Muscle contains significant quantities of a substance called carnosine, an important buffer that soaks up acid and therefore may allow muscles to contract longer and harder. Beta-alanine is rate-limiting in the synthesis of carnosine levels in muscles.

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 in doses between 200 mg and 300 mg per kilogram of body weight. Interestingly, no studies have examined the combination of beta-alanine and bicarbonate on performance.

Researchers from the United Kingdom had healthy men supplement for 4 weeks with either 6.4 grams of beta-alanine per day or a placebo. Before and after supplementation, the men 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, the men ingested 24 grams of 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.

Thus, 4 weeks of beta-alanine supplementation increased performance by 15%, and ingesting sodium bicarbonate before an exercise challenge improved performance beyond that of beta-alanine, indicating a potential added effect. 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. 

Reference: Med Sci Sports Exerc. 2011 Oct;43(10):1972-8. PubMed PMID: 21407127.

Dr. Jeff Volek is a registered dietitian and Full Professor in the Department of Human Sciences at The Ohio State University. He has published 270 articles examining health and performance effects of low-carbohydrate diets and other dietary supplements including seminal work on creatine, carnitine and whey protein.