The primary role of protein in the body is to support the growth, maintenance and repair of muscle tissues. In addition, protein is a part of many of the enzyme and hormone functions within the body. Protein can be used as a fuel source after it is converted to carbohydrate through a process called gluconeogenesis. during the later stages of training or racing when glycogen stores become depleted, the body can supply up to 15% of its energy from the breakdown of body protein. Athletes must be properly fueled before and during training in order to prevent the body from breaking down protein for fuel.

The body does not store excess dietary protein as protein. once dietary protein has fulfilled its growth and repair function, it is either converted to carbohydrate and used for energy or converted and stored as body fat.

Unlike dietary carbohydrate, dietary protein has yet to be established as a performance enhancing nutrient. Protein may have a more indirect impact on performance as current research suggests that it may actually help the recovery process when consumed with a carbohydrate source post-workout. in addition, some research suggests that the addition of protein to a carbohydrate based sports drink during training may decrease muscle damage and enhance performance. it should be noted that there is major debate as to whether or not protein is truly beneficial in sports drinks as many credible sports nutrition professionals view the supporting scientific studies as flawed.

Daily Protein Requirements


An athlete’s protein needs are based on lean body weight, activity level and overall caloric intake. These needs can fluctuate depending on the athlete’s periodization phase. Most sports nutrition texts suggest that 10-20% of an athlete’s calories come from protein. An athlete’s protein needs can be easily met through diet as well as some of the sports bars on the market. The use of supplemental protein powders or drinks (whey or soy) may be utilized to help some vegetarian athletes meet their needs (Table 6.3).

Athletes can meet their protein needs through diet alone. Protein needs can be met with animal sources including red meat, chicken, fish, eggs, cheese and dairy, but they can also be easily achieved with adequate amounts of grains, beans, peas, soy, nuts and vegetables. A practical way to help athletes understand how much protein they need is to implement the palm method. The size of their palm (diameter and thickness) can be used as a guide to a reasonable protein portion. Athletes should know that 1 oz meat, 8 oz milk, 1 large egg or ¼ cup cottage cheese all provide 7 grams of protein.