 By Elena Voropay "The human mind treats a new idea the way the body treats a strange protein; it rejects it."
- Biologist P.B. Medawar
If there is one topic that bodybuilders talk about the most, that would be protein. The one undeniable fact that all lifters agree on seems to them as clear as your bodybuilding goals: no protein – no muscles. But when you take a closer look of what's happening inside your body you will realize that protein has a much more profound function than helping you lift heavier weights or make mountains of lean mass.
Although your body appears quite solid, it is always in a constant state of flux. To quote the Greek philosopher Heraclitus, "You cannot step in the same river twice," meaning that a river may look the same every day, but it never is the same because of the constant flow of new water running through it. This is also true of the human body. All cells and tissues are constantly being turned over - old cells die and new cells replace them. The human body may also look much the same from day to day, but through the process of respiration, digestion, elimination and rebuilding, it is constantly being re-born.
Quantum physicists have proven that 98% of the atoms in your body are replaced within one year. In three months your body produces an entirely new skeleton. Every six weeks, all the cells have been replaced in your liver. You have a new stomach lining every five days. Every month you produce an entirely new skin.
Where do all these new cells come from? The answer of course, is from the foods you consume every day. That's why the saying, "You are what you eat" is literally true from a molecular standpoint. And with that in mind, remember that every food and nutrient has its own purpose. Carbohydrates give immediate energy, fats provide long-term reserve, but the main construction material for all cells and tissues is protein. Proteins provide the nuts and bolts of the cell, all the machinery, and most of the structure.All cells in your system are made up of this powerful chemical.
Brain cells, for example, are 10 percent protein. Muscle and red blood cells have as much as 20 percent. Overall, protein is the second largest building material of the human body (preceded only by water) comprising approximately 15 per cent of your total body weight. Most of a cell's volume is water – roughly 70 per cent – but of the remaining space, 40 to 80 per cent is protein. In other words, if you were to completely dehydrate your lean muscular system, you would come up with around 70-80 per cent of protein comprising your dry body mass. Most importantly for you, the athlete, the proteins in your muscles are continually turned over as muscle is broken down and new tissue is synthesized.
Its not surprising that bodybuilders put so much emphasis on protein. You use and recycle all the proteins continuously in the process of metabolism. The manufacture of proteins is the most energy-expensive process going on within the body. When you are resting, about one-fifth of our energy is being expended on protein synthesis, even though all that protein is continuously broken down over and over again. During growth, such as seen in babies and growing children, protein synthesis consumes more energy – about half of all fuel produced is used for protein synthesis.
What is the function of protein?
The proteins synthesized by the body perform a variety of important physiological functions. Protein is used as a building and repair material for tissues and organs, such as skin, hair, muscles, liver and in the formation of hormones, enzymes and antibodies.
- Protein maintains the strength and integrity of muscles, connective tissues (ligaments and tendons), hair, skin, and nails through the production and maintenance of structural proteins, such as collagen, elastin, and keratin. Contractile proteins are involved in muscle contraction and movement. Examples include myosin and actin found in the muscles.
- Protein helps regulate production of enzymes. All the chemical reactions in the body are catalyzed by compounds known as enzymes which are made from protein. They are often referred to as catalysts because they speed up chemical reactions. Examples include the enzymes lactase and pepsin. Lactase breaks down the sugar lactose found in milk. Pepsin is a digestive enzyme that works in the stomach to break down proteins in food.
- Hormones are often described as the bodies chemical messengers that travel throughout hte body delivering instructions to our living cells. Examples of hormones that are proteins include:
- insulin (increases the transport of nutrients fueling all cells in the body and moves glucose into cells lowering blood glucose levels)
- growth hormone (promotes growth of all body tissues, including your muscles, ligaments, tendons, bones, hair and skin)
- glucagon (increases blood glucose levels, especially important during exercise and when there is shortage of nutrients)
- thyroxin (regulates your metabolic rate, or the conversion of eaten fuel from food into usable energy)
- calcitonin (regulates serum calcium concentrations, importantly in calcium and phosphorus metabolism and the integrity of bones, teeth and hormonal production)
- oxytocin (stimulates contractions in females during childbirth)
- Protein is used in the production and transport of various amino acids and lipoproteins. A dozen different types of “motor” proteins are known, which drive along the different fibres carrying different loads, such as other proteins or mitochondria. Certain transport proteins, such as hemoglobin (carries oxygen), transferrin (carries iron), ceruloplasmin (carries copper), retinol-binding protein (carries vitamin A), albumin and transthyretin serve as a helping aid in carrying other proteins to the needed cells where they can perform their main functions. Some proteins move molecules in and out of cells working as 'pumps'.
A very important example is the sodium-potassium pump which regulates the concentrations of sodium and potassium in the body fluids, maintains the function of nerves and muscles and makes all muscular contractions possible. Proteins are also part of lipoproteins which, among other duties, participate in the transportation of fat and cholesterol.
- Protein maintains nitrogen balance. Of the four energy nutrients - carbohydrates, protein, fat and alcohol - only protein contains nitrogen, which is critical in repairing, rebuilding, growing muscle tissue, fighting infections, handling stress and staying healthy. Nitrogen is constantly depleted in sweat, urine and feces, making it necessary to ingest enough protein to keep the body in a state of positive nitrogen balance. The maintenance of this crucial equilibrium is the foundation of many nutritionally sound, doctor-prescribed lifestyle diets for many different conditions.
- Protein is also essential in keeping your immune system strong, repairing, building and preventing cell damage, reducing fatigue and boosting energy levels. It is used in the production of antibodies which play an important role in the immune system by attaching to antigens (viruses, bacteria, or other foreign invaders). Proteins make these foreign harmful agents more visible to the immune cells (called macrophages) and empower them to concour and destroy the invaders.
Amazingly, the body's cells retain a molecular memory of the antibodies used in an invasion, to be used the next time that infection sets in. Thus, once protein helps the body fight off disease the first time, it continues to thwart that condition in the future.
- Protein helps monitor water balance, regulate fluid volume and even the composition of body fluids. Since your body is made mostly of water with the majority found between and within cells as well as inside the vascular system (i.e., capillaries, veins and arteries), you need protein to keep your system in ultimate balance. Proteins are are attracted to water, meaning they are hydrophilic and exert osmotic pressure which is an integral part of maintaining proper fluid balance.
Without enough protein to attach to water in the vascular spaces, the water leaks out into the spaces between the cells, causing edema, or water retention, due to the kidney's inability to excrete it. Disturbed mineral and electolyte balance may have devastating consequences.
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