Proteins

What is protein?

Protein is one of the three macronutrients that make up our diet. In the body, protein - or more precisely, the amino acids that make up each protein - serves as a building block for various types of tissues in the body, which include the internal organs and muscle tissue, as well as countless enzymes and other components of the human body. Without an adequate protein intake, it is not possible to build muscle mass, and insufficient protein intake can even lead to a breakdown of existing muscle substance.

Proteins (Greek: protos = the first, the most important) or proteins (German term) are among the most important basic building blocks of all animal and plant cells. Without them, life would not be possible, since only protein can build cells and repair tissue. As enzymes and as hormones, they regulate the entire metabolism, and as contractile elements (muscle fibers) they enable movement processes. The defense bodies of the immune system and certain transport proteins in the blood also consist of proteins. Under normal conditions, proteins do not play a significant role in energy metabolism, but they are all the more important in building metabolism. Proteins are the main building material of muscles. The actin and myosin filaments (myofibrils) of the muscles consist of protein complexes.

Muscle consists of 20% protein and over 70% water. After all, about 20% of the body weight is protein. However, of the more than 200 amino acids known, humans can only form all the proteins they need from 22 amino acids. A distinction is made between essential and non-essential amino acids. The essential amino acids cannot be produced by the body itself and must therefore be ingested daily with food. The semi-essential amino acids, on the other hand, cannot be produced by the body in sufficient quantities under certain metabolic conditions. The remaining non-essential amino acids can be synthesized by the body from the other (essential) amino acids.

Similar to carbohydrates, proteins are also divided into oligopeptides (2-9 AS=amino acids), polypeptides (10-100 AS) and proteins (more than 100 AS) depending on the number of amino acids. Due to the unimaginably large number of 10130 linkage possibilities, the different proteins can be constructed. Apart from the amino acid sequence (primary structure), the specificity of the proteins is determined by the different spatial structure of the peptide chain (secondary and tertiary structure: folded sheet structure and a -helix structure). The quaternary structure describes the assembly and arrangement of multiple, spatially ordered peptide chains into a biologically active unit. The spatial arrangement and the amino acid sequence are decisive for the biological functions of the proteins.

How much protein do you need and when is there an increased need for protein?

A daily protein intake of about 0.8-1g/kg body weight is recommended, which corresponds to a protein share of the daily nutrient amount of about 12- 15%. Pregnant women and nursing mothers require more protein, and top athletes even consume protein amounts of up to 2.5 g/kg body weight. Children and adolescents also have a higher protein requirement (1-1.2g/kg body weight), although the requirement decreases steadily from infancy onwards. From the age of 25, the human body increasingly loses tissue substance and thus also protein, so that the protein stock decreases by about 20% by the age of 60.

Daily protein requirements depend primarily on the level and type of physical activity. The basic requirement set by different health organizations for:

• Physically inactive people is 0.8 grams of protein per kilogram of body weight.
• Physically hard-working people and athletes have a significantly higher protein requirement, with strength athletes needing the most protein at 1.5 to as much as 2.5 grams of protein per kilogram of body weight, as additional protein is needed for regeneration and building muscle mass.

During a diet with severely restricted calorie intake, an even higher daily protein intake may be necessary to prevent diet-induced muscle loss.

Importance of proteins for the athlete

The protein stockis subject to constant build-up, breakdown and remodeling. Under normal circumstances, there is a dynamic balance between the build-up (anabolism) and breakdown (catabolism) of protein structures in the organism. "Due to the constant building up and breaking down of proteins, there is an amino acid reserve of 600-700 g in the intermediary metabolism, which is called the amino acid pool. This is the organism's only protein reserve, albeit quite dynamic, that it has constantly available."

Since the body, unlike carbohydrates and fats, does not have a direct energy store of proteins, it must constantly absorb them with food so that muscle proteins are not broken down during catabolic processes. During physical exertion in sports, especially in weight training, proteins are initially broken down in the body.

Therefore, it is especially important for athletes that always enough amino acids are made available to the body through protein in the diet. It should be taken into account, on the one hand, that proteins are not stored in the body for long and, on the other hand, that the body can only utilize up to 40 g of protein at a time. "The proper interval between protein food (concentrate or low-fat meal) and exercise should be something like 1 to 1 ½ hours."

The daily protein intake recommendation for an adult is approximately 1 g per kg body weight. The protein requirement of the athlete is generally set higher and can vary depending on the sport. According to recent studies, it is known that protein can account for 5-15% of energy expenditure during prolonged exercise. Another reason for the increased protein requirement in sports is that there should be a sufficient supply of free amino acids in the amino acid pool so that amino acids from skeletal muscles do not have to be used for energy production.

