By Jaclyn Mullick, B.S.

As we all know protein is an important component of our diet that helps to build muscle mass. But how does protein help to peak your performance? How much protein should you be consuming in a day or even a sitting? Also, what kinds of protein are going to benefit your needs the most efficiently? These are all questions I hope to clear up by the end of this article.

It has been said that your body can only metabolize 50 grams of protein in one sitting. While this may be true for some people, it has yet to be scientifically proven. More realistically your body will utilize as much protein as it needs from one sitting. This amount could be more or less depending on what is needed.

The recommended daily intake of protein for an adult athlete is 0.75g per pound of body weight, but depending on your needs can be up to 1.5g per pound of body weight. Say Tom is a 185 pound athlete trying to build muscle mass and you want to know how much protein he should be eating a day. You would simply take your weight (in pounds) and multiply it by 0.90 (value from Table 1) to get 166.5 grams of protein a day. Of course this is the just a recommendation and can vary from person to person depending on your goals and needs.

Table 1: Protein Requirements in Grams per Pound
of Body Weight per Day

The most reliable method of determining protein quality is using the Protein Digestibility-Corrected Amino Acid Score(PDCAAS). PDCAAS was developed by the Food and Agriculture Organization (FAO) to compare the quality of different proteins based on amino acid requirements necessary for humans. A protein receives the highest value (1.0) by containing all the essential amino acids required by our bodies. The idea is that all the protein needs of your body will be met with if your diet provides you with enough of the essential amino acids. It first scores a protein based on its amino acid content and then adjusts it to account for the food's digestibility. "Corrections for digestibility of protein are applied to give a protein-quality rating such that's much closer to reality for human metabolism."(Minser, Bill Ph.D., The Great Animal Versus Vegetable Protein Debate: What is the Best Protein for Muscle Growth? www.hammernutrition.com) The PDCAAS is based on the amino acid needs of children ages 2-5, since this is the group that needs the greatest amount of amino acid consumption. By using a 2-5 year old child's needs as a base, it is assured to exceed the amino acid needs of everyone since your needs decrease as you get older. Table 2 lists the PDCAAS of the protein containing food that I could find.

Table 2: Protein Digestibility-Corrected Amino Acid Score's (PDCAAS) for Specific Foods

*Table adapted from Minser, Bill Ph.D., The Great Animal Versus Vegetable Protein Debate: What is the Best Protein for Muscle Growth? www.hammernutrition.com

If you are looking to peak your performance, you need to be eating more protein with a high PDCASS value. When there is a deficiency in any essential amino acid the rebuilding process becomes less effective. It is for this reason that you need to balance out your proteins. Timing is also important when trying to peak performance. When you workout, protein production decreases and can last for many hours after, during your body's rebuilding phase. In order to help your body repair and rebuild muscle mass, it is important to consume protein, especially BCAA's, within 45 minutes of working out. It is also important to consume protein during this time to help rebuild red blood cells destroyed during heavy exercise.

Protein deficiency can cause growth abnormalities and hinder tissue development. It can lead to tiredness, low energy levels, weakness, lowered resistance to infection and disease, slowed healing of injuries, and prolonged recovery from exercise in athletes. Too much protein over a long period of time can also cause problems. High amounts of protein can be broken down into ammonia in your body. Ammonia is toxic to the body so it gets converted into urea. The increase of urea concentrations places a great strain on your liver and kidneys and can lead to gout and even arthritis.

No matter what your goals are, an efficient intake of protein is an important part of your diet. By balancing your daily intake of proper amounts of protein, carbohydrates and fats one's training performance can reach its peak.

References:

Hatfield, Frederick. Fitness: The Complete Guide. 7th Edition. 2001.
Minser, Bill Ph.D., The Great Animal Versus Vegetable Protein Debate: What is the Best Protein for Muscle Growth? www.hammernutrition.com
Tim's Nutrition and Weightlifting Page, www.sover.net/~timw/fitness.htm

If you have any questions or comments regarding this article, please feel free to contact jaclyn@issaonline.com.