Amino Acids are complex chemicals that are the building blocks of protein, which in turn are required for the creation of new tissue, and the repair of existing cells. An Essential Amino Acid cannot be synthesised or created by the body, and must come from the diet. Whilst a regular diet is enough to supply most people with all the amino acids that they require, anyone involved in heavy training may require a supplement to ensure enough of the various essential amino acids are consumed to meet the body's needs. Essential Amino Acids (EAA's) are required in order to build new tissue and help with cellular repair which takes place when muscles are recovering. Getting the right amount within a diet helps athletes to improve their physique and also recover quicker from exercise. The main essential amino acids required by the body are L Leucine, L Isoleucine, L Valine, L Lysine, L Phenylalanine, L Threonine, L Histidine, L Methionine, L Tryptophan. These can be found in small quantities in natural foods. We require all the different essential amino acids as part of our diet for a number of reasons including cellular repair, but they are also required in order to get the most out of protein rich foods. If you do not get enough essential amino acids in your diet, the body will not extract the maximum nutrients from protein sources, and the calories in the protein will be stored as fat. The requirement for a balanced number of amino acids in the diet is known as 'limiting protein utilisation'. A good supplement will contain essential amino acids in the correct ratios. This will improve their uptake in the body, and provide maximum nutritional benefit. Increasing the intake of essential amino acids will allow athletes to train at a higher intensity for longer thanks to the improved recovery offered by a more balanced diet.