Do Your Muscles Have Enough Carnosine?

  • By Matt Fitzgerald
  • Published Nov 17, 2011
Photo: Ryan Bethke

Beta-alanine supplements are purported to increase high-intensity exercise performance. But are they relevant to triathletes?
Written by: Matt Fitzgerald
Recently supplement makers have begun to market beta-alanine products specifically to triathletes and other endurance athletes. What is beta-alanine? How does it work? And could it make you a better triathlete?

Beta-alanine is a non-essential amino acid that is obtained in the diet primarily from meats containing carnosine, a naturally occurring peptide made up of beta-alanine and l-histidine. Beta-alanine serves a variety of functions in the body, but perhaps its most important role is to help formulate carnosine, which is not absorbed intact from food sources.

Photo: Ryan Bethke

Carnosine has long been celebrated as an “anti-aging” compound because it is an antioxidant, it prevents glycation (a processes whereby excess sugar in the bloodstream damages body proteins and accelerates the functional decline of organs), and it extends the lifespan of individual cells. But more recently scientists have discovered that carnosine has a significant role in exercise performance. Specifically, it helps the muscles maintain normal pH levels during intense exercise, when there is a tendency for the muscles too become too acidic, hastening fatigue.
Several studies on beta-alanine supplementation have found that it increases anaerobic endurance, or fatigue resistance in exhaustive or repeated efforts at very high intensities. The question is whether these benefits are relevant to triathletes, who train and race mostly at lower intensities.

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In 2009, researchers at the University of Oklahoma investigated the effects of beta-alanine supplementation on body composition and endurance performance when combined with high-intensity interval training. Forty-six men were divided into two groups, one of which received supplemental beta-alanine daily and the other of which received a placebo while engaged in a six week high-intensity interval training program. At the end of the program, members of the beta-alanine group exhibited greater improvements in VO2peak, total anaerobic work capacity, time to fatigue and lean body mass.

A more recent study from the Catholic University of Leuven, Belgium, has shown that beta-alanine supplementation may enhance performance in endurance cycling–sort of. Subjects received either a beta-alanine supplement or placebo daily for eight weeks. Before and again after the intervention all of the subjects performed a 10-minute time trial and a 30-second sprint at the end of a simulated 110-minute cycling race. Beta-alanine did not improve performance in the time trial compared to placebo, but in the closing sprint it improved mean power output by 5 percent and peak power output by 11.4 percent.

That’s pretty interesting, but again: Is it relevant to triathletes? A more recent study of the effects of beta-alanine supplementation on cycling performance may or may not get us closer to an answer. In this one a team of researchers measured time to exhaustion at an extremely high cycling intensity in 25 subjects on two occasions four weeks apart. During the four-week interval between tests the subjects took daily doses of either beta-alanine, a placebo, sodium bicarbonate (another acid-buffering supplement), or both beta-alanine and sodium bicarbonate. Performance in the high-intensity ride to exhaustion increased by 12.1 percent in the beta-alanine group, compared to just 1.6 percent in the placebo group.

Based on these findings, if I were a track cyclist whose races lasted no longer than a few minutes I would take beta-alanine. For triathletes it’s tougher to decide whether beta-alanine is worth taking. It certainly has no direct effect on performance in triathlons lasting one to 17 hours. But every triathlete should include a small amount of very short, very high-intensity intervals in his or her training. Beta-alanine supplementation is likely to increase the benefit you get from such training and may thereby slightly improve your performance in triathlons—or at least in your finishing kick!

Note that there is one strange but totally harmless side effect of beta-alanine supplementation, which affects roughly half of those who take it. “Parathesia” is a transient and benign tingling sensation in the upper extremities resulting from beta-alanine’s actions as a neurotransmitter. Some people find it very uncomfortable, others like it.
Matt Fitzgerald is the author of Iron War: Dave Scott, Mark Allen & The Greatest Race Ever Run (VeloPress 2011) and a Coach and Training Intelligence Specialist for PEAR Sports. Find out more at

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FILED UNDER: Nutrition

Matt Fitzgerald

Matt Fitzgerald

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