Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In


Nutrition for Women

Your Muscle-Fatigue Fighter

Beta-alanine is gaining cred in the supplement world for its ability to help you work out past your threshold. Is it worth trying? Oxygen sifts through the latest science, and offers you the bottom line on this promising amino acid.

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.


What if there was something natural you could take to improve the quality of your workouts? Something that could help you blast through those high-intensity interval training (HIIT) cardio sessions, or help you rep to failure with a heavier dumbbell? Beta-alanine, a naturally occurring non-essential amino acid, is billed as the new performance-enhancing nutritional supplement that can give you, the active woman, that edge.

What It Is

Beta-alanine is found in the muscle of animal proteins (not in organ meats). It is a component of carnosine, a protein-like compound that appears to be concentrated in actively contracting muscles. Research has shown that athletes who naturally have high levels of muscle carnosine seem to be able to exercise with greater force, which can inevitably lead to muscular gains. For the average Jane, high muscle carnosine levels can be achieved with enough beta-alanine through supplementation.

Related:Power Booster

Beta-alanine also appears to be a buffering agent, meaning that it prevents certain enzymatic reactions that increase lactic acid in working muscles. Excess lactic acid buildup in your muscles, as you may already know, can cause you to fatigue earlier from exercise. Beta-alanine works to dampen the “burn” in your muscles when you work out. So the more beta-alanine in your system, the better you may be able to perform.

The Science Behind It

Scientists became interested in beta-alanine when they discovered a naturally occurring, unusually high level of carnosine in the muscles of a significant number of championship strength and power athletes. Because carnosine controls the natural rise in lactic acid that results from high-intensity exercise, these athletes could likely perform extra reps or a greater number of sprints before muscle burn forced them to quit. To help people who aren’t able to naturally produce high levels of muscle carnosine, initial studies tried supplementing the diet with carnosine. The results? It was found that carnosine was metabolized during digestion and did not raise muscle carnosine levels. So the researchers turned to supplementation with beta-alanine, the precursor to carnosine production, and saw that it could raise muscle carnosine levels. The next step was to show that the more beta-alanine in your muscles, the better you could perform.

And science has so far supported this: Supplementation with beta-alanine has been shown to increase muscle carnosine content, with the potential to improve endurance during high-intensity exercise, particularly during multiple bouts of high-intensity exercise and in single bouts of exercise lasting more than 60 seconds. Similarly, beta-alanine supplementation has been shown to delay the onset of neuromuscular fatigue. However, for the hard-training, weightlifting gal, it must be noted that beta-alanine supplementation, on its own, does not improve maximal strength or aerobic capacity, but rather enhances anaerobic (bursts of high-intensity exercise, the kind that leaves you breathless) threshold and time to exhaustion. However, while research on beta-alanine has been primarily positive, there are factors to consider.

Good For Women?

As with most supplement studies, research on beta-alanine has been largely conducted on men. But is it effective for women? Jeff Stout, PhD, and his team from the University of Oklahoma sought to answer this with two studies, one done in 2006 and the other in 2010. In the first study, they examined the effects of 28 days of supplementation with beta-alanine or a placebo on 22 women. The women then performed an incremental exercise test on a cycle ergometer to exhaustion. The result: the beta-alanine group significantly outperformed the placebo group in anaerobic, but not aerobic metabolic and performance measurements. Translation: it may help prevent you from losing steam in a spin class or similar high-intensity cardio program. In last year’s study, 44 women were split into three cycling groups who received beta-alanine, a placebo or no supplementation. The women trained for six weeks. While everyone improved their cardiovascular fitness, there were no measurable differences among them. The scientists concluded that HIIT was “an effective and time-efficient method” to boost fitness levels, but no measurable benefit from beta-alanine was shown.

Should You Try It?

Consider this: I have clients who won’t train without beta-alanine, and those who haven’t seen any difference in their training or race results despite supplementation. Most likely, this second set of clients is much like the original elite athletes studied for their naturally high levels of muscle carnosine, so supplementation doesn’t do much for them. For those less capable of producing carnosine, supplementation may work seemingly like magic to decrease muscle burn and fatigue, thereby enhancing performance. If you participate in high-intensity training and/or competition, then beta-alanine is worth a try.

How To Use Beta-Alanine

  1. Purchase “time-release” beta-alanine. This formula will eliminate paresthesia, a temporary tingling or itchy feeling in the hands or feet that occurs after consumption of regular blends.
  2. Loading phase: For three weeks, take three grams with your pre- and postworkout shakes. Continue with the same dose, even on your rest days, in order to load your muscles with beta-alanine.
  3. After the three-week loading phase, scale down the dosage, taking 1.5 grams twice daily, again, preferably before and after your workouts.

Fast Fact

Beta-alanine is available in both capsules and powder form, and is even mixed with creatine. In fact, one study has shown that beta-alanine combined with creatine delayed the onset of muscular fatigue better than beta-alanine or creatine alone.