The sports supplement market is big business, but the reality is that most of these supplements have little evidence for a benefit. It is not all negative news though because there is a small group of supplements that are backed by science and which can play a performance-enhancing role in some athletes. In this series on sports supplements, I will profile this group of supplements and for this podcast, the spotlight is on beta-alanine.

Beta-alanine is a non-essential amino acid that has recently received a lot of attention from exercise researchers and athletes. Beta-alanine is naturally made in the body, but unlike most amino acids that are used to make proteins, beta-alanine has a different fate. Instead, together with the amino acid histidine, it produces a molecule called carnosine. Carnosine has several roles in the body, although its function as a muscle buffer is the one of most interest to exercise scientists.

In your muscles, histidine levels are normally high and beta-alanine levels low, which makes beta-alanine the rate-limiting step in the production of carnosine. The top food sources of beta-alanine are meat, poultry and fish so vegetarians and vegans tend to have less carnosine in their muscles compared to omnivores. Although most people can get sufficient amounts of beta-alanine from their diet, supplements raise its levels even further.

Acting as a buffer inside the muscle, carnosine can soak up excess hydrogen ions that are generated during short-term, high-intensity anaerobic exercise. These hydrogen ions contribute to muscle acidosis which can lead to muscle fatigue. Carnosine acts by mopping up these hydrogen ions to regulate muscle pH and increase resistance to muscle fatigue and potentially increase training capacity and performance.

So, increasing muscle carnosine stores can, in theory, improve muscle pH regulation. If you caught last week’s podcast on sodium bicarbonate, you’ll appreciate the benefit that acid-base buffers can play in helping with high-intensity exercise. Supplementation with beta-alanine has been shown to raise the concentration of muscle carnosine, which enhances the muscles’ buffering capacity.

Beta-alanine was one of the few supplements to get an endorsement for having good evidence behind it in the 2018 IOC Consensus Statement on dietary supplements for use by high-performance athletes and I’ll link to this document in the show notes https://bjsm.bmj.com/content/52/7/439

So, let’s look at those benefits closer. Supplementation with beta-alanine has shown a benefit in high-intensity sports of 1 to 7 minutes in duration such as sustained sports like rowing, track cycling, swimming and middle-distance running. It also shows a benefit in sports that involve repeated high-intensity efforts of exercise such as resistance training, team sports and racquet sports.

The magnitude of benefit of beta-alanine is variable, but improvements in performance of up to about 3 percent have been seen in some athletes in both continuous and intermittent exercise tasks of 30 seconds up to 10 minutes in duration. It seems though that the more trained an athlete is, the smaller the effect beta-alanine is likely to have.

Beta-alanine has also been shown to enhance muscular endurance in a gym setting with reports of people being able to perform one or two additional reps when training in sets of 8–15 repetitions. However, there's no consistent evidence that beta-alanine improves strength.

Beta-alanine stays around in the body for some time, so stores can be built up over several weeks. A typical loading protocol is the daily consumption of 65 mg of carnosine per kg of body weight, taken as split doses every 3-4 hours over the day. So, for a 70 kg athlete, that’s about 4.5 grams of beta-alanine split into several smaller doses over the day. And this dosing regimen is normally maintained for 10 to 12 weeks. But timeframes of 4 to 8 weeks may prove to be just as effective. After stopping supplementation, it takes about 3 months for muscle carnosine levels to return to starting concentrations.

Beta-alanine is a popular supplement to take along with sodium bicarbonate and creatine, both supplements I’ve covered in previous podcasts.

Outside of the world of sports performance, animal and test-tube studies suggest that carnosine has antioxidant, anti-ageing and immune-enhancing properties. But it is way too early to say if humans would get any of these benefits.

Side effects

What about side effects? The evidence is clear that beta-alanine can be safely used by healthy people at doses of up to 6.4 g/day for up to 6 months. The only known adverse side effect of beta-alanine supplementation is a ‘pins and needles’ sensation that occurs with high single doses. And this tingling can happen within a few minutes of taking so it can freak you out if you aren’t aware of this. The pins and needles effect is harmless and passes quickly and can be reduced by using slow-release preparations or split dosing strategies. Some athletes like the pins and needles effect from taking beta-alanine so take higher doses rather than split these over the day. Whatever floats your boat.

Beta-alanine is one of the few nutritional supplements for which research has consistently shown a sports performance benefit. The use of all supplements and sports foods by athletes though involves a balance between the potential benefits set against potential risks such as health side-effects, anti-doping rule violations from contamination, and redirection of resources from real performance-enhancing factors. So, take this into account when considering taking any sports supplement. And seek out personalised advice from a sports dietitian. You can connect with an Accredited Sports Dietitian as well as access a great range of resources through the website of Sports Dietitians Australia at www.sportsdietitians.com.au

So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on if it supports it, or else head over to my webpage www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.

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I’m Tim Crowe and you’ve been listening to Thinking Nutrition.