Muscle Protein Synthesis
In part one we distilled nutrition into the basic components of caloric balance, macronutrients, meal frequency, food composition, and supplementation. In part two we discuss the basics of protein synthesis with recommendations for maximizing performance.
Protein, made up of amino acids, is a significant proportion of cells, muscles, and tissue, as well as carrying out several important bodily functions. For performance we are most interested in proteins ability to create and restore contractile tissue. Protein is in a constant state of balance within the body both being broken down (MPB), and being synthesized (MPS). When MPS exceeds MPB muscle is built (Bohe, 2001).
For MPS to exceed MPB three requirements must be met:
1. The amount of protein of the correct amounts of amino acids must exceed a stimulus threshold (Pasiakos, 2012).
2. Total caloric intake must exceed caloric expenditure or else the balance is tipped towards MPB. (Lowery, Antonio, 2012).
3. The stimulus threshold must be achieved outside of a refractory period that follows previous protein consumption.
After consuming an adequate amount of protein with the right amounts of amino acids MPS is increased for approximately two hours before declining to baseline. Following the decline is a refractory period where the body is unable to adequately respond to additional protein. The refractory period is variable but consuming adequate amounts of protein every three to five hours seems to be an optimal amount of time. (Lowery, Antonio, 2012)
Optimizing MPS can be accomplished by:
1. Resistance training.
2. Insuring the presence of insulin.
3. Consuming larger quantities of protein; subject to diminishing returns.
We already discussed the importance of resistance training… you are already doing that right? Insulin to some degree is always present in the body except in specific disease states. Insulin can be increased with the consumption of carbohydrates but also large quantities of amino acids. Insulin increase MPS and decreases MPB. And unlike the perpetual bodybuilding myth of the protein limit, consuming more protein will create greater MPS to a degree. (Robinson, 2013).
This is enough data to begin to create some general guidelines for protein consumption. Of first order: perform resistance training. Resistance training heightens MPS acutely for two hours and sustained for 24-48 hours. Consume adequate amounts of protein. My suggestion is a minimum of 30g per meal. Consume protein with the right quantities of amino acids. We have already discussed protein quality briefly. Meat and dairy sources are your best options. Soy and other incomplete or barely complete proteins are no better than water at increasing MPS (Yang, et al., 2012). Consume carbohydrates during periods of activity to heighten MPS and decrease MPB. Consume protein every three to five hours; taking into account the refractory period and to minimize the diminishing returns from consuming all protein in a single bout. Consume an adequate number of calories if looking to increase muscle.
1. Resistance training is essential
2. Consume at least 30g of protein per meal
3. Consume protein every three to five hours
4. Consume carbohydrates during periods of activity
5. Consume an adequate number of total calories to exceed caloric expenditure if looking to build muscle.
Return for part three as we discuss the creation of a nutritional plan for a hypothetical athlete.