According to Francis Nettl, MD, former director of sports and rehabilitation medicine for the US Navy, “A highly biologically active protein source is significantly more likely to prevent a catabolic state due to its superior absorption and retention properties” (1). Whether you’re a professional bodybuilder, or want to become one, or just your average Joe or Jane poring over vast amounts of information trying to decide whether you need to add protein to boost your training regimen, Dr. Nettle puts the problem in a nutshell.
The question of whether large amounts of dietary protein are needed to optimize protein synthesis and enhance muscle hypertrophy and strength has been debated for over 100 years, a debate fueled by unusual claims and the large number of proprietary brands of protein products available. To add fuel to the fire, when you go to your local gym, health club or health food store, you won’t get straight answers. If you look past the advertising – and in some cases, scientific jargon – it will be easier to unravel the mystery surrounding protein supplements and how to choose the most effective products. You just need to be armed with a little more information.
Protein 101
Proteins are the basic building blocks of life, the main structural components of the body. Dietary proteins are too large to be absorbed through the intestines, so during the digestion process they are broken down into smaller components called amino acids. Smaller agents are able to penetrate the intestinal wall, they are absorbed into the bloodstream, they are then recombined and used to build and maintain body structures. Amino acids not used for this purpose are used for energy. There are currently 22 known amino acids, eight of which are considered essential in the sense that the body cannot produce them on its own, so they must be supplemented with food. The remaining 14, known as non-essential amino acids, are produced in your body. The accompanying table lists all amino acids.
When you look in the mirror, you see a protein in action. Your hair, eyes, skin, bones, heart, veins, muscles and the genes that define your individual blueprint are made of protein. While other nutritional factors are important, it is actually protein that builds your muscles. Only protein provides your muscles with the nitrogen they need to grow, heal and repair. Nothing gives you more nitrogen than protein, neither carbohydrates, nor anti-catabolic substances – substances that slow down the breakdown of muscle protein – fats or creatine and HMB (2).
Although there is a clear distinction between essential and non-essential amino acids, the term “essential” is a bit of a misnomer, since you need them all to grow bigger. In fact, when any proteins are synthesized, all amino acids must be present at the same time. (3)
Amino Acid Pool
Modern science suggests that proper meal planning is important and that by eating frequently – at least 6 times a day – athletes can limit muscle protein breakdown. In studying nitrogen retention and the absorption of amino acids into the bloodstream, scientists have discovered that your body lives and breathes to maintain what is called a free amino acid pool, which can be described as a small reservoir of amino acids that helps repair and rebuild muscle tissue. However, if you do not ingest adequate amounts of protein, the amino acid reservoir begins to be used up. The body begins to look for some way to refill the reservoir and, to maintain the correct ratio, breaks down existing muscle tissue.
The real problem is that the pool of free amino acids must be replenished about six times a day. (1)
In fact, about 75% of the amino acids in a normal adult are metabolized to create tissue proteins, enzymes, and protein hormones. Due to the constant breakdown of body proteins, new proteins are required. Most amino acids that were not used in protein synthesis are converted into the necessary non-protein nitrogen components of the tissue. In fact, protein itself is 15% nitrogen. Your body constantly releases nitrogen through excretion and through your hair, skin and nails. If there is not enough intake and retention, you are at risk of nitrogen deficiency. (4)
Protein Principle 1:
Since protein provides nitrogen for growth, you must maintain an adequate supply throughout the day.
Protein Arithmetic
Given the importance of getting enough protein, the burning question for 100 years has been how much is enough? The current recommendation is 0.8 grams of protein per kilogram of body weight per day (5). For example, a woman weighing 130 pounds needs 47 grams of protein. To get this quantity, convert pounds to kilograms using the factor 2.2, then:
130 pounds: 2.2 = 59 kg
59×0.8 g = 47 g
Many researchers argue that the above requirements are based on normal growth and recovery and are insufficient for bodybuilding. In recent years, research has confirmed that people who engage in heavy resistance training require more protein than the above recommendations to maintain nitrogen balance and stimulate muscle development. Current evidence suggests that 1.7 to 1.8 grams of protein per kilogram of body weight is a more realistic figure, as shown in the following example. An example is given of a 220 lb man who does strength and resistance training and eats 6 times a day. Insert your own weight to determine your intake level.
Step 1 : Convert pounds to kilograms:
220 pounds: 2.2 = 100 kilograms
Step 2: Multiply weight in kilograms by 1.7 and 1.8:
100 x 1.7 = 170 grams of protein per day
100 x 1.8 = 180 grams of protein per day
Step 3. Now calculate how much protein you need to consume during the day, in this case for 6 meals:
170:6 = 28.3 grams of protein per meal.
