Protein used to be a substantial part of athletes’ diets because coaches thought it built muscle. It doesn’t—well, not directly. When we eat protein, it is digested into amino acids, which are used to build and repair all types of tissue—muscle, bones, ligaments, tendons— as well as produce needed hormones and enzymes. Although proteins are the building blocks for muscle, you build strength not by eating protein but through resistance training. In a well-balanced athlete’s diet, protein should be about 15 to 20 percent of the calories consumed. Table 16.2 shows the recommended protein intake for athletes. Because protein is not stored in the body, athletes need to consume the needed amount daily. This is easy to do if they eat a well-balanced diet according to the My Plate recommendations. Of course, not all athletes eat a well-balanced diet. Athletes who are trying to lose weight or are on a restricted diet for other reasons need to pay attention to eating enough protein. Also, the foods that are high in protein are often high in fat (e.g., meats or dairy products), and so in an effort to reduce fat in the diet, athletes may also consume inadequate amounts of protein. Athletes who eat a vegetarian diet with no meat, fish, poultry, eggs, or milk must make sure they get enough protein.Beans, rice, corn, corn tortillas, refried beans, peanut butter, and bread are good protein sources for vegans. Athletes can also eat too much protein, which can create serious problems. First, when athletes eat diets high in protein, they are less likely to be eating enough carbohydrate. As we discussed in chapter 14, when muscles cannot obtain energy from fat and carbohydrate, they’ll burn protein for energy. This is undesirable because it uses the protein needed for tissue maintenance. Second, because protein can’t be stored and produces more metabolic waste that must be removed through the urine, the risk of dehydration is greater with a high-protein diet. This is why athletes’ diets should be high in carbohydrate; you don’t want them to deplete this more-efficient burning fuel and begin the destructive process of consuming their own muscle tissue.There’s a booming business in protein supplements, especially among bodybuilders and power athletes. We’ll discuss these supplements later, but in general your athletes will be better off getting their proteins from food rather than from pills.