In the context of performance enhancement, the branched-chain essential amino acids play a special role, which is discussed in detail in the topic "Performance enhancement through amino acids". An athlete's requirement is also increased because - especially during high-intensity endurance exercise - there is wear and tear on muscle fibers, structural changes to cell membranes and mitochondria, and inactivation of enzymes and hormones.

Reasons for increased protein requirements of the athlete:

• Additional requirements for new muscle formation (build-up training)
• Increased maintenance requirement for the larger muscle mass (attrition rate).
• Increased wear and tear on functional proteins and other nitrogen compounds
• Possible stimulation effect on protein synthesis.
• The pool of free amino acids in the tissues is an additional energy store and a protection against the degradation of body protein

What are the benefits of protein in powder form?

Especially for people with a high protein requirement, it can be difficult to meet their daily protein needs through whole foods. This is even more true the less time there is to cook and prepare food. This is where protein shakes can provide a convenient and practical alternative that can be quickly prepared and quickly consumed. Furthermore, by choosing your protein powder, you can target the protein sources that are best for your momentary situation. Since the shaker can easily fit in any sports bag, Whey protein powder, for example, is ideal to provide the body with protein directly after training.

The advantages that protein concentrates offer the athlete are obvious: with their use, the athlete can easily increase the amount of protein in his diet without also adding fat, cholesterol or purines, which would be difficult to do with conventional protein sources such as meat, fish, eggs, and dairy products. In addition, a pre-made protein drink can be taken anywhere, so athletes can easily maintain their high-protein diet even when away from home. It is also more cost effective to meet protein needs with protein supplements. Another advantage that a continuous protein supply offers the athlete is a constant blood sugar level, which avoids cravings, which is very helpful especially in dieting. It is advisable to distribute the protein intake sensibly throughout the day. Especially before going to bed and early in the morning protein should be supplied to counteract the nocturnal, catabolic phase.

What are the different types of protein supplements available and which protein is best for which situation?

In our store you can find a variety of different types of protein powder supplements with different compositions for different applications. The most commonly used protein supplements are so-called fast-digesting protein sources, which include.

• Whey Protein,
• Whey Protein Isolate,
• Whey Protein Hydrolysate,
• Egg protein and
• Soy protein include.

These types of protein are digested very quickly by the body and quickly provide the muscles with large amounts of amino acids needed for regeneration and muscle building. Fast digesting protein supplements are particularly suitable for use before and after training, but are also an ideal source of protein for any other time of day.

In addition to this, there are slower digesting protein supplements, such as:

• Casein Protein,
• Beef Protein,
• Peas protein or
• contain a mixture of different protein sources (so-called multi-component protein powders).

These protein products provide the body with amino acids over a longer period of time. These protein powders are best used as snacks and before going to bed.

Increasingly popular are protein supplements that contain proteins from plant sources, such as:

• Rice Protein,
• Hemp Protein,
• Peas protein and
• Soy Protein.

These products are particularly well suited for vegetarians and vegans, although more and more non-vegetarians are also turning to them, as they are free of lactose and some other ingredients that can cause intolerances.

Summary biological functions of proteins

• Building blocks of the musculature and serve to build up vision, ligaments, nerve and connective tissue
• Regeneration and recovery in case of tissue injuries and micro-injuries of the musculature after training.
• as defense substances: antibodies repel invading pathogens
• as enzymes: participation in metabolism
• as hormones: messenger substances that cause a certain reaction at a specific site of action
• Transport functions: especially the blood proteins.

The chromoprotein hemoglobin is responsible for gas transport (O2 transport). Furthermore, foreign substances (active ingredients from drugs) are also attached to proteins and transported in this way.

• Protective and supporting functions: form sheaths around cells (protective colloids), the fibrous protein collagen gives tensile strength to bone and tissue
• are part of the biological membranes
• Energy supplier for energy metabolism, can reformulate carbohydrates; have an increasing effect on energy metabolism
• Transmits hereditary information: the hereditary information carrier DNA (deoxyribonucleic acid) is a protein nucleotide

Function in the body

Proteins occur in the human organism as a component of:

• Hormones (peptide or proteohormones)
• Enzymes
• membrane proteins of the cell wall (e.g. receptors or transport proteins)
• Supporting and scaffolding proteins (e.g. collagen, keratin or elastin)
• Contractile proteins (e.g. actin and myosin filaments as contractile elements of the muscle).
• Transport proteins (e.g., hemoglobin, myoglobin, and certain plasma proteins).
• Blood clotting factors
• Antibodies
• For energy supply only reserve function

