BCAAs: What they are for, when to take them and what the science says

Branched-Chain Amino Acids (BCAAs) are one of the most popular supplements among athletes. Their proponents claim that they help repair muscle, increase muscle growth, protect the immune system, and even reduce muscle soreness. But what does the science say? We take a look at the claims surrounding BCAAs, their true role in muscle synthesis, and when they may be a good idea to supplement.

In the article you will learn

• What are BCAAs – how do they work and why are they popular among athletes?

• Do BCAAs support muscle growth? – what effect do they have on protein synthesis and why are they not enough on their own.

• BCAAs and regeneration – do they really help reduce muscle soreness and speed up recovery?

• BCAAs during endurance training – can they improve performance and delay fatigue?

• When does it make sense to take BCAAs – for whom can they be useful and when are they unnecessary?

• What is the recommended dosage - when and how much BCAA to take for maximum effect.

How do BCAAs work and what do they promise?

BCAAs (leucine, isoleucine, valine) are essential amino acids that the body cannot produce on its own. This means we must get them from food or supplements. They are most often promoted for their role in:

• Muscle protein synthesis (MPS) – a process that is key to muscle growth.

• Inhibition of muscle breakdown (MPB) – protection of muscle mass during intense training or dieting.

• Reducing muscle pain – accelerating regeneration after strenuous training.

• Improving sports performance – supporting metabolism during physical activity.

It sounds great on paper. However, as studies show, many of these claims are based on incomplete or weak evidence.

BCAAs and Muscle Growth: Reality vs. Myth

The main reason people take BCAAs is the promise of muscle growth support. Here's where the truth gets more complicated:

1. Stimulation of the mTOR pathway
   Leucine, a key component of BCAAs, activates mTOR, the molecular pathway responsible for muscle protein synthesis. This means that BCAAs can kick-start the muscle-building process.

2. Lack of other amino acids
   However, BCAAs alone are not enough. Muscle needs all nine essential amino acids (EAAs) to grow. Studies have shown that while BCAAs stimulate protein synthesis, this stimulation is significantly less than when consuming a complete protein source such as whey protein.

3. Results compared to total protein
   Supplementing with BCAAs alone only provides partial "building blocks" needed for muscle recovery. For example, after exercise, BCAAs increased muscle protein synthesis to only half the level achieved after consuming whey protein.

Verdict: BCAAs can support muscle growth, but their effectiveness is lower than when consuming complete protein sources. Therefore, to support muscle growth after training, it is better to use a product that contains complete protein, such as whey protein or a recovery drink.

Source: hyve

Do BCAAs relieve muscle pain and promote regeneration?

Another popular claim is that BCAAs help reduce muscle soreness after exercise and speed up recovery. What does the science say?

• Reducing muscle pain
  Some studies suggest that BCAAs may slightly reduce soreness after intense exercise. However, research shows that this effect is relatively small and does not lead to significant improvements in muscle function.

• Muscle regeneration and protection
  BCAAs may reduce muscle breakdown during endurance exercise, but there is no conclusive evidence that they speed up recovery.

Verdict: BCAAs' effects on recovery and muscle soreness are weak and impractical for most athletes. However, they may help protect muscles in certain situations.

The role of BCAAs in endurance exercise

During endurance exercise, such as long-distance running or cycling, BCAA levels in the blood drop. This can contribute to fatigue because the decline in BCAAs increases serotonin production, which signals fatigue in the brain. BCAA supplementation can mitigate this process and support performance.

• Performance benefits : One study found that marathon runners who consumed a sports drink containing BCAAs increased their performance by up to 4% .

• Mental and physical support : BCAAs can improve both psychological and physiological responses during training, meaning athletes feel better both mentally and physically.

• Dosage : It is recommended to take 2-4 grams of BCAA per hour with a solution containing 6-8% carbohydrates and electrolytes during prolonged physical activity.

However, not all studies confirm the positive effect of BCAAs on performance, so we leave it up to you to try incorporating BCAA supplementation into your nutritional regimen yourself.

Source: hyve

BCAA as fuel during endurance exercise

Endurance athletes use BCAAs as fuel during long, intense workouts. This is especially relevant when carbohydrate intake is inadequate . A lack of carbohydrates increases the body's need to draw energy from BCAAs stored in the muscles.

Note: If you have sufficient carbohydrate intake, the body primarily uses carbohydrates as an energy source, which reduces the need to draw energy from BCAAs. However, we know from experience how difficult it is to consume enough energy during intense training periods to avoid muscle tissue breakdown.

When does it make sense to take BCAAs?

Although BCAAs are not necessary for everyone, there are situations where they may make sense:

1. Low-protein diet
   For those who cannot consume enough protein from food, BCAAs can be a supplement to maintain muscle mass.

2. Specific diets (vegans and vegetarians)
   Plant-based proteins often have lower BCAA content, so supplementation may be helpful.

3. During long endurance training
   During long endurance activities, BCAAs can help reduce muscle breakdown under certain circumstances.

4. Better timing around exercise : BCAAs or EAAs are rapidly absorbed and can be easily included before or after training when consuming a full meal is not possible.

5. Ensuring digestive comfort : For athletes who have difficulty tolerating a fuller stomach during intense physical activity, BCAA or EAA supplementation may be a gentler alternative.

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Resources:

1. Jackman SR, Witard OC, Philp A, Wallis GA, Baar K, Tipton KD. Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis Following Resistance Exercise in Humans. Front Physiol. 7;8:390, 2017.
2. Jackman SR, Witard OC, Jeukendrup AE, Tipton KD. Branched-chain amino acid ingestion can relieve soreness from eccentric exercise. Med Sci Sports Exerc. 42(5):962-70, 2010.
3. Blomstrand, E. 2006. A role for branched-chain amino acids in reducing central fatigue. Journal of Nutrition 136: 544S-547S.
4. Carli, G., et al. 1992. Changes in exercise-induced hormone response to branched chain amino acid administration. European Journal of Applied Physiology 64: 272-277.
5. Hassmen, P., et al. 1994. Branched-chain amino acid supplementation during a 30-km competitive run: Mood and cognitive performance. Nutrition 10: 405-410.