## 4 Importance of Protein and Amino Acid Supplements  
Protein's value for athletes and combat players has long been established. Protein has always been regarded as a critical nutritional element for athletic achievement, from Olympian coaches in ancient Greece to today's multi-millionaire sportsmen [137]. The nature of that relevance has been a source of contention for an equal amount of time. Protein and amino acid consumption is deemed vital to effectiveness by many athletes, particularly strength and team sports competitors. Supplements containing amino acids and proteins have grown into a multibillion-dollar industry. Proteins are demonstrated to have a synergic effect with resistance training on muscle synthesis. The recommended dose varies from 0.8 g/kg to 2g/kg depending on age, gender and body composition and can be increased up to 3 g/kg when body composition enhancement is targeted. In combat sports, these facts have important applicability in each training cycle, from the accumulation phase, where strength and muscle synthesis are targeted, to the intensification phase, where speed and tactics are exercised. In the precompetition and RWL periods, adequate protein intake is essential, as it is proven to limit muscle loss, thus sustaining the best possible body composition [44]. Nutrition science went even further and identified key amino acids that promote muscle synthesis, offering targeted supplements so that athletes can benefit without any unwanted additional calories. The amino acid content for muscle protein balance tends to be influenced by resistance training. Only necessary amino acids are required for net muscle protein synthesis [138]. As a result, non-essential amino acids are not required for the activation of muscle protein synthesis that results in net muscle protein. Even single amino acids have been shown to increase protein synthesis and potentially net muscle protein synthesis. [PERSON] et al. 1999 [139] found that ingesting leucine after exercising stimulates protein translation initiation mechanisms, resulting in enhanced muscle protein synthesis. Bolus dosages of single essential, but not non-essential, amino acids increased muscle protein synthesis in sedentary individuals. Individual amino acids may therefore serve as a stimulus for muscle protein synthesis and promote a positive net muscle protein balance. These findings imply that essential amino acids may increase muscle protein synthesis in two ways: (1) by providing a substrate for it and (2) by serving as a regulatory factor [67]. Acute stimulation of muscle protein synthesis and net muscle protein synthesis apparently requires small amounts of essential amino acids. Ingesting as little as 6 g of essential amino acids, both with and without carbohydrates, leads to substantial increasesin muscle protein synthesis, resulting in net muscle protein synthesis. Furthermore, some evidence suggests that the response of muscle protein synthesis to essential amino acid consumption after exercise is dosage-dependent. The reaction of net muscle protein balance to two doses of 6 g of essential amino acids each was nearly double that of two doses of 6 g of miscellaneous amino acids each [140]. Each dose of combined amino acids had around 3 g of essential amino acids, which was nearly half of the quantity in the two 6 g doses. As a result, there may be a saturation point for critical amino acids over which no further stimulation is conceivable. The fact that net muscle protein synthesis was identical regardless of whether 20 g or 40 g of essential amino acids was consumed after resistance exercise offers credence to this theory [141]. The supply of intracellular amino acids may influence muscle protein synthesis and net muscle protein balance in reaction to hyperaminoacidemia. Hyperaminoacidemia is caused by the ingestion of a nutrient that enhances amino acid supply to the muscle, transit into the muscle cell and intracellular amino acid accessibility.