Proteins are not as energy-rich as fats. Their energy density is 17.2 kJ/g (= 4.1 kcal/g). The proteins ingested with food are broken down into their building blocks in the intestine, and the amino acids are absorbed to then serve as material for building the body's own proteins. The body uses protein as an energy source only after it has used up its carbohydrate and fat stores. This happens during longer periods of starvation. In a complicated chemical process, glucose can be produced in the liver from some amino acids as an energy supplier. Other amino acids, like fatty acids, can be broken down into so-called ketone bodies, which are metabolized by the organs as an alternative to glucose in times of shortage.

Protein deficiency

Protein has a large number of tasks in our body. A deficiency would have dire consequences:

• Hair loss (hair consists of 97-100% proteins - keratin).
• Lack of drive
• In the worst case, the protein deficiency disease kwashiorkor develops. People (mostly children) suffering from Kwashiorkor can be recognized by their fat bellies. The organism tries to cover the protein deficiency by water, so that the water is deposited in the body after some time (edema).

Other symptoms include:

• Muscle weakness
• Growth disorders
• Fatty liver
• Edema

Biological value (BW)

The biological value of food proteins indicates how many grams of body protein can be built up by 100 g of the food protein in question. At the same time, it indicates how valuable the protein of a particular food or protein concentrate is for building up muscles and other endogenous proteins (e.g. enzymes, hormones). The whole egg protein serves as a reference value, because it has been given a biological value of 100. All other proteins are set in relation to it. The higher the biological value of a food protein, the less the human body needs of it to maintain its protein balance. Animal protein can, in principle, be considered of higher quality than vegetable protein. However, a suitable mixture of animal and vegetable protein sources can achieve much higher biological values than animal protein alone, since the proteins of different foods can complement and enhance each other in their amino acid spectrum. Decisive for the suitability of a food protein for the biosynthesis of body protein is above all the content of essential amino acids and the availability of amino acids. When selecting foods, however, one should not only pay attention to the biological value, but also bear in mind that a large amount of undesirable accompanying substances are taken in at the same time with animal dietary protein, namely purines, cholesterol and fats. Purines in meat provide uric acid as an end product in metabolism, which can be deposited in the kidneys, joints and tendons, resulting in kidney stones, gout and increased susceptibility to injury. In contrast, eggs, milk and dairy products are purine-free. Considering these facts, one should limit the intake of animal proteins and include plant foods in the increased ones. The following table shows how the combination of animal and plant protein sources can even enhance the biological value of protein.

Buy protein: Separating the wheat from the chaff

In some cases, there are major differences in the quality of protein powders. As with "normal" foods, care should be taken to ensure that the list of ingredients is relatively short. Artificial colors and preservatives are often included. High-quality products do without these.

Of course, the origin of the raw materials is decisive for the quality of the product. If the raw materials come from Germany, for example, this speaks for high-quality raw materials because of strict guidelines and hygiene regulations in German production facilities. If a supplement manufacturer does not shy away from the cost of these high-quality raw materials, he usually also advertises it.

Ultimately, the protein content in the protein powder itself is also a quality feature. A protein content of at least 75g per 100g of protein powder is considered a high-quality product. For example, the 100% Dairy Whey Protein from GN Laboratories has a protein content of 80g per 100g.

Which protein to buy?

There are many different types of protein powders, so that you quickly lose the overview as a layman. The different protein sources bring individual properties and can therefore be used and combined in many ways. The amino acid profile of a product should be closely examined, since each protein source has a different. Basically, a balanced amino acid profile is recommended. By combining different protein sources, a deficiency can be excluded. Apart from amino acid profile, different protein sources also have different properties regarding digestion.

*avoid sodium caseinate

References

1. LemonPW (1996) Is increased dietary protein necessary or beneficial for individuals with a physically active lifestyle? Nutr Rev 54(4 Pt 2): 169-75.
2. Arndt K. (HG.) (2001) Handbuch Nahrungsergänzungen-Bedeutung und Anwendung leistungssteigernder Substanzen für Bodybuilding und Kraftsport. Pages: 210-212
3. GEISS/HAMM,Handbook of Sports Nutrition (1992)
4. KONOPKA, Sports Nutrition (1996)
5. BREITENSTEIN/HAMM, Bodybuilding, natural, healthy, successful