Objective The use of amino acid supplements among athletes for reducing muscle injuries has become more popular. This study aims to examine the effect of branched-chain amino acids (BCAA) consumption before exhaustive exercise along with one month vitamin E supplementation on lactate dehydrogenase (LDH) and creatine kinase (CK) levels of active females.
Methods In this study, 32 active female students of Razi University in Kermanshah, Iran aged 18-23 years were selected and, after obtaining the informed consent form them, were randomly divided into four groups of placebo (n=8), Vitamin E (n=8), BCAA (n=8), and Vitamin E+BCAA (n=). Vitamin E was consumed as 400 IU daily for a month and BCAA with lemon juice was consumed 2.5 hours before exercise four times with a 30-min interval. The exercise program included 30 minutes of cycling on an ergometer with 50% of the aerobic capacity, and immediately followed by cycling with 75% of the aerobic capacity until the exhaustion. Sampling was done immediately and 48 hours after the exercise, and data were analyzed using Shapiro-Wilk test, repeated measures ANOVA, Bonferroni test, and Pearson correlation test in SPSS software, version 22.
Results None of the supplements had a significant effect on levels of LDH and CK immediately after the exercise (P>0.05), but 48 hours after the exercise, the mean levels of LDH and CK decreased in BCAA group (CK: 199.4±11.00, LDH: 213.2±23.44) and Vitamin E+BCAA (CK: 188.3±3.20, LDH: 208.3±40.12) compared to Vitamin E and placebo groups (P = 0.001). Their lowest levels was observed in the Vitamin E+BCAA group which was negatively correlated to plasma leucine and isoleucine levels (P = 0.001).
Conclusion Although BCAA consumption alone before exhaustive exercise can reduce muscular damage indicators in active females, it seems that leucine and isoleucine along with Vitamin E supplementation is more effective in reducing muscular damage.