What are amino acids?

Geschatte leestijd: 8 minuten Indeed, amino acids as the English name suggests, are the building blocks of protein and muscle tissue. All physiological processes related to sports – energy, recovery, muscle and strength gains, fat loss, mood, and brain function – are closely linked to these building blocks. It is therefore no wonder that amino acids play an important role as supplements for athletes, especially among bodybuilders.

Amino acids and protein

Amino acids are the molecular building blocks of protein. According to an accepted classification, nine of them are essential and indispensable amino acids, meaning they must be ingested through food or supplementation. The others are classified as non-essential or semi-essential, based on the body’s ability to make them from other amino acids. Although you probably don’t think about it when you eat a piece of meat, the number and balance of amino acids in food (especially the essential and semi-essential ones) determine the muscle-building value and health value of the protein or supplement. But that’s not all. In addition to the influence of carbohydrates, fats, and total calorie intake, protein quality is also related to the amount of specific amino acids (essential, semi-essential, and non-essential) it contains. Although the amount of essential amino acids is generally the most important, the semi- and non-essential ones are also important because the body’s synthesis of these is too slow to support maximum growth. Even if a food source has the perfect amino acid profile for a particular individual and lifestyle, another important factor must also be considered: The extent to which it is actually delivered to the tissues that need it. This also raises issues such as digestion, absorption, actual biological availability, and the potential value of supplementation.

Where are amino acids found

Eating high-quality food is the most normal way to get amino acids. This is especially true for foods high in protein such as lean meat and low-fat dairy products. Even some vegetables and beans contain a high concentration of most amino acids. For serious athletes and people who are often on the go, protein powders and pure supplements in tablet form offer an easy and effective way to supplement nutrition. Why would someone pay relatively much for just a few grams of pure supplements if you can easily obtain them from your diet? That’s because of biological availability. Biological availability determines the extent to which an administered substance reaches its site of action or use in the body. Biological availability is therefore a measure of supply efficiency: how much of the absorbed substance is actually used for the intended purpose. It is conceivable that two diets contain exactly the same amount of certain amino acids (the same profile), but cause large differences in absorption. Several factors affect biological availability.

Availability of amino acids

How fat you should eat a protein source, and the time it takes to make the digested amino acids available for use by the body, depends on several factors, such as:

1. Cooking: Amino acids are more or less sensitive to heat. Arginine, for example, is extremely stable and will only break down when exposed to a sustained temperature of about 243 °C. Carnitine breaks down at a temperature of 140 °C. Cooking, in addition to killing microorganisms, also causes the long spiral polypeptide chains to unravel, making the amino acid more vulnerable when it reaches the digestive system.
2. The composition of the food: Solid, liquid, powder, or tablet. Or, and to what extent, it is chemically pre-digested, and the type of binders, fillers, and other nutritious and non-nutritious substances
3. The state of the digestive system: Genetic, age, overall health, and specific diseases and conditions
4. Metabolism or consumption in the liver before entering circulation

For maximum effect, you should consume them on an empty stomach and in a dosage that ensures significant amounts reach the intended tissues. The most reliable way to deliver specific amino acids is to administer them specifically. The best biologically available source for oral intake is in the form of free-form supplements in powder form. A single (unbound) amino acid can raise its specific level in the general circulation within 15 minutes, making it immediately available for metabolism at the site where it is needed. Hence, for example, it is recommended to take BCAAs (branched-chain amino acids) before, during, and after exercise. This is to combat fatigue (physical and mental), as well as to provide energy to prevent muscle protein catabolism (breakdown) and to accelerate recovery.

Use of amino acids

Muscle tissue will grow if certain conditions are met, including exercise, the presence of hormones (growth hormone, insulin, testosterone, and thyroid hormone), and nutrients. Nutritional science has advanced to the point where athletes who supplement their diet with free-form amino acids can now get the essential amino acids – which have a high BCAA content – more effectively to their muscles. The key is the ‘window of opportunity’, the period of time during which the body is most susceptible to nutrient delivery. This is immediately after training; the body is then extra sensitive to nutrients, and blood flow to the trained muscles remains high. The secret to optimizing recovery and growth may be to eat a small meal consisting of protein with simple and complex carbohydrates. However, this is not the current high-tech approach. Often, if you train hard, you don’t feel much like eating right away, even if an easy and light nutritious meal was quickly available. More importantly, however, is the fact that a high-protein meal will only bring enough amino acids into your bloodstream a few hours after eating it, especially if blood flow to the stomach area is reduced due to a hard training session. What it comes down to is that even if you eat the right food quickly after training, the nutrients will arrive too late at your muscles to make proper use of the ‘window of opportunity’. Many athletes know very little about amino acids and protein, the different forms, and the best times to take them. Investing some time in researching this can pay off big time, in terms of physical growth and saving money.

