Background and Objectives: there is lack of evidence on the effect of  β-Alanine supplementation on performance in the short time and intense activities. The aim of this study is to determine the effect of β-Alanine supplementation on serum lactate response and muscular endurance in male bodybuilders.

Materials & Methods: Twenty bodybuilders (age: 21.1±0.87 yr, height: 176. 75±1. 82 cm and weight: 77. 24±1. 32 kg) participated for this study. Subjects were divided in two groups consuming β-Alanine  supplementation (3 gr /day) and placebo (dextrose) in a double blind design. Before and after supplementation, serum lactate indices and muscular endurance were measured. Blood samples were collected from the subjects before and after receiving supplementation or the placebo. For data analysis from Independent t and Paired t test was used to determine differences in the groups and significance level was considered p<0. 05.

Results: The results showed that upper body muscular endurance (p =0.023) and lower body (p =0. 027) have significantly increased in β-Alanine group compared to the placebo group. In the lactate variable, in the group of β-Alanine, significant changes were not observed compared to the placebo group (p = 0. 92).

Conclusion: Supplementation with β-Alanine (3 g / day) caused a significant increase in muscle endurance but nosignificant decrease in serum lactate was detected.