Caution: There are conflicting reports that protein intake at the levels described above poses some degree of risk. Medical officials advocate that excessive amounts of protein and/or amino acids, not accompanied by proper electrolyte balance, meaning dissolved minerals in the bloodstream, saturate the body with harmful waste products; this is a situation caused by incomplete conversion of protein into amino acids. As a result, the body produces uric acid, a toxic byproduct, instead of muscle tissue (6). It may be wise to include a liquid colloidal mineral formula in your regimen in addition to drinking plenty of water.
You are what you take in.
According to Dr. Barry Sears, author of ENTER THE ZONE, if your body is consistently deprived of essential amino acids, the rate at which new protein is formed will slow down. He also states that the amount of amino acids that actually enter the bloodstream is primarily determined by the digestibility of the protein source (7). This is due to the fact that digestive enzymes are unable to penetrate the protein, the undigested portion will pass through your system without being absorbed and used by the body. Moreover, given the natural daily fluctuations in amino acid levels in the bloodstream, the content of your food can have a major impact on how well these powerful substances get to their end points, namely muscle cells (8).
Protein principle 2:
There is an established concept that advocates including some carbohydrate in your post-workout meal, which helps speed up the rate at which amino acids are transported toward muscle cells (9). Current evidence suggests that 200 calories of carbohydrates will raise your insulin levels just enough to promote the transport of amino acids into muscle cells (1).
Protein Values
The final piece of the puzzle is choosing a protein that is highly biologically active, meaning it will give up the most nitrogen. The researchers developed a formula that determines the protein quality of a food that has biologically active value, or BV, according to what is called the digestibility of amino acids, or PDCAAS.
If the availability of amino acids in food meets the requirements of your body, then the level of protein utilization will be 100%. Biological value then refers to the percentage of dietary protein utilized by the body. Proteins are also classified according to their sources, such as animal, plant and dairy sources. The old method of determining protein quality and nitrogen retention capacity, which was known as protein efficiency ratio, or PER, has been replaced by the more modern PDCAAS.
The PER method involved a carefully controlled animal feeding test that calculated the amount of weight gained for each gram of protein consumed. Casein, a milk protein, was used as a standard. PDCAAS, which is a method recently recognized by the Food and Drug Administration, is based on the content of essential amino acids in food and the ratio of these amino acids to each other. Scientists now have technology to take the guesswork out of determining the ability of individual proteins to store nitrogen in muscle. While the old method measured growth relative to protein intake in rats, the biological value involves measuring nitrogen from dietary protein and nitrogen excretion in human feces and urine. So this method focuses on how well nitrogen is retained after you consume each individual source of protein.
Here is the current biological value of a group of proteins commonly consumed by bodybuilders:
Whey Protein Isolate 159
Whey Protein Concentrate 104
Egg White 88
Chicken 79
Casein 77
Protein Principle 3:
The biological value and digestibility of protein are critical factors in its relationship to absorption, nitrogen retention, retention and any subsequent muscle growth (10).
Quick tutorial
The next time you buy protein products, use the following guidelines to ensure you don’t end up with a poorly formulated product – even though the protein source is considered to have a high level of biological value. Read what is printed below and always keep the following keywords in mind.
1) Acid hydrolysis. These proteins have already been broken down, but are processed in an acidic environment rather than under the influence of enzymes. They often contain sodium, so they promote water retention.
2) Cross-filtered ion exchange (CFIF). This protein produces more results than protein subjected to only one ion exchange method. Cross filtration recovers 98% of the denatured protein, while ion exchange recovers 90.8%.
3) Technique of ionized cross filtration, or microfiltration. This process does not require high temperatures to process the protein, which preserves glutamine, the most abundant amino acid in bone tissue. In fact, glutamine makes up about 61% of all bone amino acids.
4) Denatured. It occurs when a protein is exposed to high temperatures – usually over 60 degrees Celsius – or to chemicals that break down certain chains on which some protein structures are based. When this happens, the protein can no longer perform its biological function (12). Look for undenatured types of protein.
5) Enzymatic hydrolysis. It creates semi-digested proteins, which also includes breaking them down into smaller peptides such as di-, tri- and poly-peptides. Peptides do not bind water in the intestines, which causes diarrhea, as some amino acids often do.
6) Unmodified proteins. They remain in their original natural form and require complete digestion.
7) Isolated amino acids. These individual amino acids require no absorption and do not contain any animal by-products.
Protein isolates. These are smaller protein fragments, just like semi-digested proteins.
9) Pure crystalline amino acids. They do not require digestion.
When you look in the mirror. You see protein in action. Your hair, eyes, skin, bones, heart, veins, muscles and the genes that define your individual blueprint are made of protein.
