Body builders across the board recognized and experienced for themselves as early as the 1970s that amino acids are important for building muscle. Even today, sports, particularly strength training, are still the most well-known applications for proteins and isolated amino acids.

Whey protein is isolated from whey, the liquid material created as a by-product of cheese production. The protein is characterized by its balanced amino acid profile.

With a biological value of approx. 100, whey protein can be used as effectively as whole egg protein by the body to build muscle. The biological value can be increased through specific supplementation with L-arginine.

Creatine is not a proteinogenic amino acid, but an energy supplier.

BCAA are branched chain amino acids: leucine, isoleucine, and valine. Several studies have found that leucine, in particular, can stimulate muscle growth. This is beneficial not only to bodybuilders, but also to patients with muscle atrophy.
L-arginine promotes good perfusion of muscle tissue (the “pumped” look). However, in very high doses (in excess of 15,000 mg per day), it may also stimulate the development of growth hormones.

Supplementation with L-arginine when taking whey protein improves the biological value of whey protein.

L-carnitine is important for lipid metabolism. There are indications that carnitine can boost fat burning in intensive training. There is even more evidence that taking carnitine can decrease recovery time after physical activity and reduce the likelihood of injuries.

Various Proteins for Muscle Building

Which protein supplementation is best for strength training is a topic that is often and hotly contested by athletes and scientists. Defining the quality of a protein is also difficult. The following properties determine quality:

Digestibility and Absorption Rate

Proteins for Building MuscleDigestibility refers to how much of the ingested protein remains in the body and how much is eliminated unused. The digestibility of milk and a varied diet is approx. 96%, meat has a digestibility of around 90%, wheat and oats approx. 86%, and rice around 76%.

Absorption rate refers to how quickly the body can convert the proteins into a usable form. Proteins derived from meat or plants must first be split in the stomach.

Protein shakes made from powder and milk, on the other hand, can be absorbed faster by the body. Free-form amino acids are more easily absorbed than protein hydrolysates (for example whey protein, soy protein, and casein).

Biological Value

Biological value is the most common means of determining protein quality. It is an index that shows how effectively body protein can be derived from one gram of the food protein.

The index is relative to the efficiency of whole egg protein (BV = 100). For example, if 2 grams per kg body weight are required of a certain protein vs 1 gram per kg of bodyweight of whole egg protein, then that particular food protein has a biological value of 50.

If a protein is deficient in one of the essential amino acids, no body protein can be produced. The biological value is zero.

Whey protein or casein?

There is a difference between whey protein and casein. Which one is better is hard to say. It depends on the situation and you should decide for yourself:

CharacteristicCaseinWhey Protein
Biological value77104
Delayed protein absorption34% in 5 hoursno
New protein formation31% in 100 minutes68% in 100 minutes. Zero after 300 minutes
Oxidation of amino acidslowhigh
Improvement of Nitrogen Oxide (NO) levelsvery goodweak
Improvement during diet / weight lossVery good: Decrease in fat tissue by 7,0 Kg in 12 weeksmedium: Decrease in fat tissue by 4,2 Kg in 12 weeks
Other health benefits observed in studiesIncrease of HDL-Cholesterine, decrease of lipoproteins, lower risk of thrombocytesIncrease of HDL-Cholesterine, decrease of triglycerids, lower blood pressure, strengthening of immune system, better Glutathion level in plasma
Glutamine contenthighlow
BCAA contentmediumhigh

How effective is soy protein for muscle building?

In the world of body building, soy protein has not garnered much attention, and sometimes undeservedly so. It is relatively low-cost, and in terms of muscle building effectiveness, it is comparable to meat protein 1. In several studies, soy protein led to improvements in serum lipid levels.

Studies show mixed results with regard to effects on growth hormones and testosterone levels. In some studies, increases in testosterone levels were reported, in others a decrease was observed 2.

The reason is that soy protein concentrate contains daidzein and genistein, two isoflavones that are phytoestrogens. However, isolated soy protein does not contain these hormones.

Cheap, poorly manufactured soy protein concentrates may also contain so-called antinutrients. These are substances that prevent the absorption of nutrients in the stomach and intestine.

Another disadvantage is that soy protein contains relatively little and poorly digestible methionine. Methionine is the precursor to glutathione, a very important antioxidant.

Isolated Amino Acids

Isolated amino aids are readily available and can thus supplement protein supply, especially in training or in support of muscle building.


The branched chain amino acids leucine, isoleucine, and valine are of particular importance in muscle building, but also serve as energy suppliers. BCAA thus especially lend themselves to supplementation with whey protein or other complete amino acid combinations.


Supplementation with l-arginine is popular with body builders on account of the following three effects:

  1. it improves perfusion and gives you the “pumped” look;
  2. there is some evidence that dosages in excess of 15,000 mg may promote the release of growth hormones; and
  3. arginine improves the biological value of whey protein.

BCAA, Arginine, and Muscle Building

The effect of concentrated arginine intake on growth hormones, particularly HGH (human growth hormone), continues to be discussed. A study on this topic was published as early as 1969 3. The effect is still controversial among scientists.

With low doses below 20,000 mg per day, it is not expected that growth hormones are released through supplementation with L-arginine or the combination of L-arginine with ornithine or lysine. Taking supplemental L-arginine to support muscle building is generally recommendable, but you should not expect any miracles.

L-arginine is currently often combined with Bioperin®. The black pepper extract Bioperin® is known to improve the absorption of vitamins, amino acids, and also medication.


Creatine is an energy supplier that is not directly required to build muscle mass. Creatine is synthesized in the liver, pancreas, and kidneys using the amino acids L-arginine, glycine, and methionine. Creatine is not an amino acid, but a tripeptide (three amino acids bound together).

The amount the body can produce on its own is approximately 2 grams per day. Creatine is an energy supplier that is stored in muscle tissue. As soon as the body has used up its very limited reserves of ATP, it turns to creatine for energy generation.

Taking creatine is therefore recommended for activities that involve short bursts of intense exertion. The recommended dosage in athletics is approx. 20 grams to 30 grams per day in the loading phase, and 3 grams to 5 grams per day during the maintenance phase.

During the training phase, athletes can follow one of two strategies in creatine supplementation: “Fast Load” and “Slow Load“. A Fast Load entails taking 20 grams (at a body weight of 70 kg) per day for a period of five days.

This amount should be divided into five individual dosages. This regimen is followed by a dose of 3 grams creatine per day for several months.

A Slow Load consists of taking 5 grams of creatine a day for a period of four weeks. Subsequently 3 grams of creatine are taken daily.

More about amino acids and building muscle mass


  1. Young VR, Wayler A, Garza C, Steinke FH, Murray E, Rand WM, Scrimshaw NS. A long-term metabolic balance study in young men to assess the nutritional quality of an isolated soy protein and beef proteins. American Journal of Clinical Nutrition. 1984. 39(1):8-15
  2. Various studies quoted by Arndts K. Protein and Amino Acid Manual. 2004. 88
  3. Merimee TJ, Rabinowitz D, Fineberg SE. Arginine-Initiated Release of Human Growth Hormone — Factors Modifying the Response in Normal Man. New England Journal of Medicine. 1969. 280:1434-1438
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