes in oxidative stress markers were measured in four phases (before supplementation and before, immediately after and 24 hours after the resistance exercise protocol). The data were analyzed by repeated measures analysis of variance with Bonferroni post hoc test and independent t- test at significance level of P≤0.05. Results: The results showed that the garlic supplementation after resistance exercise significantly decreased some of oxidative stress markers, that is, ALT (p=0.001) and AST (p=0.001). However, other markers (LDH, CPK) did not change significantly. Conclusion: The results of this study showed that the garlic supplementation leads to a decrease in some of oxidative stress markers. Therefore, garlic supplementation may be able to reduce the oxidative stress following the progressive resistance exercise.