Muscle contains significant quantities of a substance called carnosine, an important buffer that soaks up acid in muscle. Therefore, increasing carnosine may delay fatigue and increase performance. Carnosine is made from two amino acids: L-histidine and beta-alanine. beta-alanine is rate-limiting in the synthesis of carnosine levels in muscles. Several studies have shown improvements with beta-alanine supplementation during multiple bouts of high intensity short duration activity and single bouts of high intensity exercise lasting more than 60 sec. Another strategy to enhance buffering capacity is to supplement with sodium bicarbonate, the main buffer in the bloodstream. Several studies have shown improvement in high intensity performance after sodium bicarbonate supplementation. Interestingly, no studies have examined the combination of beta-alanine and biocarbonate on performance. Researchers from the United Kingdom had healthy men supplement for 4 weeks with either beta-alanine (6.4 grams per day) or a Placebo. Before and after supplementation they performed a cycling test to exhaustion at an intensity that caused them to fatigue in about 2 minutes. After 4 weeks of beta-alanine supplementation they ingested either maltodextrin or sodium bicarbonate before the cycling test. Results showed that 4 weeks of beta-alanine supplementation allowed subjects to exercise for about 17 seconds longer when they ingested maltodextrin and 23 seconds longer when they ingested sodium bicarbonate. The effect of bicarbonate was found not to be significant but the authors noted that there was a 70% probability of a meaningful positive effect. What this means is that 4 weeks of beta-alanine supplementation increased performance by about 15%, and ingesting sodium bicarbonate before an exercise challenge improved performance beyond that of beta-alanine indicating a potential additive effect.
. Sale C, Saunders B, Hudson S, Wise JA, Harris RC, Sunderland CD. Effect of β-alanine plus sodium bicarbonate on high-intensity cycling capacity. Med Sci Sports Exerc. 2011 Oct;43(10):1972-8. PubMed PMID: 21407127.