Whether you are an elite athlete or an active adult, there is a need to maintain and build lean muscle mass. Muscle mass improves the metabolic rate, reduces body fat and improves functional ability. There are two components that are needed in order to improve your lean body: 1- exercise (correct resistance training) and 2- proper protein consumption. There is plenty research today that states that it is not just the QUANTITY of protein but also the quality,and timing of protein consumption.
HOW TO ASSESS QUALITY?
Protein quality is assessed in a variety of ways: BIOLOGICAL VALUE – BV chart (based on nitrogen uptake vs nitrogen excretion) determines how quickly the body can USE the protein absorbed. Another measurement is the PROTEIN EFFECIENCY RATIO- PER (based on measurement of growth in animals: lab rats are fed protein and growth is measured and compared to a standard). There is also NET PROTEIN UTILIZATION – NPU is similar to the biological value but also takes into account the nitrogen absorption.
Here are standard values of protein from these assessments:
| Protein | PER | BV | NPU |
| Whey | 3.2 | 104 | 92 |
| Egg | 3.9 | 100 | 94 |
| Milk | 2.5 | 91 | 82 |
| Beef | 2.9 | 80 | 73 |
| Soy | 2.2 | 74 | 61 |
| Casein | 2.5 | 77 | 76 |
Studies also target certain amino acids to see their potential for protein synthesis. Based on these studies: protein synthesis has a “tipping point” where muscle protein synthesis will occur, suggesting that 2.5g of the amino acid leucine must be present. Thus % of leucine in total protein is a another measurement of protein quality as it relates to muscle recovery.
| Protein | % Leucine | in order to reach 2.5g |
| Whey | 12% | 21g scoop |
| Egg | 8.60% | 5 eggs |
| Milk | 9.80% | 3 cups |
| Beef | 8.00% | 4 oz |
| Soy | 2.90% | 3 cups |
| Casein | 9.30% | varies |
TIMING
Timing refers to pre and post exercise protein consumption. POST exercise is an ideal time to ensure QUICK protein consumption. With increased blood flow and amino acid availability, protein synthesis is at it’s best. Consumption of protein directly after vs waiting even a few hours can increase the protein synthesis potential by 3 times.
In short the ideal is to consume your total need of protein in small amounts through out the day with specific attention to pre and post exercise. Choosing protein sources that offer the highest quality of absorption will increase the body’s ability to repair muscle tissue.
