Protein requirements of soccer.

Although the physical demands of soccer have been studied frequently over the years, there has been little attention to the dietary protein needs of soccer players. Recent data from both moderate-intensity, prolonged (endurance) and heavy-resistance (strength) exercise studies indicate that the current recommendations (0.8 g per kg body mass per day) for protein intake are probably suboptimal for individuals who are chronically active. Endurance athletes need more dietary protein than sedentary individuals to maintain an auxiliary fuel source which appears to become increasingly important as exercise is prolonged. Strength athletes can also benefit from a greater protein intake than is currently recommended because it appears that, in combination with heavy-resistance training, it can provide an enhanced stimulus for muscle development. Soccer is a high-intensity, intermittent activity which requires aspects of both strength and endurance over a period of 90 min. As a result, soccer players would be likely to benefit from protein intakes above current recommendations not only because of their potential to enhance strength, but also to provide a supply of amino acids for any increased amino acid oxidation that may occur during training and in competition. Based on the related exercise studies completed to date, it appears that a protein intake of 1.4-1.7 g kg-1 day-1 should be adequate for soccer players. Assuming free access to a wide variety of foods, this protein intake can be easily obtained by most soccer participants. Individuals at greatest risk of falling short of this intake include those who are growing (especially children in developing countries where suboptimal protein intake may be common) or those who consume proteins of lower quality. Although diets high in protein are frequently condemned because of possible kidney problems, it appears these concerns have been over-emphasized. There is no evidence that protein intakes in the range recommended will cause healthy individuals any concerns.