Acute effects of different doses of beta-alanine supplement on neuromuscular fatigue and lactate accumulation after intense interval exercise

Some studies have shown that beta-alanine supplementation may delay fatigue during strenuous exercises. This study examined the effect of 10 days of β-alanine supplementation with different doses on neuromuscular fatigue and blood lactate levels. Material & Methods: This study was conducted on 40 active men with a mean age of 21.9±2.6 years and body mass index 24.54±1.8 kg/m2 who were randomly divided into four groups of 10 people as follows: receiving doses of 2, 4 and 6 grams of beta-alanine supplement (experimental groups) and placebo (control) group. Competitors completed four 30-second Wingate tests with maximum power, before and after 10 day beta-alanine supplementation period. A 4-minute rest interval was set between each exercise. At each step, the first and second blood sampling administrated before the 1st exercise and 6 minutes after finishing the 4th exercise, respectively. The EMG amplitude as neuromuscular fatigue index was measured before the first Wingate and during the fourth Wingate test. Results: Supplementation with different doses of β-alanine had no effect on M-wave amplitude in vastus lateralis muscle. In other words, none of the within-group (P=0.078) and between-group (P=0.66) changes were significant. Moreover, after repeated Wingate exercises, amount of lactate in all groups (received β-alanine supplement and placebo group) increased significantly (p<0.001), while there was no difference between groups (p=0.1). Conclusion: The present findings suggest that doing repetitive maximal exercises result in significant increase of lactate, but short-term β-alanine supplementation with different doses has no effect on neuromuscular fatigue and blood lactate accumulation