Protein, along with fat and carbohydrates is a macronutrient required by your body. Specifically, it is key to building bone, muscle, cartilage, skin, and blood. For anyone looking to add mass, notably lean mass to their physique, understanding the benefits of protein for muscle development is critical to success.
The science of protein
Proteins are composed of long chains of amino acids linked by peptide bonds. This macronutrient serves as the transport mechanism for iron, vitamins, minerals, fats, and oxygen within the body, and is the key to acid-base and fluid balance.
Essential amino acid composition, digestibility, and bioavailability determine a specific food’s protein quality. Combinations of amino acids make up all proteins. There are nine essential amino acids – those that cannot be made by the body itself. Additionally, there are another eleven nonessential amino acids – ones that the human body can make on its own. Generally, animal products contain all of the essential amino acids.
Muscles and tissues require protein to undergo the beneficial process of repairing and rebuilding, to overcome the muscular and structural damage caused by resistance training. Protein repairs this damage, in turn enabling muscle development and growth.
One of two major milk proteins. It is the liquid remaining after the milk has been curdled and strained. There are three varieties of whey – protein powder, protein concentrate, and protein isolate. All provide high levels of essential and branched chain amino acids (leucine, isoleucine, and valine).
- Whey powder is 11 – 15% protein
- Whey concentrate is 25 – 89% protein
- Whey isolate is 90+% protein
Whey is rapidly digested and absorbed and has a remarkable ability to stimulate muscle growth. its high levels of amino leucine play a key role in muscle hypertrophy (excessive growth).
Casein gives milk its white color and accounts for 70 – 80 percent of milk protein. Casein exists in a micelle – that has a hydrophobic inside and a hydrophilic outside. During digestion, casein is released as the micelle breaks down. The casein released from multiple micelles then aggregates and is digested via proteolysis, the process by which proteins are broken down into simpler, soluble compounds. Digestion is slow due to the aggregation of casein, allowing the protein to provide a sustained release of amino acids – sometimes lasting for hours.
During resistance training, a workout that produces microtears in the muscle tissue will benefit from a ready supply of amino acids delivered from protein.
The most widely used vegetable protein is soy. It is one of the only vegetable proteins that contains all of the essential amino acids. Similar to whey, soy proteins can be consumed in three types:
Flour is 50% protein (baked goods)
Concentrate is 70% protein (nutrition bars, cereals, and yogurts)
Isolate is 90% protein (sports drinks, health beverages)
Although early studies suggested that soy might decrease LDL cholesterol and blood pressure, later research failed to confirm these hypotheses.
Recommended protein intake
The recommended dietary allowance is 0.8 g/kg of body weight per day. However, individuals in active training programs that incorporate resistance training should consider consuming 1.2 to 2.0 g/kg of body weight per day. In general, 10-35% of daily calories should come from protein. Those training in specialized programs, with consultation from nutritionists and registered dieticians, may find it necessary to increase.
If you use intermittent fasting, protein should be a key nutrient for your first meal of the day.