A limiting factor for increasing muscle mass is calories, not protein. Therefore, athletes who are trying to increase muscle mass should meet their caloric needs first, by getting enough carbohydrate foods.
Food labels show carbohydrate content.
High carbohydrate foods are those with starch or sugar. Fruit juices, milk and yogurt contain food sugars. Starchy foods are fresh fruits, rice, grains, pasta, breads, cereals and vegetables, including peas, corn, dried beans and potatoes. Athletes require about the same amount of dietary protein as non-athletes or a little bit more. The usual diets of most athletes provide enough protein to cover the increased amounts that may be needed during the competitive season.