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| "Amino acids for sports" has long been common sense in the world of professional sports. Presently, however, favorable functions of amino acids are gaining attention among all people doing sports, not only athletes. The functions are roughly divided into 3 categories: (1) muscle building, (2) increase of stamina, and (3) recovery from fatigue. |
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| Muscle tissues are comprised of two proteins, actin and myosin. The main components of the two proteins are leucine, isoleucine, and valine, which are called branched chain amino acid (BCAAs) for their molecular structures. BCAAs accounts for about 35% of the essential amino acids contained in myoproteins. Replenishment of BCAAs increases the raw materials for muscle tissues, contributing to muscle building. |
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| When we do strenuous exercise or go running for a long time, the body begins to decompose proteins and consume BCAAs in order to compensate for insufficient energy sources. In fact, the post-competition blood level of BCAAs may be decreased by 20% because of intramuscular BCAAs consumption in hard sports such as marathon and cross-country skiing. This fact shows that strenuous exercise consumes and damages muscle tissues. However, we can reduce muscle damage and inhibit the lowering of muscular strength by replenishing BCAAs timely before or during the sport activity. The sufficiently supplied BCAAs, used as exercise energy, gives room for energy sources, allowing us to maintain our stamina for a long time. Further, if we replenish BCAAs immediately after the sport activity or before going to bed, it would promptly recover the damaged muscles and prevent symptoms such as muscle soreness. |
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| BCAAs also has a function to suppress the production of lactic acid, a fatigue-causing substance. Here is how muscular fatigue occurs: When we continue exercise, the blood level of lactic acid is increased. Thus, the pH in muscles is decreased, causing difficulty in muscle contraction. However, replenishment of BCAAs inhibits the elevation of the blood lactic acid level even during strenuous exercise. Sport performance is influenced more by decreases of willpower and concentration than by muscular fatigue. These decreases are caused by increase of serotonin, a neurotransmitter, in the brain. The raw material for serotonin is tryptophan, an essential amino acid. When we do strenuous exercise for a long time, tryptophan is transferred to the brain, leading to the production of serotonin. When plenty of BCAAs is taken, however, it is difficult for tryptophan to enter the brain, resulting in suppressed production of serotonin. This is how replenishment of BCAAs lightens the lowering of willpower as well as the physical and mental fatigue. |
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| In addition to BCAAs, arginine and glutamine also have positive effects on the body engaged in sport activities. Arginine is closely related to the secretion of growth hormone. Growth hormone is important both for muscle building and for muscle repairing. Replenishment of arginine is considered to promote the synthesis of myoproteins. Glutamine, an amino acid distributed abundantly in muscles, helps the synthesis of myoproteins and inhibits their breakdown, as is the case with leucine. Since continuation of strenuous exercise requires glutamine in many organs, it is important to replenish glutamine when doing sports. |
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