While carbohydrates may be the most popular macronutrient, the one with the most important role in our bodies is held by protein. It is probably a given that protein is important for our training recovery and lean muscle mass, but in this newsletter, we will be reviewing protein metabolism a bit further in order to better understand it’s a critical role in our physiological processes.
The protein we consume is comprised of 20 amino acids. 8 of these are essential amino acids (EAAs) and the remaining 12 are considered non-essential. EAAs are called ‘essential’ because we cannot synthesize them in our bodies and must get them through our diets. The overall purpose of protein digestion is to free these amino acids from the foods we eat. There is a constant flow and exchange of amino acids in the blood, liver, and bodily tissues – the liver being an important center for amino acid metabolism.
The primary end goal of protein digestion includes:
Forming structural proteins (skeletal muscle)
Forming functional proteins (enzymes)
Forming signaling proteins (hormones)
A multitude of cells in our body will use only the amount of amino acids they need to meet their protein requirements, and no more. The rest of the amino acids that are not utilized for protein synthesis or any other metabolic pathways will be broken down (deaminated), and their carbon skeletons are oxidized, reconstructed into another amino acid, or used for other important pathways such as glucose (gluconeogenesis) or fatty acid synthesis.
The major role of protein is different than that of carbs and fat in that its consumption serves to promote training and muscular adaptations that come from our diet and exercise programs. If we are aiming to maximize both our diet and training, we must be in a positive net muscle protein balance.