EAAs and BCAAs
Also called: essential amino acids, branched-chain amino acids, leucine, isoleucine, valine, BCAA 2:1:1, amino acid powder.
Amino acids sold to protect muscle; BCAAs on their own build no protein, and EAAs duplicate a diet that is already sufficient.
What it is
Essential amino acids (EAAs) are the nine the body does not make; BCAAs (leucine, isoleucine, valine) are three of them, including leucine, which triggers the signalling for protein synthesis. Every complete protein contains all of them. People buy them as flavoured powders for recovery, against "catabolism" and for fasted training.
What the label does not say
- BCAAs on their own are not enough. Wolfe (2017) concludes that it is theoretically impossible for them to create an anabolic state, because the six other essential amino acids then have to come from the breakdown of muscle protein. In a trial, 5.6 g of BCAAs after training raised myofibrillar synthesis by 22%, about 50% less than whey containing the same amount of BCAAs (Jackman 2017).
- Pointless if protein intake is sufficient: Examine sums up that supplementation improves neither strength nor hypertrophy when protein intake is adequate, and the NIH points out that every complete protein automatically provides the BCAAs. The Australian Institute of Sport places BCAAs in its Group C, reserved for supplements whose data do not support a benefit or are lacking.
- Leucine is the signal, not the brick. The ISSN (International Society of Sports Nutrition) puts the per-meal threshold at 700 to 3,000 mg of leucine accompanied by a balanced array of essential amino acids, which 20 to 40 g of a complete protein provides; with a whey at 11% leucine (Gorissen 2018), 25 g brings about 2.7 g.
- Proprietary blends hide the doses: across 100 pre-workouts, 44.3% of the ingredients were declared without a quantity. A "5 g amino acid complex" says neither how much leucine it contains nor whether all nine essentials are in it. Health Canada adds proteins and amino acids together under a ceiling of 90 g per day.
The forms on the shelf
- BCAAs, often in a 2:1:1 ratio (leucine, isoleucine, valine): three amino acids out of nine. Health Canada requires all three to be present and sets leucine between 147 mg and 7 g per day.
- EAAs: the nine essential amino acids, in proportions that vary by product; Health Canada caps tryptophan at 220 mg and methionine at 1 g per day, for example.
- In pre-workouts: 3.2 ± 1.9 g of BCAAs per serving on average across the 100 products analyzed by Jagim (2019), often in a proprietary blend.
Published reference values
- Health Canada (Workout Supplements monograph): leucine 147 mg to 7 g per day, isoleucine 66.5 mg to 3.5 g, valine 84 mg to 3.5 g; lysine up to 3 g, methionine 1 g, tryptophan 220 mg.
- NIH: 10 to 14 g per day of supplemental BCAAs could help gains in mass and strength with training; little data in endurance.
- ISSN: 0.25 g/kg or 20 to 40 g of quality protein per meal, with 700 to 3,000 mg of leucine, every 3 to 4 hours. No upper limit in the sense of the dietary reference intakes for these amino acids.
When
Around training if the goal is protein synthesis, but a 20 to 40 g serving of complete protein does the same thing while also bringing the building material.
To mention to a professional
- Liver or kidney disorder (Health Canada requires advice above 30 g per day of proteins and amino acids), pregnancy and breastfeeding: check with a health care professional.
What it is sold for, and what the data show
These powders are sold for recovery, muscle protection and fasted training. EAAs genuinely stimulate protein synthesis, and Examine notes a reduction in muscle soreness 24 to 48 hours after exercise with BCAAs, without faster recovery of performance. But in someone eating 1.4 to 2.0 g/kg of protein, no data show additional gains in mass or strength, and BCAAs on their own cannot build protein. The promise sells a fraction of what a scoop of protein powder or a meal already contains.
From the plate first
Every complete protein (meat, fish, eggs, dairy products, soy) contains the nine essential amino acids; whey is the richest in leucine, at about 11% of its protein according to Gorissen (2018).
Sources
- Wolfe, Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?, JISSN 2017
- Jackman et al., Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans, Frontiers in Physiology 2017
- Examine.com, Branched-Chain Amino Acids
- Jäger et al., ISSN position stand: protein and exercise, JISSN 2017
- NIH Office of Dietary Supplements, Dietary Supplements for Exercise and Athletic Performance (Health Professional)
- Health Canada, natural health product monograph, Workout Supplements
- Australian Institute of Sport, Sports Supplement Framework, Group C
- Jagim et al., Common Ingredient Profiles of Multi-Ingredient Pre-Workout Supplements, Nutrients 2019
- Gorissen et al., Protein content and amino acid composition of commercially available plant-based protein isolates, Amino Acids 2018
Educational information, drawn from the sources above. It does not replace the advice of a health professional, who remains the reference for your situation, your medications, pregnancy or breastfeeding.