Proteins
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Proteins |
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During the process of digestion the proteins in our food are broken down into their constituent amino acids which are in turn absorbed by the blood capillaries and transported to the liver. The amino acids are then synthesized into proteins or stored as fat or glycogen for energy. Each gram of protein produces approximately 4 kcal. Many proteins function as enzymes and others:
Amino acids are the building blocks of protein. The formation of protein can result in dehydration because water molecules are lost as amino acids combine to form more complex molecules.
The body requires 20 different amino acids of which 8 are referred to as essential amino acids which cannot be synthesized by the human body. Animals and plants manufacture proteins which contain these essential amino acids. Non-essential amino acids can be synthesized by body but this does not mean they are unimportant, they are, it is just that the body is capable of producing sufficient to meet the demands for growth and tissue repair. It is therefore important that are diet contains appropriate levels of protein.
The essential Amino Acids are: lsoleucine, Leucine, Lysine, Methionine, Phenylaianine, Threonine, Tryptophan and Valine.
The non-essential Amino Acids are: Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Clutamic acid, Clutamine, Glycine, Histidine*, Proline, Serine and Tyrosine.
* Histidine is essential for babies but not for adults.
Despite the beliefs of many coaches and athletes, eating excessive protein provides little benefit. For athletes, muscle mass does not increase simply by eating high protein foods. Protein intake significantly above the recommended values can prove harmful because excessive protein breakdown strains the liver and kidney functions through the production and elimination of urea and other solutes.
The recommended daily allowance for men and women:
Research suggests that protein breakdown increases during and immediately after exercise, and that protein manufacture slows down at the same time. The more intense the exercise, the greater your protein breakdown will be, and the greater your needs will become. If you train to increase muscle mass, your protein needs will be greater still. Extra protein will be needed not only to compensate for protein breakdown but also for new protein to be made and for muscle growth. It is important to realise that a high-protein diet alone will not lead to any increase in strength or muscle size. It is only when it is combined with heavy resistance exercise that additional protein can cause this to happen.
Proteins that contain all the essential amino acids in approximately the right proportions for your body's requirements are sometimes called 'high-biological-value' proteins. These are found in foods that are derived from animals: meat, fish, eggs, milk and dairy products
The following Sports Coach pages should be read in conjunction with this page:
The following web sites contain more information on this topic:
The following journals and books contain more information on this topic:
If you would like any further details or help on this topic then please email me.
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