what are proteins used for
Proteins are believed to increase performance in terms of athletics. Amino acids, the building blocks of proteins, are used for building muscle tissue and repairing damaged tissues. Protein is only used as anaerobic fuel when carbohydrates are low, or as aerobic fuel when lipid resources are also low.roteins are essential nutrients for the human body. They are one of the building blocks of body tissue, and can also serve as a fuel source. As a fuel, proteins contain 4 kcal per gram, just like carbohydrates and unlike lipids, which contain 9 kcal per gram.