Amino acids function

Supplement manufacturers have recognized that the potential value of using free-form amino acids was limited by the price and the lack of convincing and supportive research for several years. The popularity has risen dramatically recently. Pre-packaged training and recovery drinks with hydrolyzed (pre-digested) proteins and often some free-form amino acids now fill the refrigerators in the gyms. Capsules and free-form amino acids in powder form, even though it is still relatively expensive, are also increasingly used by a growing number of top amateur and professional athletes. The value of free-form aminos is especially that they do not require a digestion process. The term free-form means exactly that they are free from bonds to other molecules, allowing them to quickly leave the stomach and go to the small intestine, where they are rapidly absorbed into the bloodstream. After absorption, they are processed by the liver. For example, if you eat a steak, only relatively few amino acids escape the metabolic actions of the liver. However, the liver can process only a certain number at a time, and taking a dose of 3 to 4 grams of rapidly absorbing amino acids exceeds this limit. As a result, they are immediately sent to the tissues that need them, such as the muscles in the case of a fitness enthusiast or bodybuilder recovering from a workout. This is how the concept of ‘guided aminos’ works. This sounds logical in theory, but how does this work in practice? As early as 1990, the Bulgarian national weightlifting team began experimenting with free-form amino acids to find out if they help grow muscles. The research was so successful that part of the study was replicated at the Colorado Springs Olympic Training Center. Since then, many top bodybuilders and powerlifters worldwide have benefited from this new research. There are many misconceptions about muscle contraction and the use of energy substrates during heavy, high-intensity weight training. If you are engaged in repetition strength training (multiple repetitions), you obtain a substantial part of your energy from sources other than carbohydrates. When a muscle contracts, it uses its stores of adenosine triphosphate (ATP, a substance vital for the energy processes of all living cells) during the first few seconds. The mixture that ensures that these stores are replenished immediately is creatine phosphate (CP). The recent explosive increase in the supply of creatine supplements in the market confirms its value for hard-training fitness enthusiasts, bodybuilders, and other strength athletes. Creatine phosphate consists of three amino acids: arginine, methionine, and glycine. To keep the CP and ATP levels high, the levels of these three amino acids in the bloodstream must be increased. Traditionally, these proteins are supplied by food in the diet. Raising the levels of these amino acids or CP with conventional food takes a long time (due to the digestion process) and is not specific, as levels of fats and carbohydrates are also included, which may or may not be desired. Using free-form amino acids, alone or in combination with creatine supplements, can be a guided source of energy for strength and growth.

Amino acids and fat loss

To lose fat, two processes must occur:

• the mobilization and circulation of stored fats in the body must be increased
• fat must be transported and converted into energy at the power centers of the cells: the mitochondria

Several nutrients can help with the conversion of fat into energy, such as lipotropic (fat-burning) substances like choline, inositol, and the essential amino acid methionine, which – in sufficient quantities – can help improve the transport and metabolism of fat. Supplementation with complete essential amino acid mixtures, BCAAs, and glutamine can also help keep calorie and food quantities low while providing direct support to the muscles, liver, and immune system, which is so important for optimizing body composition.

Reducing muscle breakdown

The human body has the innate ability to break down muscle tissue and use it as an energy source during heavy exercise. This muscle breakdown (catabolism) can cause muscle fatigue and loss of muscle mass and can even lead to injuries. This enemy of fitness enthusiasts and bodybuilders is part of a process known as gluconeogenesis, which involves producing or synthesizing glucose from non-carbohydrate sources. The part of this process that is important for the fitness enthusiast and bodybuilder is known as the glucose-alanine cycle. In this cycle, BCAAs are taken from muscle tissue, and pieces of them are converted into the amino acid alanine, which is transported to the liver and converted into glucose. If you supplement with BCAAs, the body does not need to break down muscle tissue to obtain extra energy. A study at the School of Human Biology at the University of Guelph in Ontario, Canada, confirmed that using BCAAs (up to 4 grams) during and after exercise can lead to a significant reduction in muscle tissue breakdown during training. In addition to BCAAs, arginine is another amino acid that is useful for bodybuilders and fitness enthusiasts. Even though it does not have the fantastic effects that were once attributed to it – which spoke of the amino acid’s ability to raise growth hormone levels – new research shows that arginine – in large but safe and affordable doses – can increase growth hormone levels by about 1000%.

Free-form versus di- and tripeptides

The form an amino acid takes has been a confusing subject for many years, partly because there was research showing superior absorption of purified di- and tripeptide fragments. Di- and tripeptides are simply two or three amino acid molecules bonded together, as opposed to the single molecules of free-form amino acids. The fact is, pure free-form amino acids in powder form are very quickly absorbed through the small intestine into the bloodstream, and therefore rapidly available to the tissues. The problem with pure di- and tripeptides is not their biological availability, but their availability to the consumer. Additionally, hydrolyzed proteins such as whey and lactalbumin are not always good sources of di- and tripeptides. Generally, they contain very few of these amino acid combinations, and the little that is present is overshadowed by the large mass of longer-chain peptides that these hydrolyzed proteins contain. So while pure di- and tripeptides are efficient in their ability to be absorbed into the bloodstream, free-form amino acids are just as good or better for bodybuilders and other athletes, and – very importantly – these are available at the nearest health food store.